Form 485APOS CALVERT FUND


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As filed with the Securities and Exchange Commission
on February 4, 2022

1933 Act File No. 002-76510

1940 Act File No. 811-03416

SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
 
FORM N-1A
 
  REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT of 1933
o
  POST-EFFECTIVE AMENDMENT NO. 124 x
  REGISTRATION STATEMENT
UNDER
THE INVESTMENT COMPANY ACT OF 1940
o
  AMENDMENT NO. 124 x
 
THE CALVERT FUND
(Exact Name of Registrant as Specified in Charter)
 
1825 Connecticut Ave NW, Suite 400, Washington, DC 20009
(Address of Principal Executive Offices)
 
(202) 238-2200
(Registrant’s Telephone Number)
 
DEIDRE E. WALSH
Two International Place, Boston, Massachusetts 02110
(Name and Address of Agent for Service)
 

It is proposed that this filing will become effective pursuant to Rule 485 (check appropriate box):
¨ immediately upon filing pursuant to paragraph (b) ¨ on (date) pursuant to paragraph (a)(1)
¨ on (date) pursuant to paragraph (b) x 75 days after filing pursuant to paragraph (a)(2)
¨ 60 days after filing pursuant to paragraph (a)(1) ¨ on (date) pursuant to paragraph (a)(2)
If appropriate, check the following box:
o This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

 

 

 

 

PRELIMINARY
PROSPECTUS
SUBJECT
TO COMPLETION
______________,
2022

The information in this prospectus is not complete and may be changed.
These securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This
prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where
the offer or sale would be prohibited.

 

 

Calvert Mortgage Access Fund

Class A Shares – [ ]  Class
C Shares – [ ] Class I Shares – [ ] Class R6 Shares – [ ]

Prospectus Dated
[ ], 2022

The Securities and Exchange Commission
(“SEC”) has not approved or disapproved these securities or determined if this Prospectus is truthful or complete. Any representation
to the contrary is a criminal offense.

Information in this Prospectus

  Page   Page
Fund Summary 2 Investment Objective & Principal Policies and Risks 9
Investment Objective 2 About Responsible Investing 24
Fees and Expenses of the Fund 2 Management and Organization 25
Portfolio Turnover 2 Valuing Shares 26
Principal Investment Strategies 2 Purchasing Shares 27
Principal Risks 3 Sales Charges 31
Performance 4 Redeeming Shares 33
Management 8 Shareholder Account Features 35
Purchase and Sale of Fund Shares 8 Potential Conflicts of Interest 37
Tax Information 8 Additional Tax Information 39
Payments to Broker-Dealers and Other Financial Intermediaries 8 Appendix A – The Calvert Principles for Responsible Investment 40
    Appendix B – Financial Intermediary Sales Charge Variations 42
       

This Prospectus contains important
information about the Fund and the services
available to shareholders. Please save it for reference.

 

 

Fund Summary

Investment Objective

The Fund’s investment objective is total return.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy,
hold and sell shares of the Fund. Investors may also pay commissions or other fees to their financial intermediary, which are not reflected
below. You may qualify for sales charge discounts on purchases of Class A shares if you and your family invest, or agree to invest in
the future, at least $50,000 in Calvert mutual funds. Certain financial intermediaries also may offer variations in Fund sales charges
to their customers as described in Appendix B – Financial Intermediary Sales Charge Variations in this Prospectus. More information
about these and other discounts is available from your financial professional and under “Sales Charges” on page 31 of this
Prospectus and page 19 of the Fund’s Statement of Additional Information.

Shareholder Fees (fees paid directly from your investment) Class A Class C Class I Class R6
Maximum Sales Charge (load) Imposed on Purchases (as a percentage  of offering price) 4.75% None None None
Maximum Deferred Sales Charge (load) (as a percentage of the lower of net asset value at purchase or redemption) None 1.00% None None

 

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment) Class A Class C Class I Class R6
Management Fees [  ]% [  ]% [  ]% [  ]%
Distribution and Service (12b-1) Fees [  ]% [  ]% [  ]% [  ]%
Other Expenses [  ]% [  ]% [  ]% [  ]%
Total Annual Fund Operating  Expenses [  ]% [  ]% [  ]% [  ]%

Example.
This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example
assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods.
The Example also assumes that your investment has a 5% return each year, that the operating expenses remain the same and that any expense
reimbursement arrangement remains in place for the contractual period. Although your actual costs may be higher or lower, based on these
assumptions your costs would be:

  1 Year 3 Years 5 Years 10 Years
Class A shares $[  ] $[  ] $[  ] $[  ]
Class C shares $[  ] $[  ] $[  ] $[  ]
Class I  shares $[  ] $[  ] $[  ] $[  ]
Class R6 shares $[  ] $[  ] $[  ] $[  ]

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and
sells securities (or “turns over” the portfolio). A higher portfolio turnover rate may indicate higher transaction costs and
may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating
Expenses or in the Example, affect the Fund’s performance.

Principal Investment Strategies

The Fund normally invests in mortgage related assets, which may include,
but are not limited to: agency residential mortgage-backed securities; non-agency residential mortgage backed securities; commercial mortgage-backed
securities; asset-backed securities; whole loans, loans, and other similar mortgage-related instruments. The Fund will seek to
expand homeownership access by investing in mortgages provided to underserved communities including minorities, low-income individuals
and first time homebuyers.

The Fund may also invest without limit in securities issued,
backed or otherwise guaranteed by the U.S. Government or its agencies, instrumentalities or sponsored corporations; however, the
Fund expects initially, and may thereafter continue, to invest significantly in debt securities and other income-producing
investments that involve substantially greater credit risk than those investments. The rate of interest on the debt and other
income-producing investments that the Fund may purchase may be fixed, floating, or variable. The
Fund is “non-diversified,” which means it may invest a greater percentage of its assets in the securities of a single
issuer than a “diversified” fund.

Calvert Mortgage Access Fund 2 Prospectus dated [______], 2022

The Fund will maintain an average credit rating of at least investment
grade (BBB by S&P Global Ratings (“S&P”) or Fitch Ratings (“Fitch”), or Baa by Moody’s Investors
Service (“Moody’s”)). The Fund’s average credit rating will be the weighted-average of the credit ratings of the
securities it holds directly. While the Fund’s average credit rating will be investment grade, the Fund may invest in securities
that are rated below investment grade (rated below BBB by either S&P or Fitch, or below Baa by Moody’s) or in unrated securities
considered to be of comparable quality by the investment adviser (often referred to as “junk” instruments).

The Fund may invest in mortgage-backed securities of any kind. Mortgage-backed
securities may include, among other things, securities issued, backed or otherwise guaranteed by the U.S. Government or its agencies,
instrumentalities or sponsored corporations; securities of domestic or foreign private issuers; or interests in pools of residential or
commercial mortgages. Mortgage-backed securities also include, but are not limited to, securities representing interests in, collateralized
or backed by, or whose values are determined in whole or in part by reference to, any number of mortgages or pools of mortgages or the
payment experience of such mortgages or pools of mortgages, including Real Estate Mortgage Investment Conduits (“REMICs”),
which could include re-securitizations of REMICs (“Re-REMICs”), credit default swaps, mortgage pass-through securities, mortgage
servicing rights, collateralized mortgage obligations (“CMOs”), private mortgage pass-through securities, stripped mortgage
securities (generally interest-only and principal-only securities), credit risk transfer securities, and debt instruments collateralized
or secured by other mortgage-related assets. The collateral backing mortgage-backed securities in which the Fund may invest may include,
without limitation, performing, non-performing and/or re-performing loans, non-qualifying mortgage loans, and loans secured by a single
asset and issued by a single borrower. The commercial mortgage-backed securities in which the Fund may invest may also include securitizations
backed by a single mortgage on a single property. The Fund may also invest in asset-backed securities of any type.

In pursuing its investment objective, the Fund may invest in residential
and/or commercial real estate or mortgage-related loans, construction or project finance loans, or other types of loans, which loans may
include secured and unsecured notes, senior loans, second lien loans or other types of subordinated loans, or mezzanine loans, any of
which may contain fewer or less restrictive covenants on the borrower than certain other types of loans or loans of subprime quality.

The Fund may also invest in stripped (generally interest-only and principal-only
instruments) residential and/or commercial real estate or mortgage-related loans, construction or project finance loans, or other types
of loans.

The Fund may make direct investments in individual loans or in pools
of loans and in whole loans as well as in loan participations or assignments. In addition, the Fund may itself or in conjunction with
others originate any of the foregoing types of loans. The Fund may also be involved in, or finance, the origination of loans to legal
entities or individuals.

The Fund may invest in any level of the capital structure of an issuer
of mortgage- or asset-backed securities, including subordinated or residual tranches and the equity or “first loss” tranche.
The Fund may invest in mortgage- or asset-backed securities that are designed to have leveraged investment exposure to the underlying
mortgages or assets. The Fund may also gain or adjust its exposure to mortgage- or asset-backed securities through derivatives, such as
credit default swap or futures transactions. The Fund may also invest in certain residential mortgage-backed securities (RMBS) including
but not limited to credit risk transfer securities that, while not backed by mortgage loans, have credit exposure to a pool of mortgage
loans acquired by the government-sponsored entity or private entity issuing the securities.

Certain mortgage- and other asset-backed securities in which the Fund
may invest may represent an inverse interest-only class of security for which the holders are entitled to receive no payments of principal
and are entitled only to receive interest at a rate that will vary inversely with a specified index or reference rate, or a multiple thereof.

The Fund also may invest in other U.S. government securities, including,
but not limited to, U.S. Treasury bills, notes and bonds, securities (including mortgage-backed securities) issued by agencies or instrumentalities
of the U.S. Government which may or may not be backed by the full faith and credit of the United States, and securities issued by agencies
or instrumentalities which are backed solely by the credit of the issuing agency or instrumentality.

The Fund may also invest in restricted and illiquid securities.

The Fund may use various derivative strategies for hedging purposes,
to gain, or reduce, long or short exposure to one or more asset classes, issuers, or reference assets, or to manage the dollar-weighted
average effective duration of the Fund’s portfolio. The Fund also may enter into derivatives transactions with the purpose or effect
of creating investment leverage. Additional leverage will increase the volatility of the Fund’s investment portfolio and could result
in larger losses or gains than if the strategies were not used. Transactions in derivative instruments may include but are not limited
to: the purchase or sale of futures contracts on securities, indices or other financial instruments or currencies; options on futures
contracts; exchange-traded and over-the-counter options on securities, indices, currencies and other instruments; and interest rate, credit
default, inflation and total return swaps. The Fund may take short or long positions with regard to

Calvert Mortgage Access Fund 3 Prospectus dated [______], 2022

certain synthetic total return swap indices. The Fund may use interest
rate swaps and options on interest rate swaps for risk management purposes and not as a speculative investment and would typically use
interest rate swaps to shorten the average interest rate reset time of its holdings. The Fund may engage in other derivatives to seek
return, to hedge against fluctuations in securities prices, interest rates or currency exchange rates, to change the duration of obligations
held by the Fund, to manage certain investment risks and/or as a substitute for the purchase or sale of securities or currencies. There
is no stated limit on the Fund’s use of derivatives.

The portfolio managers may also use other active management techniques,
such as mortgage dollar roll transactions, forward commitments, repurchase agreements, reverse repurchase agreements and any combination
thereof. The Fund may enter into forward commitments to buy or sell agency MBS (to-be-announced transactions, or “TBAs”).
The Fund may engage in short sales of securities. The Fund may borrow from banks for investment purposes.

The portfolio managers seek to purchase securities believed to be the
best relative value with regard to price, yield, and expected total return in relation to other available instruments. Investment decisions
are primarily made on the basis of fundamental research and relative value and the consideration of the responsible investment criteria
described below.  The portfolio managers may sell a security when they believe the security no longer represents the best relative
value and the fundamental research or cash needs dictate.

Responsible
Investing.
In selecting investments for the Fund, CRM is guided by The Calvert Principles for Responsible Investment (“Principles”)
(a copy of which is included as an appendix to the Fund’s Prospectus), which provide a framework for considering environmental,
social and governance (“ESG”) factors. The Fund generally invests in issuers that are believed by CRM to operate in accordance
with the Principles and may also invest in issuers that CRM believes are likely to operate in accordance with the Principles pending CRM’s
engagement activity with such issuer.

Principal Risks

Market Risk.
The value of investments held by the Fund may increase or decrease in response to economic, political, financial, public health crises
(such as epidemics or pandemics) or other disruptive events (whether real, expected or perceived) in the U.S. and global markets. These
events may negatively impact broad segments of businesses and populations and may exacerbate pre-existing risks to the Fund. The frequency
and magnitude of resulting changes in the value of the Fund’s investments cannot be predicted. Certain securities and other investments
held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in reaction to changing market
conditions. Monetary and/or fiscal actions taken by U.S. or foreign governments to stimulate or stabilize the global economy may not be
effective and could lead to high market volatility. No active trading market may exist for certain investments held by the Fund, which
may impair the ability of the Fund to sell or to realize the full value of such investments in the event of the need to liquidate such
assets.

U.S. Government
Securities Risk.
Although certain U.S. Government-sponsored agencies (such as the Federal Home Loan Mortgage Corporation and
the Federal National Mortgage Association) may be chartered or sponsored by acts of Congress, their securities are neither issued nor
guaranteed by the U.S. Treasury. U.S. Treasury securities generally have a lower return than other obligations because of their higher
credit quality and market liquidity.

Mortgage-
and Asset-Backed Securities Risk.
Mortgage- and asset-backed securities represent interests in “pools” of commercial
or residential mortgages or other assets, including consumer loans or receivables. Movements in interest rates (both increases and decreases)
may quickly and significantly reduce the value of certain types of mortgage- and asset-backed securities. Although certain mortgage- and
asset-backed securities are guaranteed as to timely payment of interest and principal by a government entity, the market price for such
securities is not guaranteed and will fluctuate. The purchase of mortgage- and asset-backed securities issued by non-government entities
may entail greater risk than such securities that are issued or guaranteed by a government entity. Mortgage- and asset-backed securities
issued by non-government entities may offer higher yields than those issued by government entities, but may also be subject to greater
volatility than government issues and can also be subject to greater credit risk and the risk of default on the underlying mortgages or
other assets. Investments in mortgage- and asset-backed securities are subject to both extension risk, where borrowers pay off their debt
obligations more slowly in times of rising interest rates, and prepayment risk, where borrowers pay off their debt obligations sooner
than expected in times of declining interest rates.

Privately
Issued Mortgage-Related Securities Risk.
There are no direct or indirect government or agency guarantees of payments in pools
created by non-governmental issuers. Privately issued mortgage related securities are also not subject to the same underwriting requirements
for the underlying mortgages that are applicable to those mortgage-related securities that have a government or government-sponsored entity
guarantee. Privately issued mortgage-related securities are not traded on an exchange and there may be a limited market for the securities,
especially when there is a perceived weakness in the mortgage and real estate market sectors. Without an active trading market, mortgage-related
securities held in a Fund’s portfolio may be particularly difficult to value because of the complexities involved in assessing the
value of the underlying mortgage loans.

Calvert Mortgage Access Fund 4 Prospectus dated [______], 2022

Real Estate
Risk.
Real estate investments are subject to risks associated with owning real estate, including declines in real estate values,
increases in property taxes, fluctuations in interest rates, limited availability of mortgage financing, decreases in revenues from underlying
real estate assets, declines in occupancy rates, changes in government regulations affecting zoning, land use, and rents, environmental
liabilities, and risks related to the management skill and creditworthiness of the issuer. Companies in the real estate industry may also
be subject to liabilities under environmental and hazardous waste laws, among others. REITs must satisfy specific requirements for favorable
tax treatment and can involve unique risks in addition to the risks generally affecting the real estate industry. Changes in underlying
real estate values may have an exaggerated effect to the extent that investments are concentrated in particular geographic regions or
property types.

Risks of
Repurchase Agreements and Reverse Repurchase Agreements.
In the event of the insolvency of the counterparty to a repurchase
agreement or reverse repurchase agreement, recovery of the repurchase price owed to the Fund or, in the case of a reverse repurchase agreement,
the securities sold by the Fund, may be delayed. In a repurchase agreement, such insolvency may result in a loss to the extent that the
value of the purchased securities decreases during the delay or that value has otherwise not been maintained at an amount equal to the
repurchase price. In a reverse repurchase agreement, the counterparty’s insolvency may result in a loss equal to the amount by which
the value of the securities sold by the Fund exceeds the repurchase price payable by the Fund; if the value of the purchased securities
increases during such a delay, that loss may also be increased. When the Fund enters into a reverse repurchase agreement, any fluctuations
in the market value of either the securities sold to the counterparty or the securities which the Fund purchases with its proceeds from
the agreement would affect the value of the Fund’s assets. As a result, such agreements may increase fluctuations in the net asset
value of the Fund’s shares. Because reverse repurchase agreements may be considered to be a form of borrowing by the Fund (and a
loan from the counterparty), they constitute leverage. If the Fund reinvests the proceeds of a reverse repurchase agreement at a rate
lower than the cost of the agreement, entering into the agreement will lower the Fund’s yield.

Restricted
Securities Risk.
Unless registered for sale to the public under applicable federal securities law, restricted securities can
be sold only in private transactions to qualified purchasers pursuant to an exemption from registration. The sale price realized from
a private transaction could be less than the Fund’s purchase price for the restricted security. It may be difficult to identify
a qualified purchaser for a restricted security held by the Fund and such security could be deemed illiquid. It may also be more difficult
to value such securities.

Stripped
Securities Risk.
Stripped Securities (“Strips”) are usually structured with classes that receive different proportions
of the interest and principal distributions from an underlying asset or pool of underlying assets. Classes may receive only interest distributions
(interest-only “IO”) or only principal (principal-only “PO”). Strips are particularly sensitive to changes in
interest rates because this may increase or decrease prepayments of principal. A rapid or unexpected increase in prepayments can significantly
depress the value of IO Strips, while a rapid or unexpected decrease can have the same effect on PO Strips.

Industry Concentration Risk. Because the Fund concentrates its
investments in the real estate industry, the value of Fund shares may be affected by events that adversely affect that industry and may
fluctuate more than that of a fund that invests more broadly.

Issuer Diversification
Risk.
The Fund is “non-diversified,” which means it may invest a greater percentage of its assets in the securities
of a single issuer than a fund that is “diversified.” Non-diversified funds may focus their investments in a small number
of issuers, making them more susceptible to risks affecting such issuers than a more diversified fund might be.

Sector Risk.
Because the Fund may, under certain market conditions, invest a significant portion of its assets in one or more sectors, the value of
Fund shares may be affected by events that adversely affect a particular sector and may fluctuate more than that of a Fund that invests
more broadly.

Credit Risk.
Investments in fixed income and other debt obligations (referred to below as “debt instruments”) are subject to the risk of
non-payment of scheduled principal and interest. Changes in economic conditions or other circumstances may reduce the capacity of the
party obligated to make principal and interest payments on such instruments and may lead to defaults. Such non-payments and defaults may
reduce the value of Fund shares and income distributions. The value of debt instruments also may decline because of concerns about the
issuer’s ability to make principal and interest payments. In addition, the credit ratings of debt instruments may be lowered if
the financial condition of the party obligated to make payments with respect to such instruments deteriorates. In the event of bankruptcy
of the issuer of a debt instrument, the Fund could experience delays or limitations with respect to its ability to realize the benefits
of any collateral securing the instrument. In order to enforce its rights in the event of a default, bankruptcy or similar situation,
the Fund may be required to retain legal or similar counsel, which may increase the Fund’s operating expenses and adversely affect
net asset value.

Lower Rated
Investments Risk.
Investments rated below investment grade and comparable unrated investments (sometimes referred to as “junk”)
have speculative characteristics because of the credit risk associated with their issuers. Changes in economic conditions or other circumstances
typically have a greater effect on the ability of issuers of lower rated investments to make principal and interest payments than they
do on issuers of higher rated investments. An economic downturn generally leads to a higher non-payment rate, and a lower rated investment
may lose significant value before a default occurs. Lower rated investments typically are subject to greater price volatility and illiquidity
than higher rated investments.

Calvert Mortgage Access Fund 5 Prospectus dated [______], 2022

Interest
Rate Risk.
In general, the value of income securities will fluctuate based on changes in interest rates. The value of
these securities is likely to increase when interest rates fall and decline when interest rates rise. Duration measures a
fixed-income security’s price sensitivity to changes in the general level of interest rates. Generally, securities with longer
durations or maturities are more sensitive to changes in interest rates than securities with shorter durations or maturities,
causing them to be more volatile. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but
may provide lower returns than fixed-income securities with longer durations or maturities. Funds with shorter average durations
(including the Fund) may own individual investments that have longer durations than the average duration of the Fund. In a rising
interest rate environment, the duration of income securities that have the ability to be prepaid or called by the issuer may be
extended. In a declining interest rate environment, the proceeds from prepaid or maturing instruments may have to be reinvested at a
lower interest rate. Certain instruments held by the Fund pay an interest rate based on the London Interbank Offered Rate
(“LIBOR”), which is the average offered rate for various maturities of short-term loans between certain major
international banks. LIBOR is used throughout global banking and financial industries to determine interest rates for a variety of
financial instruments (such as debt instruments and derivatives) and borrowing arrangements. The ICE Benchmark Administration
Limited, the administrator of LIBOR, ceased publishing certain LIBOR settings on December 31, 2021, and is expected to cease
publishing the remaining LIBOR settings on June 30, 2023. Although the transition process away from LIBOR has become increasingly
well defined the impact on certain debt securities, derivatives and other financial
instruments that utilize LIBOR remains uncertain. The phase-out of LIBOR may result in, among other things, increased volatility or
illiquidity in markets for instruments based on LIBOR and changes in the value of such instruments.

Additional
Risks of Loans.
Loans are traded in a private, unregulated inter-dealer or inter-bank resale market and are generally subject
to contractual restrictions that must be satisfied before a loan can be bought or sold. These restrictions may impede the Fund’s
ability to buy or sell loans (thus affecting their liquidity) and may negatively impact the transaction price. See also “Market
Risk” above. It also may take longer than seven days for transactions in loans to settle. Due to the possibility of an extended
loan settlement process, the Fund may hold cash, sell investments or temporarily borrow from banks or other lenders to meet short-term
liquidity needs, such as to satisfy redemption requests from Fund shareholders. The types of covenants included in loan agreements generally
vary depending on market conditions, the creditworthiness of the issuer, the nature of the collateral securing the loan and possibly other
factors. Loans with fewer covenants that restrict activities of the borrower may provide the borrower with more flexibility to take actions
that may be detrimental to the loan holders and provide fewer investor protections in the event of such actions or if covenants are breached.
The Fund may experience relatively greater realized or unrealized losses or delays and expense in enforcing its rights with respect to
loans with fewer restrictive covenants. Loans to entities located outside of the U.S. may have substantially different lender protections
and covenants as compared to loans to U.S. entities and may involve greater risks. The Fund may have difficulties and incur expense enforcing
its rights with respect to non-U.S. loans and such loans could be subject to bankruptcy laws that are materially different than in the
U.S. Loans may be structured such that they are not securities under securities law, and in the event of fraud or misrepresentation by
a borrower, lenders may not have the protection of the anti-fraud provisions of the federal securities laws. Loans are also subject to
risks associated with other types of income investments, including credit risk and risks of lower rated investments.

Derivatives
Risk.
The Fund’s exposure to derivatives involves risks different from, or possibly greater than, the risks associated
with investing directly in securities and other investments. The use of derivatives can lead to losses because of adverse movements in
the price or value of the security, instrument, index, currency, commodity, economic indicator or event underlying a derivative (“reference
instrument”), due to failure of a counterparty or due to tax or regulatory constraints. Derivatives may create leverage in the Fund,
which represents a non-cash exposure to the underlying reference instrument. Leverage can increase both the risk and return potential
of the Fund. Derivatives risk may be more significant when derivatives are used to enhance return or as a substitute for a cash investment
position, rather than solely to hedge the risk of a position held by the Fund. Use of derivatives involves the exercise of specialized
skill and judgment, and a transaction may be unsuccessful in whole or in part because of market behavior or unexpected events. Changes
in the value of a derivative (including one used for hedging) may not correlate perfectly with the underlying reference instrument. Derivative
instruments traded in over-the-counter markets may be difficult to value, may be illiquid, and may be subject to wide swings in valuation
caused by changes in the value of the underlying reference instrument. If a derivative’s counterparty is unable to honor its commitments,
the value of Fund shares may decline and the Fund could experience delays in the return of collateral or other assets held by the counterparty.
The loss on derivative transactions may substantially exceed the initial investment, particularly when there is no stated limit on the
Fund’s use of derivatives. A derivative investment also involves the risks relating to the reference instrument underlying the investment.

When-Issued
and Forward Commitment Risk.
Securities purchased on a when-issued or forward commitment basis are subject to the risk that
when delivered they will be worth less than the agreed upon payment price.

Calvert Mortgage Access Fund 6 Prospectus dated [______], 2022

Borrowing
Risk.
 Borrowing cash to increase investments (sometimes referred to as “leverage”) may exaggerate the effect
on the Fund’s net asset value of any increase or decrease in the value of the security purchased with the borrowing. There can be
no assurance that the use of borrowings will be successful. In connection with its borrowings, the Fund will be required to maintain specified
asset coverage with respect to such borrowings by applicable federal securities laws and the terms of its credit facility with the lender.
The Fund may be required to dispose of portfolio investments on unfavorable terms if market fluctuations or other factors cause the required
asset coverage to be less than the prescribed amount. Borrowings involve additional expense to the Fund.

Leverage
Risk.
Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an underlying reference
instrument. Leverage can increase both the risk and return potential of the Fund. The Fund is required to segregate liquid assets or otherwise
cover the Fund’s obligation created by a transaction that may give rise to leverage. The use of leverage may cause the Fund to liquidate
portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet segregation requirements. Leverage
may cause the Fund’s share price to be more volatile than if it had not been leveraged, as certain types of leverage may exaggerate
the effect of any increase or decrease in the value of the Fund’s portfolio securities. The loss on leveraged investments may substantially
exceed the initial investment.

Short Sale
Risk.
The Fund will incur a loss as a result of a short sale if the price of the security sold short increases in value between
the date of the short sale and the date on which the Fund purchases the security to replace the borrowed security. In addition, a lender
may request, or market conditions may dictate, that securities sold short be returned to the lender on short notice, and the Fund may
have to buy the securities sold short at an unfavorable price and/or may have to sell related long positions before it had intended to
do so. The Fund may not be able to successfully implement its short sale strategy due to limited availability of desired securities or
for other reasons. The Fund may also be required to pay a premium and other transaction costs, which would increase the cost of the security
sold short. The amount of any gain will be decreased and the amount of any loss increased, by the amount of the premium, dividends, interest
or expenses the Fund may be required to pay in connection with the short sale. Because losses on short sales arise from increases in the
value of the security sold short, the Fund’s losses are potentially unlimited in a short sale transaction. Short sales could be
speculative transactions and involve special risks, including greater reliance on the investment adviser’s ability to accurately
anticipate the future value of a security.

Liquidity
Risk.
The Fund is exposed to liquidity risk when trading volume, lack of a market maker or trading partner, large position
size, market conditions, or legal restrictions impair its ability to sell particular investments or to sell them at advantageous market
prices. Consequently, the Fund may have to accept a lower price to sell an investment or continue to hold it or keep the position open,
sell other investments to raise cash or abandon an investment opportunity, any of which could have a negative effect on the Fund’s
performance. These effects may be exacerbated during times of financial or political stress.

Money Market
Instrument Risk.
Money market instruments may be adversely affected by market and economic events, such as a sharp rise in
prevailing short-term interest rates; adverse developments in the banking industry, which issues or guarantees many money market instruments;
adverse economic, political or other developments affecting issuers of money market instruments; changes in the credit quality of issuers;
and default by a counterparty.

Portfolio
Turnover Risk.
The annual portfolio turnover rate of the Fund may exceed 100%. A mutual fund with a high turnover rate (100%
or more) may generate more capital gains and may involve greater expenses (which may reduce return) than a fund with a lower rate. Capital
gains distributions will be made to shareholders if offsetting capital loss carry forwards do not exist.

Risks Associated
with Active Management.
The success of the Fund’s investment strategy depends on portfolio management’s successful
application of analytical skills and investment judgment. Active management involves subjective decisions.

Responsible
Investing Risk.
Investing primarily in responsible investments carries the risk that, under certain market conditions, the
Fund may underperform funds that do not utilize a responsible investment strategy. The application of responsible investment criteria
may affect the Fund’s exposure to certain sectors or types of investments, and may impact the Fund’s relative investment performance
depending on whether such sectors or investments are in or out of favor in the market. An investment’s ESG performance or the investment
adviser’s assessment of such performance may change over time, which could cause the Fund to temporarily hold securities that do not comply
with the Fund’s responsible investment criteria. In evaluating an investment, the investment adviser is dependent upon information
and data that may be incomplete, inaccurate or unavailable, which could adversely affect the analysis of the ESG factors relevant to a
particular investment. Successful application of the Fund’s responsible investment strategy will depend on the investment adviser’s
skill in properly identifying and analyzing material ESG issues.

Calvert Mortgage Access Fund 7 Prospectus dated [______], 2022

 

General
Fund Investing Risks.
The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its
investment objective. It is possible to lose money by investing in the Fund. The Fund is designed to be a long-term investment vehicle
and is not suited for short-term trading. Investors in the Fund should have a long-term investment perspective and be able to tolerate
potentially sharp declines in value. Purchase and redemption activities by Fund shareholders may impact the management of the Fund and
its ability to achieve its investment objective(s). In addition, the redemption by one or more large shareholders or groups of shareholders
of their holdings in the Fund could have an adverse impact on the remaining shareholders in the Fund. The Fund relies on various service
providers, including the investment adviser, in its operations and is susceptible to operational, information security and related events
(such as public health crises, cyber or hacking attacks) that may affect the service providers or the services that they provide to the
Fund. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation
or any other government agency.

Performance

Performance history will be available for the Fund after the Fund has
been in operation for one full calendar year.

Management

Investment
Adviser.
Calvert Research and Management (“CRM” or the “Adviser”).

Portfolio Managers

Andrew Szczurowski,
Vice President of CRM, has managed the Fund since its inception in [ ] 2022.

Alexander
Payne,
Vice President of CRM, has managed the Fund since its inception in [ ] 2022.

Purchase and Sale of Fund Shares

You may purchase, redeem or exchange Fund shares on any business day,
which is any day the New York Stock Exchange is open for business. You may purchase, redeem or exchange Fund shares either through your
financial intermediary or (except for purchases of Class C shares by accounts with no specified financial intermediary) directly from
the Fund either by writing to the Fund, P.O. Box 219544, Kansas City, MO 64121-9544, or by calling 1-800-368-2745. The minimum initial
purchase or exchange into the Fund is $1,000 for Class A and Class C, $250,000 for Class I and $1,000,000 for Class R6 (waived in certain
circumstances). There is no minimum for subsequent investments.

Tax Information

If your shares are held in a taxable account, the Fund’s distributions
will be taxed to you as ordinary income and/or capital gains, unless you are exempt from taxation. If your shares are held in a tax-advantaged
account, you will generally be taxed only upon withdrawals from the account.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund’s shares through a broker-dealer or other
financial intermediary (such as a bank) (collectively, “financial intermediaries”), the Fund, its principal underwriter and
its affiliates may pay the financial intermediary for the sale of Fund shares and related services. These payments may create a conflict
of interest by influencing the financial intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson
or visit your financial intermediary’s website for more information.

 

Calvert Mortgage Access Fund 8 Prospectus dated [______], 2022

 

Investment Objective & Principal Policies and Risks

The investment objective and principal investment policies and risks
of the Fund are described in its Fund Summary. Set forth below is additional information about such policies and risks, as well as information
about other types of investments and practices in which the Fund may engage from time to time. See also “Strategies and Risks”
in the Statement of Additional Information (“SAI”).

Definitions.
As used herein, the following terms have the indicated meaning: “1940 Act” means the Investment Company Act of 1940, as amended;
“1933 Act” means the Securities Act of 1933, as amended; “Code” means the Internal Revenue Code of 1986, as amended;
“ERISA” means the Employee Retirement Income Security Act of 1974, as amended; and “investment adviser” means
the Fund’s investment adviser but if the Fund is sub-advised, it refers to the sub-adviser(s) providing day-to-day management with
respect to the investments or strategies discussed.

U.S. Treasury
and Government Securities.
U.S. Treasury securities (“Treasury Securities”) include U.S. Treasury obligations that
differ in their interest rates, maturities and times of issuance. U.S. Government agency securities (“Agency Securities”)
include obligations issued or guaranteed by U.S. Government agencies or instrumentalities and government-sponsored enterprises. Agency
Securities may be guaranteed by the U.S. Government or they may be backed by the right of the issuer to borrow from the U.S. Treasury,
the discretionary authority of the U.S. Government to purchase the obligations, or the credit of the agency, instrumentality or enterprise.

Government-sponsored enterprises, such as the Federal Home Loan Mortgage
Corporation (“Freddie Mac”), the Federal National Mortgage Association (“Fannie Mae”), the Federal Home Loan Banks
(“FHLBs”), the Private Export Funding Corporation (“PEFCO”), the Federal Deposit Insurance Corporation (“FDIC”),
the Federal Farm Credit Banks (“FFCB”) and the Tennessee Valley Authority (“TVA”), although chartered or sponsored
by Congress, are not funded by congressional appropriations and the debt and mortgage-backed securities issued by them are neither guaranteed
nor issued by the U.S. Government. Treasury Securities and Agency Securities also include any security or agreement collateralized or
otherwise secured by Treasury Securities or Agency Securities, respectively.

Because of their high credit quality and market liquidity, U.S. Treasury
and Agency Securities generally provide a lower current return than obligations of other issuers. While the U.S. Government has provided
financial support to Fannie Mae and Freddie Mac in the past, there can be no assurance that it will support these or other government-sponsored
enterprises in the future.

Mortgage-Backed
Securities (“MBS”).
 MBS represent participation interests in pools of adjustable and fixed-rate mortgage
loans. MBS may be issued by the U.S. Government (or one of its agencies or instrumentalities) or privately issued but collateralized by
mortgages that are insured, guaranteed or otherwise backed by the U.S. Government, or its agencies or instrumentalities. Adjustable rate
mortgages are mortgages whose interest rates are periodically reset when market rates change. Unlike conventional debt obligations, MBS
provide monthly payments derived from the monthly interest and principal payments (including any prepayments) made by the individual borrowers
on the pooled mortgage loans.

MBS include classes of collateralized mortgage obligations (“CMOs”),
including fixed- or floating-rate tranches, and various other MBS. In choosing among CMO classes, the investment adviser will evaluate
the total income potential of each class and other factors.

MBS issued by non-government entities are subject to the risks that
the underlying mortgage borrowers fail to make timely payments of interest and principal and that any guarantee or other structural feature,
if present, is insufficient to enable the timely payment of interest and principal on the MBS. Although certain MBS are guaranteed as
to timely payment of interest and principal by a government-sponsored entity, the market price for such securities is not guaranteed and
will fluctuate.

The mortgage loans underlying MBS are generally subject to a greater
rate of principal prepayments in a declining interest rate environment and to a lesser rate of principal prepayments in an increasing
interest rate environment, although investment in seasoned MBS can mitigate this risk. Under certain interest and prepayment rate scenarios,
the Fund may fail to recover the full amount of its investment in MBS, notwithstanding any direct or indirect governmental or agency guarantee.
Because faster than expected prepayments must usually be invested in lower yielding securities, MBS are less effective than conventional
bonds in “locking in” a specified interest rate. For premium bonds, the risk of prepayment may be enhanced. In a rising interest
rate environment, a declining prepayment rate will extend the average life of many MBS. This possibility is often referred to as extension
risk. Extending the average life of a mortgage-backed security increases the risk of depreciation due to future increases in market interest
rates. MBS that are purchased at a premium generate current income that exceeds market rates for comparable investments, but tend to decrease
in value as they mature.

Calvert Mortgage Access Fund 9 Prospectus dated [______], 2022

 

CMOs are subject to the same types of risks affecting MBS as described
above. CMOs with complex or highly variable prepayment terms generally entail greater market and liquidity risks than other MBS. For example,
their prices are more volatile and their trading market may be more limited. The structure of certain CMO interests held by the Fund may
cause the Fund to be paid interest and/or principal on its investment only after holders of other interests in that particular CMO have
received the full repayment of principal or interest on their investments.

Mortgage dollar rolls involve the Fund selling MBS for delivery in the
current month with a simultaneous contract entered to repurchase substantially similar (same type, coupon and maturity) securities on
a specified future date (a “mortgage roll”). During the roll period, the Fund forgoes principal and interest paid on the MBS.

MBS that include loans that have had a history of refinancing opportunities
are referred to as “seasoned MBS.” MBS that are not seasoned MBS are referred to as generic MBS. Seasoned MBS tend to have
a higher collateral to debt ratio than other MBS because a greater percentage of the underlying debt has been repaid and the collateral
property may have appreciated in value. MBS may be “premium bonds” acquired at prices that exceed their par or principal value.

Asset-Backed
Securities.
 Asset-backed securities represent interests in a pool of assets other than mortgages, such as home equity
loans, automobile receivables or credit card receivables. Most asset-backed securities involve consumer or commercial debts with maturities
of less than 10 years. However, almost any type of fixed-income asset (including other fixed-income securities) may be used to create
an asset-backed security. Asset-backed securities may take the form of commercial paper, notes or pass-through certificates. A structured
asset-backed security is a multiclass instrument that is typically backed by a pool of auto loans, credit card receivables, home equity
loans or student loans.

Unscheduled prepayments of asset-backed securities may result in a loss
of income if the proceeds are invested in lower-yielding securities. Conversely, in a rising interest rate environment, a declining prepayment
rate will extend the average life of many asset-backed securities, which increases the risk of depreciation due to future increases in
market interest rates. In addition, issuers of asset-backed securities may have limited ability to enforce the security interest in the
underlying assets, and credit enhancements (if any) may be inadequate in the event of default. Asset-backed securities may experience
losses on the underlying assets as a result of certain rights provided to consumer debtors under federal and state law. The value of asset-backed
securities may be affected by the factors described above and other factors, such as interest rate risk, the availability of information
concerning the pool and its structure, the creditworthiness of the servicing agent for the pool, the originator of the underlying assets
or the entities providing credit enhancements and the ability of the servicer to service the underlying collateral. The value of asset-backed
securities representing interests in a pool of utilities receivables may be adversely affected by changes in government regulations. Under
certain market conditions, asset-backed securities may be less liquid and may be difficult to value. If a structured asset-backed security
is subordinated to other classes backed by the same pool of collateral, the likelihood that it will make payments of principal may be
substantially limited.

Commercial
Mortgage-Backed Securities.
 Commercial mortgage-backed securities (“CMBS”) include securities that reflect
an interest in, and are secured by, mortgage loans on commercial real property, such as loans for hotels, shopping centers, office buildings
and apartment buildings. Generally, the interest and principal payments on these loans are passed on to investors in CMBS according to
a schedule of payments.

CMBS are subject to the risks described under “Asset-Backed Securities”
above. CMBS also are subject to many of the risks of investing in the real estate securing the underlying mortgage loans and are therefore
different from the risks of other types of mortgage-backed securities. These risks reflect the effects of local and other economic conditions
on real estate markets, the ability of tenants to make loan payments, and the ability of a property to attract and retain tenants. CMBS
may be less liquid and exhibit a greater price volatility than other types of mortgage- or asset-backed securities. The Fund’s direct
and indirect investments in CMBS will not exceed 25% of its net assets. For the purposes of the Fund’s industry concentration policy,
CMBS will be categorized based on the underlying assets of the CMBS (retail, office, warehouse, multifamily, defeased collateral, etc.).

The commercial mortgage loans that underlie CMBS have certain distinct
risk characteristics. Commercial mortgage loans generally lack standardized terms, which may complicate their structure, tend to have
shorter maturities than residential mortgage loans and may not be fully amortizing. Commercial properties themselves tend to be unique
and are more difficult to value than single-family residential properties. In addition, commercial properties, particularly industrial
and warehouse properties, are subject to environmental risks and the burdens and costs of compliance with environmental laws and regulations.

Residential
Mortgage-Backed Securities Risk.
Residential mortgage-backed securities (“RMBS”) represent participation interests
in pools of adjustable and fixed-rate mortgage loans. RMBS may be (i) issued by the U.S. Government (or one of its agencies or instrumentalities),
(ii) privately issued but collateralized by mortgages that are insured, guaranteed or otherwise backed by the U.S. Government, or its
agencies or instrumentalities or (iii) privately issued but collateralized by mortgages that are not insured, guaranteed or otherwise
backed by the U.S. Government, or its agencies or instrumentalities. Adjustable rate mortgages are mortgages whose interest rates are
periodically reset when market rates change. Unlike conventional debt obligations, RMBS provide monthly payments derived from the monthly
interest and principal payments (including any prepayments) made by the individual borrowers on the pooled mortgage loans.

Calvert Mortgage Access Fund 10 Prospectus dated [______], 2022

RMBS include classes of collateralized mortgage obligations
(“CMOs”), including fixed- or floating-rate tranches, and various other RMBS. In choosing among CMO classes, the investment
adviser will evaluate the total income potential of each class and other factors.

RMBS also include credit risk transfer securities that, while
not backed by mortgage loans, have credit exposure to a pool of mortgage loans. Credit risk transfer securities may be issued by government-sponsored
entities or private entities.

RMBS issued by non-government entities are subject to the risks
that the underlying mortgage borrowers fail to make timely payments of interest and principal and that any guarantee or other structural
feature, if present, is insufficient to enable the timely payment of interest and principal on the RMBS. Although certain RMBS are guaranteed
as to timely payment of interest and principal by a government-sponsored entity, the market price for such securities is not guaranteed
and will fluctuate.

The mortgage loans underlying RMBS are generally subject to
a greater rate of principal prepayments in a declining interest rate environment and to a lesser rate of principal prepayments in an increasing
interest rate environment. Under certain interest and prepayment rate scenarios, the Fund may fail to recover the full amount of its investment
in RMBS, notwithstanding any direct or indirect governmental or agency guarantee. Because faster than expected prepayments must usually
be invested in lower yielding securities, RMBS are less effective than conventional bonds in “locking in” a specified interest
rate. For premium bonds, the risk of prepayment may be enhanced. In a rising interest rate environment, a declining prepayment rate will
extend the average life of many RMBS. This possibility is often referred to as extension risk. Extending the average life of a mortgage-backed
security increases the risk of depreciation due to future increases in market interest rates. RMBS that are purchased at a premium generate
current income that exceeds market rates for comparable investments, but tend to decrease in value as they mature.

CMOs are subject to the same types of risks affecting RMBS
as described above. CMOs with complex or highly variable prepayment terms generally entail greater market and liquidity risks than other
RMBS. For example, their prices are more volatile and their trading market may be more limited. The structure of certain CMO interests
held by the Fund may cause the Fund to be paid interest and/or principal on its investment only after holders of other interests in that
particular CMO have received the full repayment of principal or interest on their investments.

Mortgage dollar rolls involve the Fund selling RMBS for delivery
in the current month with a simultaneous contract entered to repurchase substantially similar (same type, coupon and maturity) securities
on a specified future date (a “mortgage roll”). During the roll period, the Fund forgoes principal and interest paid on the
RMBS.

Stripped
Securities.
Stripped Securities (“Strips”) are usually structured with classes that receive different proportions
of the interest and principal distributions from an underlying asset or pool of assets. Some structures may have a class that receives
only interest from the underlying assets, interest-only (“IO”) class, while another class may receive only principal, principal-only
(“PO”) class. IO and PO Strips may be purchased for their return and/or hedging characteristics. Because of their structure,
IO Strips may move differently than typical fixed-income securities in relation to changes in interest rates. In addition to Strips issued
by the U.S. Government, its agencies or instrumentalities, Strips may also be issued by private originators or investors, including depository
institutions, banks, investment banks and special purpose subsidiaries of these entities.

Strips are particularly sensitive to changes in interest rates because
these changes may impact the frequency of principal payments (including prepayments) on the underlying assets or pool of underlying assets.
While the U.S. Government or its agencies or instrumentalities may guarantee the full repayment of principal on Strips they issue, repayment
of interest is guaranteed only while the underlying assets or pools of assets are outstanding. IO Strips tend to decrease in value if
prepayments are greater than anticipated and increase in value if prepayments are less than anticipated. Conversely, PO Strips tend to
increase in value if prepayments are greater than anticipated and decline if prepayments are less than anticipated. To the extent the
Fund invests in Strips, rapid changes in the rate of prepayments may have a measurably adverse effect on the Fund’s performance.
In addition, the secondary market for Strips may be less liquid than that for other securities.

Liquidity
Risk.
The Fund is exposed to liquidity risk when trading volume, lack of a market maker, or legal restrictions impair the
Fund’s ability to sell particular investments or close derivative positions at an advantageous market price. Trading
opportunities are also more limited for securities and other instruments that are not widely held or are traded in less developed
markets. These factors may make it more difficult to sell or buy a security at a favorable price or time. Consequently, the Fund may
have to accept a lower price to sell an investment or continue to hold it or keep the position open, sell other investments to raise
cash or abandon an investment opportunity, any of which could have a negative effect on the Fund’s performance. It also may be
more difficult to value less liquid investments. These effects may be exacerbated during times of financial or political stress.
Increased Fund redemption activity also may increase liquidity risk due to the need of the Fund to sell portfolio investments and
may negatively impact Fund performance.

Calvert Mortgage Access Fund 11 Prospectus dated [______], 2022

The Fund will not acquire any illiquid investment if, immediately after
the acquisition, the Fund will have invested more than 15% of its net assets in illiquid investments. Illiquid investments mean any investments
that the Fund’s investment adviser and/or sub-adviser, as applicable, reasonably expect cannot be sold or disposed of in seven calendar
days or less under then-current market conditions without the sale or disposition significantly changing the market value of the investment.

Restricted
Securities.
Securities held by the Fund may be legally restricted as to resale (such as those issued in private placements),
including commercial paper issued pursuant to Section 4(a)(2) of the 1933 Act, securities eligible for resale pursuant to Rule 144A thereunder,
and securities of U.S. and non-U.S. issuers initially offered and sold outside the United States pursuant to Regulation S thereunder.
Restricted securities may not be listed on an exchange and may have no active trading market. The Fund may incur additional expense when
disposing of restricted securities, including all or a portion of the cost to register the securities. The Fund also may acquire securities
through private placements under which it may agree to contractual restrictions on the resale of such securities that are in addition
to applicable legal restrictions. In addition, if the investment adviser and/or sub-adviser, if applicable, receives non-public information
about the issuer, the Fund may as a result be unable to sell the securities.

Restricted securities may be difficult to value properly and may involve
greater risks than securities that are not subject to restrictions on resale. It may be difficult to sell restricted securities at a price
representing fair value until such time as the securities may be sold publicly. Under adverse market or economic conditions or in the
event of adverse changes in the financial condition of the issuer, the Fund could find it more difficult to sell such securities when
the investment adviser and/or sub-adviser, if applicable, believes it advisable to do so or may be able to sell such securities only at
prices lower than if such securities were more widely held. Holdings of restricted securities may increase the level of Fund illiquidity
if eligible buyers become uninterested in purchasing them. Restricted securities may involve a high degree of business and financial risk,
which may result in substantial losses.

Fixed-Income
Securities and Other Debt Instruments.
  Fixed-income securities and other debt instruments include all types of fixed
and floating-rate bonds and notes, such as convertible securities and other hybrid securities (other than preferred stock); corporate
commercial paper; mortgage-backed and other asset-backed securities; inflation-indexed bonds issued by both governments and corporations;
structured notes, including “indexed” securities; loans; loan participations and assignments; delayed funding loans and revolving
credit facilities; and bank certificates of deposit, fixed time deposits, bank deposits (or investments structured to provide the same
type of exposure) and bankers’ acceptances of foreign and domestic banks and other debt instruments. Fixed-income securities and
other debt instruments are issued by: foreign governments or their subdivisions, agencies and government-sponsored enterprises; sovereign
entities; international agencies or supranational entities; the U.S. Government, its agencies or government-sponsored enterprises (or
guaranteed thereby); central or quasi-sovereign banks and U.S. and foreign corporations. Fixed-income securities and other debt instruments
include deep discount bonds, such as zero coupon bonds, deferred interest bonds, bonds or securities on which the interest is payable
in-kind (“PIK securities”), which are debt obligations that are issued at a significant discount from face value, and securities
purchased on a forward commitment or when-issued basis. While zero coupon bonds do not make periodic payments of interest, deferred interest
bonds provide for a period of delay before the regular payment of interest begins. PIK securities provide that the issuer thereof may,
at its option, pay interest in cash or in the form of additional securities.

Credit Risk.
Investments in debt instruments are subject to the risk of non-payment of scheduled principal and interest. Changes in economic conditions
or other circumstances may reduce the capacity of the party obligated to make principal and interest payments on such instruments and
may lead to defaults. Such non-payments and defaults may reduce the value of Fund shares and income distributions. The value of debt instruments
also may decline because of concerns about the issuer’s ability to make principal and interest payments. In addition, the credit
ratings of debt instruments may be lowered if the financial condition of the party obligated to make payments with respect to such instruments
deteriorates. In the event of bankruptcy of the issuer of a debt instrument, the Fund could experience delays or limitations with respect
to its ability to realize the benefits of any collateral securing the instrument. In order to enforce its rights in the event of a default,
bankruptcy or similar situation, the Fund may be required to retain legal or similar counsel, which may increase the Fund’s operating
expenses and adversely affect net asset value. The Fund is also exposed to credit risk when it engages in certain types of derivatives
transactions and when it engages in transactions that expose the Fund to counterparty risk. See “Derivatives.”

In evaluating the quality of a particular instrument, the investment
adviser (or sub-adviser, if applicable) may take into consideration, among other things, a credit rating assigned by a credit rating agency,
the issuer’s financial resources and operating history, its sensitivity to economic conditions and trends, the ability of its management,
its debt maturity schedules and borrowing requirements, and relative values based on anticipated cash flow, interest and asset coverage,

Calvert Mortgage Access Fund 12 Prospectus dated [______], 2022

and earnings prospects. Credit rating agencies are private services
that provide ratings of the credit quality of certain investments. Credit ratings issued by rating agencies are based on a number of factors
including, but not limited to, the issuer’s financial condition and the rating agency’s credit analysis, if applicable, at
the time of rating. As such, the rating assigned to any particular security is not necessarily a reflection of the issuer’s current
financial condition. The ratings assigned are not absolute standards of credit quality and do not evaluate market risks or necessarily
reflect the issuer’s current financial condition or the volatility or liquidity of the security.

For purposes of determining compliance with the Fund’s credit
quality restrictions, if any, the Fund’s investment adviser (or sub-adviser, if applicable) relies primarily on the ratings assigned
by credit rating agencies but may, in the case of unrated instruments, perform its own credit and investment analysis to determine an
instrument’s credit quality. A credit rating may have a modifier (such as plus, minus or a numerical modifier) to denote its relative
status within the rating. The presence of a modifier does not change the security credit rating (for example, BBB- and Baa3 are within
the investment grade rating) for purposes of the Fund’s investment limitations. If a security is rated differently by two or more
rating agencies, the highest rating will be used for any Fund rating restrictions.

Interest
Rate Risk.
In general, the value of income securities will fluctuate based on changes in interest rates. The value of these
securities is likely to increase when interest rates fall and decline when interest rates rise. Generally, securities with longer durations
or maturities are more sensitive to changes in interest rates than securities with shorter durations or maturities, causing them to be
more volatile. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns
than fixed-income securities with longer durations or maturities. In a rising interest rate environment, the duration of income securities
that have the ability to be prepaid or called by the issuer may be extended. In a declining interest rate environment, the proceeds from
prepaid or maturing instruments may have to be reinvested at a lower interest rate. The Fund may own individual investments that have
longer durations than the average duration of the Fund. The impact of interest rate changes on the value of floating rate instruments
is typically reduced by periodic interest rate resets. Variable and floating rate loans and securities generally are less sensitive to
interest rate changes, but may decline in value if their interest rates do not rise as much or as quickly as interest rates in general.
Conversely, variable and floating rate loans and securities generally will not increase in value as much as fixed rate debt instruments
if interest rates decline. Because the Fund holds variable and floating rate loans and securities, a decrease in market interest rates
will reduce the interest income to be received from such securities. In the event that the Fund has a negative average portfolio duration,
the value of the Fund may decline in a declining interest rate environment. Certain countries and regulatory bodies may use negative interest
rates as a monetary policy tool to encourage economic growth during periods of deflation. In a negative interest rate environment, debt
instruments may trade at negative yields, which means the purchaser of the instrument may receive at maturity less than the total amount
invested.

LIBOR.
The London Interbank Offered Rate or LIBOR is the average offered rate for various maturities of short-term loans between major international
banks who are members of the British Bankers Association. LIBOR is the most common benchmark interest rate index used to make adjustments
to variable-rate loans. It is used throughout global banking and financial industries to determine interest rates for a variety of financial
instruments (such as debt instruments and derivatives) and borrowing arrangements. In July 2017, the Financial Conduct Authority (the
“FCA”), the United Kingdom financial regulatory body, announced a desire to phase out the use of LIBOR. The ICE Benchmark
Administration Limited, the administrator of LIBOR ceased publishing certain LIBOR settings on December 31, 2021, and is expected to cease
publishing the remaining LIBOR settings on June 30, 2023. Many market participants are in the process of transitioning to the use of alternative
reference or benchmark rates.

Although the transition process away from LIBOR has become increasingly
well defined, the impact on certain debt securities, derivatives and other financial instruments
that utilize LIBOR remains uncertain. The transition process may involve, among other things, increased volatility or illiquidity in markets
for instruments that currently rely on LIBOR. The transition may also result in a change in (i) the value of certain instruments held
by the Fund, (ii) the cost of temporary borrowing for the Fund, or (iii) the effectiveness of related Fund transactions such as hedges,
as applicable.

Various financial industry groups are planning for the transition away
from LIBOR, but there are obstacles to converting certain longer term securities and transactions to a new benchmark. In June 2017, the
Alternative Reference Rates Committee, a group of large U.S. banks working with the Federal Reserve, announced its selection of a new
Secured Overnight Financing Rate (“SOFR”), which is intended to be a broad measure of secured overnight U.S. Treasury repo
rates, as an appropriate replacement for LIBOR. Bank working groups and regulators in other countries have suggested other alternatives
for their markets, including the Sterling Overnight Interbank Average Rate (“SONIA”) in England. Both SOFR and SONIA, as well
as certain other proposed replacement rates, are materially different from LIBOR, and changes in the applicable spread for financial instruments
transitioning away from LIBOR need to be made to accommodate the differences. Liquid markets for newly-issued instruments that use an
alternative reference rate are still developing. Consequently, there may be challenges for a Fund to enter into hedging transactions against
instruments tied to alternative reference rates until a market for such hedging transactions develops.

Calvert Mortgage Access Fund 13 Prospectus dated [______], 2022

Additionally, while some existing LIBOR-based instruments may contemplate
a scenario where LIBOR is no longer available by providing for an alternative or “fallback” rate-setting methodology, there
may be significant uncertainty regarding the effectiveness of any such alternative methodologies to replicate LIBOR. Not all existing
LIBOR-based instruments have such fallback provisions, and many that do, do not contemplate the permanent cessation of LIBOR. While it
is expected that market participants will amend legacy financial instruments referencing LIBOR to include fallback provisions to alternative
reference rates, there remains uncertainty regarding the willingness and ability of parties to add or amend such fallback provisions in
legacy instruments maturing after the end of 2021, particularly with respect to legacy cash products. Although there are ongoing efforts
among certain government entities and other organizations to address these uncertainties, the ultimate effectiveness of such efforts is
not yet known.

Any effects of the transition away from LIBOR and the adoption of
alternative reference rates, as well as other unforeseen effects, could result in losses to the Fund and such effects may occur prior to the
discontinuation of the remaining LIBOR settings in 2023. Furthermore, the risks associated with the discontinuation of LIBOR and transition to replacement rates
may be exacerbated if an orderly transition to an alternative reference rate is not completed in a timely manner.

Duration. 
Duration measures a fixed-income security’s price sensitivity to changes in the general level of interest rates. Duration differs
from maturity in that it considers a security’s coupon payments in addition to the amount of time until the security matures. As
the value of a security changes over time, so will its duration. Various techniques may be used to shorten or lengthen Fund duration.

Lower Rated
Investments.
Investments in obligations rated below investment grade and comparable unrated securities (sometimes referred
to as “junk”) generally entail greater economic, credit and liquidity risks than investment grade securities. Lower rated
investments have speculative characteristics because of the credit risk associated with their issuers. Changes in economic conditions
or other circumstances typically have a greater effect on the ability of issuers of lower rated investments to make principal and interest
payments than they do on issuers of higher rated investments. An economic downturn generally leads to a higher non-payment rate, and a
lower rated investment may lose significant value before a default occurs. Lower rated investments generally are subject to greater price
volatility and illiquidity than higher rated investments.

Because of the greater number of investment considerations involved
in investing in investments that receive lower ratings, investing in lower rated investments depends more on the investment adviser’s
judgment and analytical abilities than may be the case for investing in investments with higher ratings. While the investment adviser
will attempt to reduce the risks of investing in lower rated or unrated securities through, among other things, active portfolio management,
credit analysis and attention to current developments and trends in the economy and the financial markets, there can be no assurance that
the investment adviser will be successful in doing so.

Derivatives.
Generally, derivatives can be characterized as financial instruments whose performance is derived at least in part from the performance
of an underlying reference instrument. Derivative instruments may be acquired in the United States or abroad consistent with the Fund’s
investment strategy and may include the various types of exchange-traded and over-the-counter (“OTC”) instruments described
herein and other instruments with substantially similar characteristics and risks. Fund obligations created pursuant to derivative instruments
may give rise to leverage, which would subject the Fund to the requirements described under “Asset Coverage” in the Fund’s
SAI. The Fund may invest in a derivative transaction if it is permitted to own, invest in, or otherwise have economic exposure to the
reference instrument. Depending on the type of derivative instrument and the Fund’s investment strategy, a reference instrument
could be a security, instrument, index, currency, commodity, economic indicator or event (“reference instruments”). The Fund
may engage in derivative transactions to seek return, to hedge against fluctuations in securities prices, interest rates or currency exchange
rates, to change the duration of obligations held by the Fund, to manage certain investment risks or as a substitute for the purchase
or sale of securities or currencies. The Fund may trade in the specific type(s) and/or combinations of derivative transactions listed
below.

Derivative instruments are subject to a number of risks, including adverse
or unexpected movements in the price of the reference instrument, and counterparty, liquidity, market, tax and leverage risks. Certain
derivatives may also be subject to credit risk and interest rate risk. In addition, derivatives also involve the risk that changes in
their value may not correlate perfectly with the assets, rates, indices or instruments they are designed to hedge or closely track. Use
of derivative instruments may cause the realization of higher amounts of short-term capital gains (generally taxed at ordinary income
tax rates) than if such instruments had not been used. Success in using derivative instruments to hedge portfolio assets depends on the
degree of price correlation between the derivative instruments and the hedged asset. Imperfect correlation may be caused by several factors,
including temporary price disparities among the trading markets for the derivative instrument, the reference instrument and the Fund’s
assets. To the extent that a derivative instrument is intended to hedge against an event that does not occur, the Fund may realize losses.

Calvert Mortgage Access Fund 14 Prospectus dated [______], 2022

OTC derivative instruments involve an additional risk in that the issuer
or counterparty may fail to perform its contractual obligations. Some derivative instruments are not readily marketable or may become
illiquid under adverse market conditions. In addition, during periods of market volatility, an option or commodity exchange or swap execution
facility or clearinghouse may suspend or limit trading in an exchange-traded derivative instrument, which may make the contract temporarily
illiquid and difficult to price. Commodity exchanges may also establish daily limits on the amount that the price of a futures contract
or futures option can vary from the previous day’s settlement price. Once the daily limit is reached, no trades may be made that
day at a price beyond the limit. This may prevent the closing out of positions to limit losses. The ability to terminate OTC derivative
instruments may depend on the cooperation of the counterparties to such contracts. For thinly traded derivative instruments, the only
source of price quotations may be the selling dealer or counterparty. In addition, certain provisions of the Code limit the use of derivative
instruments. Derivatives permit the Fund to increase or decrease the level of risk, or change the character of the risk, to which its
portfolio is exposed in much the same way as the Fund can increase or decrease the level of risk, or change the character of the risk,
of its portfolio by making investments in specific securities. There can be no assurance that the use of derivative instruments will benefit
the Fund.

The U.S. and non-U.S. derivatives markets have undergone substantial
changes in recent years as a result of changes under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank
Act”) in the United States and regulatory changes in Europe, Asia and other non-U.S. jurisdictions. In particular, the Dodd-Frank
Act and related regulations require many derivatives to be cleared and traded on an exchange, expand entity registration requirements,
impose business conduct requirements on counterparties, and impose other regulatory requirements that will continue to change derivatives
markets as regulations are implemented. As of October 28, 2020, the SEC has adopted new regulations that may significantly alter a Fund’s
regulatory obligations with regard to its derivatives usage. In particular, the new regulations will, upon implementation, eliminate the
current asset segregation framework for covering derivatives and certain other financial instruments, impose new responsibilities on the
Board and establish new reporting and recordkeeping requirements for a Fund and may, depending on the extent to which a Fund uses derivatives,
impose value at risk limitations on a Fund’s use of derivatives, and require the Fund’s Board to adopt a derivative risk management
program. The implementation of these requirements may limit the ability of a Fund to use derivative instruments as part of its investment
strategy, increase the costs of using these instruments or make them less effective. Additional future regulation of the derivatives markets
may make the use of derivatives more costly, may limit the availability or reduce the liquidity of derivatives, and may impose limits
or restrictions on the counterparties with which the Fund engages in derivative transactions. Fund management cannot predict the effects
of any new governmental regulation that may be implemented, and there can be no assurance that any new government regulation will not
adversely affect the Fund’s performance or ability to achieve its investment objectives.

Options.
Options may be traded on an exchange and OTC. By buying a put option on a particular instrument, the Fund acquires a right to sell the
underlying instrument at the exercise price. By buying a put option on an index, the Fund acquires a right to receive the cash difference
between the strike price of the option and the index price at expiration. A purchased put position also typically can be sold at any time
by selling at prevailing market prices. Purchased put options generally are expected to limit the Fund’s risk of loss through a decline
in the market value of the underlying security or index until the put option expires. When buying a put option, the Fund pays a premium
to the seller of the option. If the price of the underlying security or index is above the exercise price of the option as of the option
valuation date, the option expires worthless and the Fund will not be able to recover the option premium paid to the seller. The Fund
may purchase uncovered put options on securities, meaning it will not own the securities underlying the option.

The Fund may also write (i.e., sell) put options. The Fund
will receive a premium for selling a put option, which may increase the Fund’s return. In selling a put option on a security, the Fund
has the obligation to buy the security at an agreed upon price if the price of such instrument decreases below the exercise price. By
selling a put option on an index, the Fund has an obligation to make a payment to the buyer to the extent that the value of the index
decreases below the exercise price as of the option valuation date. If the value of the underlying security or index on the option’s
expiration date is above the exercise price, the option will generally expire worthless and the Fund, as option seller, will have no obligation
to the option holder.

The Fund may purchase call options. By purchasing a call
option on a security, the Fund has the right to buy the security at the option’s exercise price. By buying a call option on an index,
the Fund acquires the right to receive the cash difference between the market price of the index and strike price at expiration. Call
options typically can be exercised any time prior to option maturity or, sold at the prevailing market price.

The Fund may also write (i.e., sell) a call option on a security
or index in return for a premium. A call written on a security obligates the Fund to deliver the underlying security at the option exercise
price. Written index call options obligate the Fund to make a cash payment to the buyer at expiration if the market price of the index
is above the option strike price. Calls typically can also be bought back by the Fund at prevailing market prices and the Fund also may
enter into closing purchase transactions with respect to written call options.

Calvert Mortgage Access Fund 15 Prospectus dated [______], 2022

The Fund’s options positions are marked to market daily.
The value of options is affected by changes in the value and dividend rates of their underlying instruments, changes in interest rates,
changes in the actual or perceived volatility of the relevant index or market and the remaining time to the options’ expiration,
as well as trading conditions in the options market. The hours of trading for options may not conform to the hours during which the underlying
instruments are traded. To the extent that the options markets close before markets for the underlying instruments, significant price
and rate movements can take place in the markets that would not be reflected concurrently in the options markets.

The Fund’s ability to sell the instrument underlying a call
option may be limited while the option is in effect unless the Fund enters into a closing purchase transaction. Uncovered call options
have speculative characteristics and are riskier than covered call options because there is no underlying instrument held by the Fund
that can act as a partial hedge. As the seller of a covered call option or an index call option, the Fund may forego, during the option’s
life, the opportunity to profit from increases in the market value of the underlying instrument covering the call option above the sum
of the premium received by the Fund and the exercise price of the call. The Fund also retains the risk of loss, minus the option premium
received, should the price of the underlying instrument decline.

Participants in OTC markets are typically not subject to
the same credit evaluation and regulatory oversight as are members of “exchange-based” markets. OTC option contracts generally
carry greater liquidity risk than exchange-traded contracts. This risk may be increased in times of financial stress, if the trading market
for OTC options becomes restricted. The ability of the Fund to transact business with any one or a number of counterparties may increase
the potential for losses to the Fund, due to the lack of any independent evaluation of the counterparties or their financial capabilities,
and the absence of a regulated market to facilitate settlement of the options.

Swaptions.
Swaptions are options giving the option owner the right (but not the obligation) to enter into a swap agreement as buyer or seller, or
to extend, shorten, cancel or otherwise modify an existing swap agreement at a future date on specified terms.

Depending on the terms of the particular swaption, the Fund
generally will incur a greater degree of risk when it writes a swaption than it will incur when it purchases a swaption. When the Fund
purchases a swaption, it risks losing only the amount of the premium it has paid should it decide to let the option expire unexercised.
When the Fund writes a swaption, upon exercise of the option, the Fund will become obligated according to the terms of the underlying
swap agreement.

Futures
Contracts.
Futures are standardized, exchange-traded contracts. Futures contracts on securities obligate a purchaser to take
delivery, and a seller to make delivery, of a specific amount of the financial instrument called for in the contract at a specified future
date at a specified price. An index futures contract obligates the purchaser to take, and a seller to deliver, an amount of cash equal
to a specific dollar amount times the difference between the value of a specific index at the close of the last trading day of the contract
and the price at which the agreement is made. No physical delivery of the underlying securities in the index is made. It is the practice
of holders of futures contracts to close out their positions on or before the expiration date by use of offsetting contract positions,
and physical delivery of financial instruments or delivery of cash, as applicable, is thereby avoided. An option on a futures contract
gives the holder the right to enter into a specified futures contract.

Forward
Foreign Currency Exchange Contracts.
A forward foreign currency exchange contract (“currency forward”) involves
an obligation to purchase or sell a specific currency at a future date, which may be any fixed number of days from the date of the contract
agreed upon by the parties, at a price set at the time of the contract. These contracts may be bought or sold to protect against an adverse
change in the relationship between currencies or to increase exposure to a particular foreign currency.

Certain currency forwards may be individually negotiated
and privately traded, exposing them to credit and counterparty risks. The precise matching of the currency forward amounts and the value
of the instruments denominated in the corresponding currencies will not generally be possible because the future value of such securities
in foreign currencies will change as a consequence of market movements in the value of those securities between the date on which the
contract is entered into and the date it matures. There is additional risk that the use of currency forwards may reduce or preclude the
opportunity for gain if the value of the currency should move in the direction opposite to the position taken and that currency forwards
may create exposure to currencies in which the Fund’s securities are not denominated. In addition, it may not be possible to hedge
against long-term currency changes. Currency forwards are subject to the risk of political and economic factors applicable to the countries
issuing the underlying currencies. Furthermore, unlike trading in most other types of instruments, there is no systematic reporting of
last sale information with respect to the foreign currencies underlying currency forwards. As a result, available information may not
be complete.

Interest
Rate Swaps.
 Interest rate swaps involve the exchange by the Fund with another party of their respective commitments to
pay or receive interest, e.g., an exchange of fixed rate payments for floating-rate payments.

Calvert Mortgage Access Fund 16 Prospectus dated [______], 2022

 

Credit
Default Swaps. 
Credit default swap agreements (“CDS”) enable the Fund to buy or sell credit protection on
an individual issuer or basket of issuers (i.e., the reference instrument). The Fund may enter into CDS to gain or short exposure to a
reference instrument. Long CDS positions are utilized to gain exposure to a reference instrument (similar to buying the instrument) and
are akin to selling insurance on the instrument. Short CDS positions are utilized to short exposure to a reference instrument (similar
to shorting the instrument) and are akin to buying insurance on the instrument.

Under a CDS, the protection “buyer” in a credit
default contract is generally obligated to pay the protection “seller” an upfront or a periodic stream of payments over the
term of the contract, provided that no credit event, such as a default, on a reference instrument has occurred. If a credit event occurs,
the seller generally must pay the buyer the “par value” (full notional value) of the reference instrument in exchange for
an equal face amount of the reference instrument described in the swap, or the seller may be required to deliver the related net cash
amount, if the swap is cash settled. If the Fund is a buyer and no credit event occurs, the Fund may recover nothing if the swap is held
through its termination date. As a seller, the Fund generally receives an upfront payment or a fixed rate of income throughout the term
of the swap provided that there is no credit event. The Fund’s obligations under a CDS will be accrued daily (offset against any
amounts owed to the Fund).

In response to market events, federal and certain state regulators
have proposed regulation of the CDS market. These regulations may limit the Fund’s ability to use CDS and/or the benefits of CDS.
CDS may be difficult to value and generally pay a return to the party that has paid the premium only in the event of an actual default
by the issuer of the underlying obligation (as opposed to a credit downgrade or other indication of financial difficulty). The Fund may
have difficulty, be unable or may incur additional costs to acquire any securities or instruments it is required to deliver under a CDS.
The Fund many have limited ability to eliminate its exposure under a CDS either by assignment or other disposition, or by entering into
an offsetting swap agreement. The Fund also may have limited ability to eliminate its exposure under a CDS if the reference instrument
has declined in value.

Inflation
Swaps.
Inflation swaps involve the exchange by the Fund with another party of their respective commitments to pay or receive
interest. This can involve an exchange of fixed rate payments for floating rate payments based on a reference index (an inflation index,
such as the Consumer Price Index) or an exchange of floating rate payments based on two different reference indices where one of the reference
indices is an inflation index. Inflation swaps can be designated as zero coupon, where both sides of the swap compound interest over the
life of the swap and then the accrued interest is paid in a lump sum at the swap’s maturity.

Credit
Linked Notes.
A credit linked note (“CLN”) is a type of hybrid instrument in which a special purpose entity issues
a structured note (the “note issuer”) with respect to which the reference instrument is a single bond, a portfolio of bonds
or the unsecured credit of an issuer, in general (each a “reference credit”). The purchaser of the CLN (the “note purchaser”)
invests a par amount and receives a payment during the term of the CLN that equals a fixed or floating rate of interest equivalent to
a high rated funded asset (such as a bank certificate of deposit) plus an additional premium that relates to taking on the credit risk
of the reference credit. Upon maturity of the CLN, the note purchaser will receive a payment equal to: (i) the original par amount paid
to the note issuer, if there is no occurrence of a designated event of default, restructuring or other credit event (each a “credit
event”) with respect to the issuer of the reference credit; or (ii) the market value of the reference credit, if a credit event
has occurred. Depending upon the terms of the CLN, it is also possible that the note purchaser may be required to take physical delivery
of the reference credit in the event of a credit event. Most CLNs use a corporate bond (or a portfolio of corporate bonds) as the reference
credit. However, almost any type of fixed-income security (including foreign government securities), index or derivative contract (such
as a credit default swap) can be used as the reference credit.

Forward
Rate Agreements.
  Under a forward rate agreement, the Fund locks in an interest rate at a future settlement date. If the
interest rate on the settlement date exceeds the lock rate, the Fund pays the seller the difference between the two rates. If the lock
rate exceeds the interest rate on the settlement date, the seller pays the Fund the difference between the two rates. Any such gain received
by the Fund would be taxable. These instruments are traded in the OTC market.

Total
Return Swaps. 
A total return swap is a contract in which one party agrees to make periodic payments to another party
based on the change in market value of a reference instrument during the specified period, in return for periodic payments from the other
party that are based on a fixed or variable interest rate or the total return of the reference instrument or another reference instrument.
Total return swap agreements may be used to obtain exposure to a security or market without owning or taking physical custody of such
security or investing directly in such market.

Counterparty
Risk.
A financial institution or other counterparty with whom the Fund does business (such as trading, securities lending
or as a derivatives counterparty), or that underwrites, distributes or guarantees any instruments that the Fund owns or is otherwise exposed
to, may decline in financial condition and become unable to honor its commitments. This could cause the value of Fund shares to decline
or could delay the return or delivery of collateral or other assets to the Fund. Counterparty risk is increased for contracts with longer
maturities.

Calvert Mortgage Access Fund 17 Prospectus dated [______], 2022

Foreign Investments.  Investments
in foreign issuers could be affected by factors not present in the United States, including expropriation, armed conflict, confiscatory
taxation, lack of uniform accounting and auditing standards, less publicly available financial and other information, and potential difficulties
in enforcing contractual obligations. Because foreign issuers may not be subject to uniform accounting, auditing and financial reporting
standard practices and requirements and regulatory measures comparable to those in the United States, there may be less publicly available
information about such foreign issuers. Settlements of securities transactions in foreign countries are subject to risk of loss, may be
delayed and are generally less frequent than in the United States, which could affect the liquidity of the Fund’s assets. Evidence
of ownership of certain foreign investments may be held outside the United States, and the Fund may be subject to the risks associated
with the holding of such property overseas. Trading in certain foreign markets is also subject to liquidity risk.

Foreign investment in the securities markets of certain foreign countries
is restricted or controlled to varying degrees. Foreign issuers may become subject to sanctions imposed by the United States or another
country, which could result in the immediate freeze of the foreign issuers’ assets or securities. The imposition of such sanctions
could impair the market value of the securities of such foreign issuers and limit the Fund’s ability to buy, sell, receive or deliver
the securities. In addition, as a result of economic sanctions, the Fund may be forced to sell or otherwise dispose of investments at
inopportune times or prices, which could result in losses to the Fund and increased transaction costs. If a deterioration occurs in a
country’s balance of payments, the country could impose temporary restrictions on foreign capital remittances. The Fund could also be
adversely affected by delays in, or a refusal to grant, any required governmental approval for repatriation, as well as by other restrictions
on investment. The risks posed by such actions with respect to a particular foreign country, its nationals or industries or businesses
within the country may be heightened to the extent the Fund invests significantly in the affected country or region or in issuers from
the affected country that depend on global markets.

Political events in foreign countries may cause market disruptions.
In June 2016, the United Kingdom (“UK”) voted in a referendum to leave the European Union (“EU”) (“Brexit”).
Effective January 31, 2020, the UK ceased to be a member of the EU and, following a transition period during which the EU and the UK Government
engaged in a series of negotiations regarding the terms of the UK’s future relationship with the EU, the EU and the UK Government
signed an agreement on December 30, 2020 regarding the economic relationship between the UK and the EU. This agreement became effective
on a provisional basis on January 1, 2021 and entered into full force on May 1, 2021. There remains significant market uncertainty regarding
Brexit’s ramifications, and the range and potential implications of the possible political, regulatory, economic, and market outcomes
in the UK, EU and beyond are difficult to predict. The end of the Brexit transition period may cause greater market volatility and illiquidity,
currency fluctuations, deterioration in economic activity, a decrease in business confidence, and an increased likelihood of a recession
in the UK. If one or more additional countries leave the EU or the EU dissolves, the world’s securities markets likely will be significantly
disrupted.

Foreign Currencies.
The value of foreign assets and currencies as measured in U.S. dollars may be affected favorably or unfavorably by changes
in foreign currency rates and exchange control regulations, application of foreign tax laws (including withholding tax), governmental
administration of economic or monetary policies (in this country or abroad), and relations between nations and trading. Foreign currencies
also are subject to settlement, custodial and other operational risks. Currency exchange rates can be affected unpredictably by intervention,
or the failure to intervene, by U.S. or foreign governments or central banks or by currency controls or political developments in the
United States or abroad. If the U.S. dollar rises in value relative to a foreign currency, a security denominated in that foreign currency
will be worth less in U.S. dollars. If the U.S. dollar decreases in value relative to a foreign currency, a security denominated in that
foreign currency will be worth more in U.S. dollars. A devaluation of a currency by a country’s government or banking authority
will have a significant impact on the value of any investments denominated in that currency. Costs are incurred in connection with conversions
between currencies.

Forward Commitments
and When-Issued Securities.
The Fund may purchase securities on a “forward commitment” or “when-issued”
basis (meaning securities are purchased or sold with payment and delivery taking place in the future). In such a transaction, the Fund
is securing what is considered to be an advantageous price and yield at the time of entering into the transaction.

The yield on a comparable security when the transaction is consummated
may vary from the yield on the security at the time that the forward commitment or when-issued transaction was made. From the time of
entering into the transaction until delivery and payment is made at a later date, the securities that are the subject of the transaction
are subject to market fluctuations. In forward commitment or when-issued transactions, if the seller or buyer, as the case may be, fails
to consummate the transaction, the counterparty may miss the opportunity of obtaining a price or yield considered to be advantageous.
Forward commitment or when-issued transactions may be expected to occur a month or more before delivery is due. No payment or delivery
is made, however, until payment is received or delivery is made from the other party to the transaction. These transactions may create
leverage in the Fund.

Calvert Mortgage Access Fund 18 Prospectus dated [______], 2022

 

Short Sales.
The Fund may engage in short sales on securities or a basket or index of securities. A short sale on an individual security typically
involves the sale of a security that is borrowed from a broker or other institution to complete the sale. When making a short sale, the
Fund must segregate liquid assets with a broker or the custodian equal to (or otherwise cover) its obligations under the short sale. Generally,
securities held in a segregated account cannot be sold unless they are replaced with other liquid assets. This may limit the Fund’s
investment flexibility, as well as its ability to meet redemption requests or other current obligations. The seller of a short position
generally realizes a profit from the transaction if the proceeds it receives on the short sale exceed the cost of purchasing the securities
sold short in the market, but will generally realize a loss if the cost of closing the short position exceeds the proceeds from the short
sale. The Fund pays interest or dividend expense with respect to securities sold short.

If the Fund does not own the securities sold short, the short sale exposes
the Fund to the risk that it will be required to purchase securities to replace the borrowed securities (also known as “covering”
the short position) at a time when the securities sold short have appreciated in value, thus resulting in a loss. There is no assurance
that a security sold short will decline in value or make a profit for the Fund. In addition, there is no guarantee that any security needed
to cover the short position will be available for purchase. Short selling carries a risk that the counterparty to the short sale may fail
to honor its contract terms, causing a loss to the Fund. Further, if other short positions of the same security are closed out at the
same time, a “short squeeze” can occur where demand exceeds the supply for the security sold short. A short squeeze makes
it more likely that the Fund will need to replace the borrowed security at an unfavorable price. If the Fund invests the proceeds received
for selling securities short in other investments, the Fund is employing a form of leverage.

Loans.
 Loans may be primary, direct investments or investments in loan assignments or participation interests. A loan assignment represents
a portion or the entirety of a loan and a portion or the entirety of a position previously attributable to a different lender. The purchaser
of an assignment typically succeeds to all the rights and obligations under the loan agreement and has the same rights and obligations
as the assigning investor. However, assignments through private negotiations may cause the purchaser of an assignment to have different
and more limited rights than those held by the assigning investor. Loan participation interests are interests issued by a lender or other
entity and represent a fractional interest in a loan. The Fund typically will have a contractual relationship only with the financial
institution that issued the participation interest. As a result, the Fund may have the right to receive payments of principal, interest
and any fees to which it is entitled only from the financial institution and only upon receipt by such entity of such payments from the
borrower. In connection with purchasing a participation interest, the Fund generally will have no right to enforce compliance by the borrower
with the terms of the loan agreement, nor any rights with respect to any funds acquired by other investors through set-off against the
borrower and the Fund may not directly benefit from the collateral supporting the loan in which it has purchased the participation interest.
As a result, the Fund may assume the credit risk of both the borrower and the financial institution issuing the participation interest.
In the event of the insolvency of the entity issuing a participation interest, the Fund may be treated as a general creditor of such entity.
Most loans are rated below investment grade or, if unrated, are of similar credit quality.

Loan investments may be made at par or at a discount or premium to par.
The interest payable on a loan may be fixed or floating rate, and paid in cash or in-kind. In connection with transactions in loans, the
Fund may be subject to facility or other fees. Loans may be secured by specific collateral or other assets of the borrower, guaranteed
by a third party, unsecured or subordinated. During the term of a loan, the value of any collateral securing the loan may decline in value,
causing the loan to be under collateralized. Collateral may consist of assets that may not be readily liquidated, and there is no assurance
that the liquidation of such assets would satisfy fully a borrower’s obligations under the loan. In addition, if a loan is foreclosed,
the Fund could become part owner of the collateral and would bear the costs and liabilities associated with owning and disposing of such
collateral.

Certain loans (“senior loans”) hold a senior position in
the capital structure of a business entity, are typically secured with specific collateral and have a claim on the assets and/or stock
of the borrower that is senior to that held by subordinated debtholders and stockholders of the borrower. Junior loans may be secured
or unsecured subordinated loans, second lien loans and subordinated bridge loans. Floating-rate loans typically have rates of interest
which are re-determined daily, monthly, quarterly or semi-annually by reference to a base lending rate, plus a premium.

A lender’s repayment and other rights primarily are
determined by governing loan, assignment or participation documents, which (among other things) typically establish the priority of
payment on the loan relative to other indebtedness and obligations of the borrower. A borrower typically is required to comply with
certain covenants contained in a loan agreement between the borrower and the holders of the loan. The types of covenants included in
loan agreements generally vary depending on market conditions, the creditworthiness of the issuer, and the nature of the collateral
securing the loan. Loans with fewer covenants that restrict activities of the borrower may provide the borrower with more
flexibility to take actions that may be detrimental to the loan holders and provide fewer investor protections in the event
covenants are breached. The Fund may experience relatively greater realized or unrealized losses or delays and expense in enforcing
its rights with respect to loans with fewer restrictive covenants. Loans to entities located outside of the U.S. may have
substantially different lender protections and covenants as compared to loans to U.S. entities and may involve greater risks. 
In the event of bankruptcy, applicable law may impact a lender’s ability to enforce its rights. Bankruptcy laws in foreign
jurisdictions, including emerging markets, may differ significantly from U.S. bankruptcy law and the Fund’s rights with
respect to a loan governed by the laws of a foreign jurisdiction may be more limited.

Calvert Mortgage Access Fund 19 Prospectus dated [______], 2022

Loans may be originated by a lending agent, such as a financial institution
or other entity, on behalf of a group or “syndicate” of loan investors (the “Loan Investors”). In such a case,
the agent administers the terms of the loan agreement and is responsible for the collection of principal, and interest payments from the
borrower and the apportionment of these payments to the Loan Investors. Failure by the agent to fulfill its obligations may delay or adversely
affect receipt of payment by the Fund. Furthermore, unless under the terms of a loan agreement or participation (as applicable) the Fund
has direct recourse against the borrower, the Fund must rely on the agent and the other Loan Investors to pursue appropriate remedies
against the borrower.

Although the overall size and number of participants in the market for
many loans has grown over the past decade, such loans continue to trade in a private, unregulated inter-dealer or inter-bank secondary
market and the amount of available public information about loans may be less extensive than that available for registered or exchange
listed securities. With limited exceptions, the investment adviser will take steps intended to insure that it does not receive material
nonpublic information about the issuers of loans that also issue publicly traded securities. Therefore, the investment adviser may have
less information than other investors about certain of the loans in which it seeks to invest. Purchases and sales of loans are generally
subject to contractual restrictions that must be satisfied before a loan can be bought or sold.  These restrictions may (i) impede
the Fund’s ability to buy or sell loans, (ii) negatively impact the transaction price, (iii) impact the counterparty and/or credit
risks borne by the Fund, (iv) impede the Fund’s ability to timely vote or otherwise act with respect to loans, (v) expose the Fund
to adverse tax or regulatory consequences and/or (vi) result in delayed settlement of loan transactions. It may take longer than seven
days for a transaction in loans to settle, which may impact the Fund’s process for meeting redemptions. See “Liquidity Risk.”
This is partly due to the nature of manner in which loans trade and the contractual restrictions noted above, which require a written
assignment agreement and various ancillary documents for each transfer, and frequently require discretionary consents from both the borrower
and the administrative agent.  In light of the foregoing, the Fund may hold cash, sell investments or temporarily borrow to meet
its cash needs, including satisfying redemption requests.

Assignments of loans through private negotiations may cause the purchaser
of an assignment to have different and more limited rights than those held by the assigning investor. In connection with purchasing a
participation interest, the Fund generally will have no right to enforce compliance by the borrower with the terms of the loan agreement.
In the event the borrower defaults, the Fund may not directly benefit from the collateral supporting the loan (if any) in which it has
purchased the participation interest. As a result, the Fund may assume the credit risk of both the borrower and the financial institution
issuing the participation interest. No active trading market may exist for certain loans, which may impair the ability of the Fund to
realize full value in the event of the need to sell a loan and which may make it difficult to value the loan. To the extent that a secondary
market does exist for certain loans, the market may be subject to irregular trading activity, wide bid/ask spreads and extended trade
settlement periods.

In addition to the risks generally associated with debt instruments,
such as credit, market, interest rate and liquidity risks, loans are also subject to the risk that the value of any collateral securing
a loan may decline, be insufficient to meet the obligations of the borrower or be difficult to liquidate. The specific collateral used
to secure a loan may decline in value or become illiquid, which would adversely affect the loan’s value. The Fund’s access
to collateral may be limited by bankruptcy, other insolvency laws or by the type of loan the Fund has purchased. For example, if the Fund
purchases a participation instead of an assignment, it would not have direct access to collateral of the borrower. As a result, a floating-rate
loan may not be fully collateralized and can decline significantly in value. Additionally, collateral on loan instruments may not be readily
liquidated, and there is no assurance that the liquidation of such assets will satisfy a borrower’s obligations under the investment.

Loans are subject to the risk that a court, pursuant to fraudulent conveyance
or other similar laws, could subordinate a loan to presently existing or future indebtedness of the borrower, or take other action detrimental
to the holders of a loan including, in certain circumstances, invalidating a loan or causing interest previously paid to be refunded to
the borrower. Any such actions by a court could negatively affect the Fund’s performance. Loans that are secured and senior to other
debtholders of a borrower tend to have more favorable loss recovery rates as compared to more junior types of below investment grade debt
obligations. Due to their lower place in the borrower’s capital structure and, in some cases, their unsecured status, junior loans
involve a higher degree of overall risk than senior loans of the same borrower.

Investing in loans involves the risk of default by the borrower or other
party obligated to repay the loan. In the event of insolvency of the borrower or other obligated party, the Fund may be treated as a general
creditor of such entity unless it has rights that are senior to that of other creditors or secured by specific collateral or assets of
the borrower. Fixed rate loans are also subject to the risk that their value will decline in a rising interest rate environment. This
risk is mitigated for floating-rate loans, where the interest rate payable on the loan resets periodically by reference to a base lending
rate.

Calvert Mortgage Access Fund 20 Prospectus dated [______], 2022

U.S. federal securities laws afford certain protections against fraud
and misrepresentation in connection with the offering or sale of a security, as well as against manipulation of trading markets for securities.
The typical practice of a lender in relying exclusively or primarily on reports from the borrower may involve the risk of fraud, misrepresentation,
or market manipulation by the borrower. It is unclear whether U.S. federal securities law protections are available to an investment in
a loan. In certain circumstances, loans may not be deemed to be securities, and in the event of fraud or misrepresentation by a borrower,
lenders may not have the protection of the anti-fraud provisions of the federal securities laws. However, contractual provisions in the
loan documents may offer some protections, and lenders may also avail themselves of common-law fraud protections under applicable state
law.

Inflation-Indexed
Bonds.
Inflation-indexed bonds (other than municipal inflation-indexed bonds and certain corporate inflation-indexed bonds)
are fixed-income securities whose principal value is periodically adjusted according to the rate of inflation. The principal amount of
an inflation-indexed bond is adjusted in response to changes in the level of inflation. Repayment of the original bond principal upon
maturity (as adjusted for inflation) is guaranteed in the case of U.S. Treasury inflation-indexed bonds, and therefore, the principal
amount of such bonds cannot be reduced below par even during a period of deflation. However, the current market value of these bonds is
not guaranteed and will fluctuate, reflecting the risk of changes in their yields. In certain jurisdictions outside the United States,
the repayment of the original bond principal upon the maturity of an inflation-indexed bond is not guaranteed, allowing for the amount
of the bond repaid at maturity to be less than par. The interest rate for inflation-indexed bonds is fixed at issuance as a percentage
of this adjustable principal. Accordingly, the actual interest income may both rise and fall as the principal amount of the bonds adjusts
in response to movements in the Consumer Price Index, a measure of inflation.

The value of inflation-indexed bonds is expected to change in response
to changes in real interest rates (i.e. the rate of interest after allowing for inflation). If the index measuring inflation falls, the
principal value of inflation-indexed bonds (other than municipal inflation-indexed bonds and certain corporate inflation-indexed bonds)
will be adjusted downward, and consequently the interest payable on these securities (calculated with respect to a smaller principal amount)
will be reduced. Repayment of the original bond principal upon maturity (as adjusted for inflation) is guaranteed by the U.S. Treasury
in the case of U.S. Treasury inflation-indexed bonds. For bonds that do not provide a similar guarantee, the adjusted principal value
of the bond repaid at maturity may be less than the original principal. While these securities are expected to be protected from long-term
inflationary trends, short-term increases in inflation may lead to a decline in value. If interest rates rise due to reasons other than
inflation (for example, due to changes in currency exchange rates), investors in these securities may not be protected to the extent that
the increase is not reflected in the bond’s inflation measure.

Repurchase
Agreements.
 A repurchase agreement is the purchase by the Fund of securities from a counterparty in exchange for cash
that is coupled with an agreement to resell those securities to the counterparty at a specified date and price. Repurchase agreements
maturing in more than seven days that the investment adviser believes may not be terminated within seven days at approximately the amount
at which the Fund has valued the agreements are considered illiquid securities. When a repurchase agreement is entered into, the Fund
typically receives securities with a value that equals or exceeds the repurchase price, including any accrued interest earned on the agreement.
The value of such securities will be marked to market daily, and cash or additional securities will be exchanged between the parties as
needed. Except in the case of a repurchase agreement entered into to settle a short sale, the value of the securities delivered to the
Fund will be at least equal to 90% of such repurchase price during the term of the repurchase agreement. The terms of a repurchase agreement
entered into to settle a short sale may provide that the cash purchase price paid by the Fund is more than the value of purchased securities
that effectively collateralize the repurchase price payable by the counterparty. Since in such a transaction the Fund normally will have
used the purchased securities to settle the short sale, the Fund will segregate liquid assets equal to the marked to market value of the
purchased securities that it is obligated to return to the counterparty under the repurchase agreement.

In the event of the insolvency of the counterparty to a repurchase agreement,
recovery of the repurchase price owed to the Fund may be delayed. In a repurchase agreement, such an insolvency may result in a loss to
the extent that the value of the purchased securities decreases during the delay or that value has otherwise not been maintained at an
amount equal to the repurchase price. Repurchase agreements may create leverage in the Fund.

Reverse Repurchase
Agreements.
The Fund may enter into reverse repurchase agreements. Under a reverse repurchase agreement, the Fund transfers
possession of a security to a counterparty, such as a bank or broker-dealer, in return for cash. At the same time, the Fund agrees to
repurchase the security at an agreed upon time and price, which reflects an interest payment. The Fund may enter into such agreements
when it believes it is able to invest the cash acquired at a rate higher than the cost of the agreement, which would increase the Fund’s
earned income. The Fund may also enter into reverse repurchase agreements as a means of raising cash to satisfy redemption requests without
the necessity of selling portfolio holdings.

Calvert Mortgage Access Fund 21 Prospectus dated [______], 2022

 

In the event of the insolvency of the counterparty to a reverse repurchase
agreement, recovery of the securities sold by the Fund may be delayed. In a reverse repurchase agreement, the counterparty’s insolvency
may result in a loss equal to the amount by which the value of the securities sold by the Fund exceeds the repurchase price payable by
the Fund. When the Fund enters into a reverse repurchase agreement, any fluctuations in the market value of either the securities sold
to the counterparty or the securities which the Fund purchases with the proceeds under the agreement would affect the value of the Fund’s
assets. As a result, such agreements may increase fluctuations in the net asset value of the Fund’s shares. Because reverse repurchase
agreements are considered to be a form of borrowing by the Fund (and a loan from the counterparty), they constitute leverage.

Cash 
and Money Market Instruments. The Fund may invest in cash or money
market instruments, including high quality short-term instruments or an affiliated investment company that invests in such instruments.
During unusual market conditions, the Fund may invest up to 100% of its assets in cash or money market instruments temporarily, which
may be inconsistent with its investment objective(s) and other policies.

Money market instruments may be adversely affected by market and economic
events, such as a sharp rise in prevailing short-term interest rates; adverse developments in the banking industry, which issues or guarantees
many money market instruments; adverse economic, political or other developments affecting issuers of money market instruments; changes
in the credit quality of issuers; and default by a counterparty.

Pooled Investment
Vehicles.
The Fund may invest in pooled investment vehicles to the extent permitted by the 1940 Act, and the rules, regulations
and interpretations thereunder. Pooled investment vehicles are open- and closed-end investment companies unaffiliated with the investment
adviser, open-end investment companies affiliated with the investment adviser and exchange-traded funds (“ETFs”). Pooled investment
vehicles are subject to the risks of investing in the underlying securities or other instruments that they own. The market for common
shares of closed-end investment companies and ETFs, which are generally traded on an exchange and may be traded at a premium or discount
to net asset value, is affected by the demand for those securities, regardless of the value of such fund’s underlying securities.
Additionally, natural or environmental disasters, widespread disease or other public health issues, war, acts of terrorism or other events
could result in increased premiums or discounts to such fund’s net asset value. The Fund will indirectly bear its proportionate
share of any management fees and other operating expenses paid by unaffiliated and certain affiliated pooled investment vehicles in which
it invests. If such fees exceed 0.01%, the costs associated with such investments will be reflected under Acquired Fund Fees and Expenses
in the Fund’s Annual Fund Operating Expenses table(s) in its Fund Summary.

Borrowing. 
The Fund is permitted to borrow for temporary purposes (such as to satisfy redemption requests, to remain fully invested in anticipation
of expected cash inflows and to settle transactions). Any borrowings by the Fund are subject to the requirements of the 1940 Act. Borrowings
are also subject to the terms of any credit agreement between the Fund and lender(s). Fund borrowings may be equal to as much as 331/3%
of the value of the Fund’s total assets (including such borrowings) less the Fund’s liabilities (other than borrowings). The
Fund will not purchase additional investments while outstanding borrowings exceed 5% of the value of its total assets. In addition, the
Fund is authorized to borrow to acquire additional investments when the investment adviser believes that the interest payments and other
costs with respect to such borrowings will be exceeded by the anticipated total return on such investments. There is no assurance that
a borrowing strategy will be successful.

In addition, the Fund will be required to maintain a specified level
of asset coverage with respect to all borrowings and may be required to sell some of its holdings to reduce debt and restore coverage
at times when it may not be advantageous to do so. The rights of the lender to receive payments of interest and repayments of principal
of any borrowings made by the Fund under a credit facility are senior to the rights of holders of shares with respect to the payment of
dividends or upon liquidation. In the event of a default under a credit arrangement, the lenders may have the right to cause a liquidation
of the collateral (i.e., sell Fund assets) and, if any such default is not cured, the lenders may be able to control the liquidation as
well.

Leverage.
Certain types of Fund transactions may give rise to economic leverage, which represents a non-cash exposure to the underlying reference
instrument. Leverage can increase both the risk and return potential of the Fund.

The Fund is required to segregate liquid assets or otherwise cover the
Fund’s obligation created by a transaction that may give rise to leverage. The use of leverage may cause the Fund to liquidate portfolio
positions when it may not be advantageous to do so to satisfy its obligations or to meet segregation requirements. Leverage may cause
the Fund’s share price to be more volatile than if it had not been leveraged, as certain types of leverage may exaggerate the effect
of any increase or decrease in the value of the Fund’s portfolio securities. The loss on leveraged investments may substantially
exceed the initial investment.

Calvert Mortgage Access Fund 22 Prospectus dated [______], 2022

 

Research
Process.  
The Fund’s portfolio management utilizes information provided by, and the expertise of, the research
staff of the investment adviser and/or certain of its affiliates in making investment decisions. As part of the research process, portfolio
management may consider financially material environmental, social and governance (“ESG”) factors. Such factors, alongside
other relevant factors, may be taken into account in the Fund’s securities selection process.

Securities
Lending.
The Fund may lend its portfolio securities to broker-dealers and other institutional borrowers. During the existence
of a loan, the Fund will continue to receive the equivalent of the interest paid by the issuer on the securities loaned, or all or a portion
of the interest on investment of the collateral, if any. The Fund may pay lending fees to such borrowers. Loans will only be made to firms
that have been approved by the investment adviser, and the investment adviser or the securities lending agent will periodically monitor
the financial condition of such firms while such loans are outstanding. Securities loans will only be made when the investment adviser
believes that the expected returns, net of expenses, justify the attendant risks. Securities loans currently are required to be secured
continuously by collateral in cash, cash equivalents (such as money market instruments) or other liquid securities held by the custodian
and maintained in an amount at least equal to the market value of the securities loaned. The Fund may engage in securities lending to
generate income. Upon return of the loaned securities, the Fund would be required to return the related collateral to the borrower and
may be required to liquidate portfolio securities in order to do so. The Fund may lend up to one-third of the value of its total assets
or such other amount as may be permitted by law.

As with other extensions of credit, there are risks of delay in recovery
or even loss of rights in the securities loaned if the borrower of the securities fails financially. To the extent that the portfolio
securities acquired with such collateral have decreased in value, it may result in the Fund realizing a loss at a time when it would not
otherwise do so. As such, securities lending may introduce leverage into the Fund. The Fund also may incur losses if the returns on securities
that it acquires with cash collateral are less than the applicable rebate rates paid to borrowers and related administrative costs.

Converting
to Hub and Spoke Structure.
 The Fund may invest all of its investable assets in an open-end management investment company
(“portfolio”) with substantially the same investment objective, policies and restrictions as the Fund. Any such portfolio
would be advised by the Fund’s investment adviser (or an affiliate) and the Fund would not pay directly any advisory fee with respect
to the assets so invested. The Fund may initiate investments in a portfolio at any time without shareholder approval.

Cybersecurity
Risk.
With the increased use of technologies by Fund service providers to conduct business, such as the Internet, the Fund
is susceptible to operational, information security and related risks. The Fund relies on communications technology, systems, and networks
to engage with clients, employees, accounts, shareholders, and service providers, and a cyber incident may inhibit the Fund’s ability
to use these technologies. In general, cyber incidents can result from deliberate attacks or unintentional events. Cyber attacks include,
but are not limited to, gaining unauthorized access to digital systems (e.g., through “hacking” or malicious software coding)
for purposes of misappropriating assets or sensitive information, corrupting data, or causing operational disruption. Cyber attacks may
also be carried out in a manner that does not require gaining unauthorized access, such as causing denial-of-service attacks on websites.
A denial-of-service attack is an effort to make network services unavailable to intended users, which could cause shareholders to lose
access to their electronic accounts, potentially indefinitely. Employees and service providers also may not be able to access electronic
systems to perform critical duties for the Fund, such as trading and NAV calculation, during a denial-of-service attack. There is also
the possibility for systems failures due to malfunctions, user error and misconduct by employees and agents, natural disasters, or other
foreseeable and unforeseeable events.

Because technology is consistently changing, new ways to carry out cyber
attacks are always developing. Therefore, there is a chance that some risks have not been identified or prepared for, or that an attack
may not be detected, which puts limitations on the Fund’s ability to plan for or respond to a cyber attack. Like other funds and business
enterprises, the Fund and its service providers have experienced, and will continue to experience, cyber incidents consistently. In addition
to deliberate cyber attacks, unintentional cyber incidents can occur, such as the inadvertent release of confidential information by the
Fund or its service providers.

The Fund uses third party service providers who are also heavily dependent
on computers and technology for their operations. Cybersecurity failures by or breaches of the Fund’s investment adviser or administrator
and other service providers (including, but not limited to, the custodian or transfer agent), and the issuers of securities in which the
Fund invests, may disrupt and otherwise adversely affect their business operations. This may result in financial losses to the Fund, impede
Fund trading, interfere with the Fund’s ability to calculate its NAV, limit a shareholder’s ability to purchase or redeem
shares of the Fund or cause violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, reimbursement
or other compensation costs, litigation costs, or additional compliance costs. While many of the Fund’s service providers have established
business continuity plans and risk management systems intended to identify and mitigate cyber attacks, there are inherent limitations
in such plans and systems, including the possibility that certain risks have not been identified. The Fund cannot control the cybersecurity
plans and systems put in place by service providers to the Fund and issuers in which the Fund invests. The Fund and its shareholders could
be negatively impacted as a result.

Calvert Mortgage Access Fund 23 Prospectus dated [______], 2022

Recent Market
Conditions. 
An outbreak of respiratory disease caused by a novel coronavirus was first detected in China in late 2019
and subsequently spread internationally. This coronavirus has resulted in closing borders, enhanced health screenings, changes to healthcare
service preparation and delivery, quarantines, cancellations, disruptions to supply chains and customer activity, as well as general concern
and uncertainty. The impact of this coronavirus has resulted in a substantial economic downturn, which may continue for an extended period
of time. Health crises caused by outbreaks of disease, such as the coronavirus outbreak, may exacerbate other pre-existing political,
social and economic risks and disrupt normal market conditions and operations. The impact of this outbreak has negatively affected the
worldwide economy, as well as the economies of individual countries and industries, and could continue to affect the market in significant
and unforeseen ways. Other epidemics and pandemics that may arise in the future may have similar effects. For example, a global pandemic
or other widespread health crisis could cause substantial market volatility and exchange trading suspensions and closures. In addition,
the increasing interconnectedness of markets around the world may result in many markets being affected by events or conditions in a single
country or region or events affecting a single or small number of issuers. The coronavirus outbreak and public and private sector responses
thereto have led to large portions of the populations of many countries working from home for indefinite periods of time, temporary or
permanent layoffs, disruptions in supply chains, and lack of availability of certain goods. The impact of such responses could adversely
affect the information technology and operational systems upon which the Fund and the Fund’s service providers rely, and could otherwise
disrupt the ability of the employees of the Fund’s service providers to perform critical tasks relating to the Fund. Any such impact
could adversely affect the Fund’s performance, or the performance of the securities in which the Fund invests and may lead to losses
on your investment in the Fund.

General.  Unless
otherwise stated, the Fund’s investment objective(s) and certain other policies may be changed without shareholder approval. The Fund
might not use all of the strategies and techniques or invest in all of the types of securities described in this Prospectus or the SAI.
While at times the Fund may use alternative investment strategies in an effort to limit its losses, it may choose not to do so.

The Fund’s annual operating expenses are expressed as a percentage
of the Fund’s average daily net assets and may change as Fund assets increase and decrease over time. Purchase and redemption activities
by Fund shareholders may impact the management of the Fund and its ability to achieve its investment objective. In addition, the redemption
by one or more large shareholders or groups of shareholders of their holdings in the Fund could have an adverse impact on the remaining
shareholders in the Fund. Mutual funds, investment advisers, other market participants and many securities markets are subject to rules
and regulations and the jurisdiction of one or more regulators.  Changes to applicable rules and regulations or to widely accepted
market conventions or standards could have an adverse effect on securities markets and market participants, as well as on the Fund’s
ability to execute its investment strategy. With the increased use of technologies by Fund service providers, such as the Internet, to
conduct business, the Fund is susceptible to operational, information security and related risks. See “Additional Information about
Investment Strategies and Risks” in the Fund’s SAI.

About Responsible Investing

Investment Selection Process

CRM seeks to invest in issuers that manage ESG risk exposures adequately
and that are not exposed to excessive ESG risk through their principal business activities. Issuers are analyzed using The Calvert Principles
for Responsible Investment (included as Appendix A to this Prospectus), a framework for considering ESG factors. Each issuer is evaluated
relative to an appropriate peer group based on financially material ESG factors as determined by CRM. CRM’s evaluation of a particular
security’s responsible investing characteristics generally involves both quantitative and qualitative analysis. In assessing investments,
CRM generally focuses on the ESG factors relevant to the issuer’s operations, and an issuer may be acceptable for investment based
primarily on such assessment. Securities may be deemed suitable for investment even if the issuer does not operate in accordance with
all elements of the Fund’s responsible investing criteria. The Fund may also invest in issuers that CRM believes are likely to operate
in accordance with the Principles pending CRM’s engagement activity with such issuer. In assessing issuers for which quantitative
data is limited, subjective judgments may serve as the primary basis for CRM’s evaluation. The responsible investing criteria of
a Fund may be changed by the Board without shareholder approval.

As described above, or in the SAI, the Fund may invest in cash, money
market instruments and ETFs. Such investments will generally not be subject to responsible investment analysis and will not be required
to be consistent with the responsible investment criteria otherwise applicable to investments made by the Fund, unless the Fund invests
in an affiliated investment company that invests in high quality short-term instruments, and in selecting such investments, is guided
by The Calvert Principles for Responsible Investment. In addition, ETFs in which the Fund may invest may hold securities of issuers that
do not operate in accordance with the Fund’s responsible investment criteria.

Calvert Mortgage Access Fund 24 Prospectus dated [______], 2022

 

High Social
Impact Investments.
  Up to 3% of the Fund’s net assets may be invested in High Social Impact Investments. High Social
Impact Investments are investments that, in the Adviser’s opinion, offer the opportunity for significant sustainability and social
impact. High Social Impact Investments include (i) debt obligations that offer a below-market interest rate and (ii) equity investments
that may not generate a market rate of return.

High Social Impact Investment debt obligations are unrated and of below-investment
grade quality, and involve a greater risk of default and price decline than investment grade investments. High Social Impact Investments
are illiquid, and the Fund may be unable to dispose of them at current carrying values.

Any Fund investment in High Social Impact Investments is fair valued
pursuant to valuation procedures adopted by the Fund’s Board and implemented by the Adviser. See “Valuing Shares” in
this Prospectus. High Social Impact Investments by the Fund may be direct investments in an issuer or investments in an intermediate entity
that then makes High Social Impact Investments, such as Calvert Impact Capital, Inc. (“CIC”) (as discussed below).

Pursuant to an exemptive order issued by the SEC, the Fund may invest
in Community Investment Notes (“Notes”) issued by CIC as part of the Fund’s High Social Impact Investments. CIC is a
nonstock corporation organized under the laws of the State of Maryland and designed to operate as a non-profit organization within the
meaning of the Internal Revenue Code of 1986, as amended. CIC focuses its work on offering investors the ability to support organizations
that strengthen communities and sustain our planet. CIC issues Notes with fixed-rates of interest to domestic individuals and institutional
investors and the proceeds from the Notes primarily are used to provide financing to community development organizations, projects, funds
and other social enterprises across a variety of impact sectors, including community development, microfinance, affordable housing, small
business, renewable energy, environmental sustainability, education, health, and sustainable agriculture (collectively, the “Participating
Borrowers”) with missions that may include addressing climate change, supporting quality education, promoting financial inclusion,
strengthening women’s empowerment, and increasing access to quality affordable housing. CIC issues Notes with interest rates that
currently range from 0%–4% and terms currently ranging from six months to 20 years, and in turn makes loans to Participating Borrowers
at rates determined through consideration of the general current market, the Participating Borrower’s positive social and/or environmental
impact and the Participating Borrower’s risk level.

The Adviser has licensed use of the Calvert name to CIC and provides
other types of support. The Adviser’s President and Chief Executive Officer (and the only director/trustee on the Fund Board that
is an “interested person” of the Fund) serves on the CIC Board. In addition, another director/trustee on the Fund Board serves
as a director emeritus on the CIC Board.

Shareholder Advocacy and Corporate Responsibility

CRM uses strategic engagement and shareholder advocacy to encourage
positive change in companies. CRM’s activities may include, but are not limited to:

Direct Dialogue
with Company Management.
CRM, or its agent, may initiate dialogue with management through phone calls, letters and in-person
meetings. Through its interaction, CRM seeks to learn about management’s successes and challenges and to press for improvement on
issues of concern.

Proxy Voting.
As a shareholder of the companies in its portfolio, the Fund typically has an opportunity each year to express its views on issues
of corporate governance and sustainability at annual stockholder meetings. CRM votes proxies consistent with CRM’s Proxy Voting
Policies and Procedures attached to the SAI.

Shareholder
Resolutions.
CRM may propose that companies submit resolutions to their shareholders on a variety of ESG issues. CRM believes
that submitting shareholder resolutions may help establish dialogue with management and encourage companies to take action.

Management and Organization

Management. The Fund’s
investment adviser is Calvert Research and Management (“CRM”). CRM’s address is 1825 Connecticut Avenue NW, Suite 400,
Washington, DC 20009. EV LLC, (“EV”) serves as trustee of CRM, which is a subsidiary of Eaton Vance Management (“Eaton
Vance”). Prior to March 1, 2021, each of CRM, EV and Eaton Vance were direct or indirect subsidiaries of Eaton Vance Corp. (“EVC”),
a Maryland corporation and publicly-held holding company with offices at Two International Place, Boston, Massachusetts 02110. On March
1, 2021, Morgan Stanley acquired EVC, and CRM, Eaton Vance and EV each became an indirect, wholly owned subsidiary of Morgan Stanley.

Morgan Stanley (NYSE: MS), whose principal offices are at 1585 Broadway,
New York, New York 10036, is a preeminent global financial services firm engaged in securities trading and brokerage activities, as well
as providing investment banking, research and analysis, financing and financial advisory services. As of September 30, 2021, Morgan Stanley’s
asset management operations had aggregate assets under management of approximately $1.5 trillion.

Calvert Mortgage Access Fund 25 Prospectus dated [______], 2022

The Fund’s annual shareholder report covering the fiscal year
ended September 30 will provide information regarding the basis for the Trustees’ approval of the Fund’s investment advisory
agreement.

Under its investment advisory agreement, CRM receives a monthly fee
as follows:

Average Daily Net Assets Annual Fee Rate
   
   
   
   

The portfolio managers of the Fund are Andrew Szczurowski and Alexander
Payne (each since inception). Messrs. Szczurowski and Payne are Vice Presidents of CRM and have been employees of the Eaton Vance organization
for more than five years. They each currently manage other funds.

The Statement of Additional Information provides additional information
about each portfolio manager’s compensation, other accounts managed by each portfolio manager, and each portfolio manager’s
ownership of Fund shares.

CRM serves as administrator of the Fund, providing the Fund with administrative
services and related office facilities. In return, each Class of the Fund is authorized to pay CRM a monthly administrative fee equal
to 0.12% annually of average daily net assets.

Eaton Vance provides sub-transfer agency and related services to Calvert
mutual funds pursuant to a Sub-Transfer Agency Support Services Agreement. For its services under the agreement, Eaton Vance receives
an aggregate fee from such funds equal to its actual expenses incurred in performing such services.

Organization. The
Fund is a series of The Calvert Fund, a Massachusetts business trust.  The Fund offers multiple classes of shares. Each Class represents
a pro rata interest in the Fund but is subject to different expenses and rights. The Fund does not hold annual shareholder meetings but
may hold special meetings for matters that require shareholder approval (such as electing or removing Trustees, approving management or
advisory contracts or changing investment policies that may only be changed with shareholder approval).

Valuing Shares

The Fund values its shares once each day only when the New York Stock
Exchange (the “Exchange”) is open for trading (typically Monday through Friday), as of the close of regular trading on the
Exchange (normally 4:00 p.m. Eastern Time). If trading on the Exchange is halted for the day before the scheduled close of regular trading,
the Fund’s net asset value per share generally will still be calculated as of the scheduled close of regular trading on the Exchange.
The purchase price of Fund shares is their net asset value (plus any applicable sales charge), which is derived from the value of Fund
holdings. When purchasing or redeeming Fund shares through a financial intermediary, your financial intermediary must receive your order
by the close of regular trading on the Exchange in order for the purchase price or the redemption price to be based on that day’s
net asset value per share. It is the financial intermediary’s responsibility to transmit orders promptly. The Fund may accept purchase
and redemption orders as of the time of their receipt by certain financial intermediaries (or their designated intermediaries).

The Board has adopted procedures for valuing investments (the “Procedures”) and
has delegated to the investment adviser(s) the daily valuation of such investments. Pursuant to the Procedures, securities and other investments
held by the Fund are generally valued at market value. Exchange-listed investments (including certain derivatives) are normally valued
at last sale or closing prices. Exchange-traded options are valued at the mean of the bid and asked prices at valuation time as reported
by the Options Price Reporting Authority for U.S. listed options, or by the relevant exchange or board of trade for non-U.S. listed options.
Non-exchange traded derivatives are normally valued on the basis of quotes obtained from brokers and dealers or independent pricing services.
Most loans and other debt obligations are valued using prices supplied by one or more pricing services.

An instrument’s “fair value” is the amount that the
owner might reasonably expect to receive for the instrument upon its current sale in the ordinary course of business. Under certain limited
circumstances, the Fund may use fair value pricing if, for example, market prices or a pricing service’s prices (as applicable) are unavailable
or deemed unreliable, or if events occur after the close of a securities market (usually a foreign market) and before portfolio assets
are valued that cause or are likely to cause a market quotation to be unavailable or unreliable, such as corporate actions, regulatory
news, or natural disasters or governmental actions that may affect investments in a particular sector, country or region. In addition,
for foreign equity securities and total return swaps and futures contracts on foreign indices that meet certain criteria, the Board has
approved the use of a fair value service that values such investments to reflect market trading that occurs after the close of the applicable
foreign markets of comparable securities or other investments that have a strong

Calvert Mortgage Access Fund 26 Prospectus dated [______], 2022

correlation to the fair valued investments. An investment that is fair
valued may be valued at a price higher or lower than (i) actual market quotations, (ii) the value determined by other funds using their
own fair valuation procedures, or (iii) the price at which the investment could have been sold during the period in which fair valuation
was used with respect to such investment to calculate the Fund’s NAV. Because foreign investments held by the Fund, if any, may
trade on days when Fund shares are not priced, the value of such investments, and thus the net asset value of the Fund’s shares,
can change on days when Fund shares cannot be redeemed or purchased. CRM has established a Valuation Committee that oversees the valuation
of investments.

Purchasing Shares

Set forth below is information about the manner in which the
Fund offers shares. A financial intermediary may offer Fund shares subject to variations in or elimination of the Fund sales charges (“variations”),
provided such variations are described in this Prospectus. All variations described in Appendix B are applied by, and the responsibility
of, the identified financial intermediary. Sales charge variations may apply to purchases, sales, exchanges and reinvestments of Fund
shares and a shareholder transacting in Fund shares through an intermediary identified on Appendix B should read the terms and conditions
of Appendix B carefully. See also “Shareholder Account Features – ‘Street Name’ Accounts.” For the variations
applicable to shares offered through certain financial intermediaries, please see Appendix B – Financial Intermediary Sales Charge
Variations. A variation that is specific to a particular financial intermediary is not applicable to shares held directly with the Fund
or through another intermediary.

You may purchase shares through your financial intermediary or by mailing
an account application form to the transfer agent (see back cover for address). Purchase orders will be executed at the net asset value
(plus any applicable sales charge) next determined after their receipt in proper form (meaning that the order is complete and contains
all necessary information) by the Fund’s transfer agent. The Fund’s transfer agent or your financial intermediary must receive
your purchase in proper form no later than the close of regular trading on the Exchange (normally 4:00 p.m. Eastern Time) for your purchase
to be effected at that day’s net asset value. If you purchase shares through a financial intermediary, that intermediary may charge
you a fee for executing the purchase for you.

The Fund may suspend the sale of its shares at any time and any purchase
order may be refused for any reason. The U.S. registered Calvert funds generally do not accept investments from residents of the European
Union, the United Kingdom or Switzerland.  The funds also do not accept investments from other non-U.S. residents, provided that
a fund may accept investments from certain non-U.S. investors at the discretion of the principal underwriter. The Fund does not issue
share certificates.

As used throughout this Prospectus, the term “employer sponsored
retirement plan” includes the following: an employer sponsored pension or profit sharing plan that qualifies under section 401(a)
of the Code (such as a 401(k) plan, money purchase pension, profit sharing and defined benefit plan); ERISA covered 403(b) plan; Taft-Hartley
multi-employer plan; and non-qualified deferred compensation arrangements that operate in a similar manner to a qualified retirement plan
(including 457 plans and executive deferred compensation arrangements). Individual Retirement Accounts (“IRAs”) are not employer
sponsored retirement plans for purposes of this definition.

Class A and Class C Shares

Your initial investment must be at least $1,000. After your initial
investment, additional investments may be made in any amount at any time by sending a check payable to the order of the Fund or the transfer
agent directly to the transfer agent (see back cover for address). Please include your name and account number and the name of the Fund
and Class of shares with each investment. The Fund no longer accepts direct purchases of Class C shares by accounts for which no broker-dealer
or other financial intermediary is specified. Any direct purchase received by the Fund’s transfer agent for Class C shares for such accounts
will automatically be invested in Class A shares.

The minimum initial investment amount and Fund policy of redeeming accounts
with low account balances are waived for bank automated investing accounts, certain group purchase plans (including employer sponsored
retirement plans and proprietary fee-based programs sponsored by financial intermediaries) and for persons affiliated with CRM, its affiliates
and certain Fund service providers (as described in the SAI).

Class I Shares

Your initial investment must be at least $250,000, except as noted
below. Class I shares are offered to clients of financial intermediaries who (i) charge such clients an ongoing fee for advisory,
investment, consulting or similar services, or (ii) have entered into an agreement with the principal underwriter to offer Class I
shares through a no-load network or platform. Such clients may include individuals, corporations, endowments, foundations and
employer sponsored retirement plans. Class I shares may also be available through brokerage platforms of broker-dealer firms that
have agreements with the Fund’s principal underwriter to offer Class I shares solely when acting as an agent for the investor.
An investor acquiring Class I shares through such platforms may be required to pay a commission and/or other forms of compensation
to the broker. The Fund offers other share classes that have different fees and expenses.  Class I shares also are offered
to investment and institutional clients of CRM and its affiliates and certain persons affiliated with CRM.

Calvert Mortgage Access Fund 27 Prospectus dated [______], 2022

The Class I minimum initial investment is waived for persons affiliated
with CRM, its affiliates and certain Fund service providers (as described in the SAI). The minimum initial investment also is waived for:
(i) permitted exchanges; (ii) employer sponsored retirement plans; (iii) corporations, endowments and foundations with assets of at least
$100 million; (iv) Class I shares purchased through the brokerage platforms described above; and (v) accounts of clients of financial
intermediaries who (a) charge an ongoing fee for advisory, investment, consulting or similar services, or (b) have entered into an agreement
with the principal underwriter to offer Class I shares through a no-load network or platform (in each case, as described above).

Class I shares may be purchased through a financial intermediary or
by requesting your bank to transmit immediately available funds (Federal Funds) by wire. To make an initial investment by wire, you must
complete an account application and telephone Calvert Shareholder Services at 1-800-368-2745 to be assigned an account number. You may
request an account application by calling 1-800-368-2745 Monday through Thursday, 9:00 a.m. to 5:30 p.m. (Eastern Time) and Friday, 9:00
a.m. to 5:00 p.m. (Eastern Time). Shareholder Services must be advised by telephone of each additional investment by wire.

Class R6 Shares

Class R6 shares are offered to employer sponsored retirement plans held
in plan level or omnibus accounts; endowments; foundations; local, city, and state governmental institutions; corporations; charitable
trusts; trust companies; private banks and their affiliates; and insurance companies; clients of Eaton Vance Investment Counsel; investors
who purchase shares through asset-based fee programs of certain financial intermediaries that have entered into an agreement with the
Fund’s principal underwriter to offer Class R6 shares through such programs; and investment companies. In order to offer Class R6
shares to investors other than employer sponsored retirement plans, a financial intermediary must enter into a written agreement with
the Fund’s principal underwriter to offer such shares.

There is no initial investment minimum for: employer sponsored retirement
plans; private banks and their affiliates; investors who purchase shares through asset-based fee programs as described above, provided
the aggregate value of such program’s assets under management invested in Calvert funds is at least $1,000,000; and investment companies
sponsored by the Calvert organization. For all other eligible investors, the initial investment must be at least $1,000,000. Subsequent
investments of any amount may be made at any time. Please call 1-800-368-2745 Monday through Thursday, 9:00 a.m. to 5:30 p.m. (Eastern
Time) and Friday, 9:00 a.m. to 5:00 p.m. (Eastern Time) for further information.

Class R6 shares may be purchased through a financial intermediary or
by requesting your bank to transmit immediately available funds (Federal Funds) by wire. To make an initial investment by wire, you must
complete an account application and telephone Calvert Shareholder Services at 1-800-368-2745 to be assigned an account number. You may
request an account application by calling 1-800-368-2745 Monday through Thursday, 9:00 a.m. to 5:30 p.m. (Eastern Time) and Friday, 9:00
a.m. to 5:00 p.m. (Eastern Time). Shareholder Services must be advised by telephone of each additional investment by wire.

Subsequent
Investments.
Subsequent investments of any amount may be made at any time, including through automatic investment each month
or quarter from your bank account. You may make automatic investments of $50 or more each month or each quarter from your bank account
provided such investments equal a minimum of $200 per year. You can establish bank automated investing on the account application or by
providing written instructions to the Fund’s transfer agent. Please call 1-800-368-2745 Monday through Thursday, 9:00 a.m. to 5:30
p.m. (Eastern Time) and Friday, 9:00 a.m. to 5:00 p.m. (Eastern Time) for further information.

You also may make additional investments by accessing your account via
the Calvert website at www.calvert.com. The trade date of purchases made through the Internet from a pre-designated bank account will
be the day the purchase is requested through the Calvert website (provided the request is on a business day and submitted no later than
the close of regular trading on the Exchange). For more information about purchasing shares through the Internet, please call 1-800-368-2745
Monday through Thursday, 9:00 a.m. to 5:30 p.m. (Eastern Time) and Friday, 9:00 a.m. to 5:00 p.m. (Eastern Time).

Inactive
Accounts.
In accordance with state “unclaimed property” (also known as “escheatment”) laws, your Fund
shares may legally be considered abandoned and required to be transferred to the relevant state if no account activity or contact with
the Fund or your financial intermediary occurs within a specified period of time. Please initiate contact a least once per calendar year
and maintain a current and valid mailing address on record for your account. For more information, please see https://www.calvert.com/mutual-funds-and-abandoned-property.php
or please contact us at 1-800-368-2745.

Calvert Mortgage Access Fund 28 Prospectus dated [______], 2022

 

Restrictions
on Excessive Trading and Market Timing.
The Fund is not intended for excessive trading or market timing. Market timers
seek to profit by rapidly switching money into a fund when they expect the share price of the fund to rise and taking money out of the
fund when they expect those prices to fall. By realizing profits through short-term trading, shareholders that engage in rapid purchases
and sales (including exchanges, if permitted) of a fund’s shares may dilute the value of shares held by long-term shareholders.
Volatility resulting from excessive purchases and sales of fund shares, especially involving large dollar amounts, may disrupt efficient
portfolio management. In particular, excessive purchases and sales of a fund’s shares may cause a fund to have difficulty implementing
its investment strategies, may force the fund to sell portfolio securities at inopportune times to raise cash or may cause increased expenses
(such as increased brokerage costs, realization of taxable capital gains without attaining any investment advantage or increased administrative
costs).

A fund that invests all or a portion of its assets in foreign securities
may be susceptible to a time zone arbitrage strategy in which shareholders attempt to take advantage of fund share prices that may not
reflect developments in a foreign securities market that occur after the close of such market but prior to the pricing of fund shares.
In addition, a fund that invests in securities that are, among other things, thinly traded, traded infrequently or illiquid, is susceptible
to the risk that the current market price for such securities may not accurately reflect current market values. A shareholder may seek
to engage in short-term trading to take advantage of these pricing differences (commonly referred to as “price arbitrage”).
The investment adviser is authorized to use the fair value of a security if prices are unavailable or are deemed unreliable (see “Valuing
Shares”). The use of fair value pricing and the restrictions on excessive trading and market timing described below are intended
to reduce a shareholder’s ability to engage in price or time zone arbitrage to the detriment of the Fund.

The Boards of the Calvert funds have adopted policies to discourage
short-term trading and market timing and to seek to minimize their potentially detrimental effects (the “Policy”). Under the
Policy, the Board has delegated to Eaton Vance Management, acting in its capacity as the Fund’s sub-transfer agent (“Eaton
Vance”) the responsibility to reject or cancel a purchase order, suspend or terminate an exchange privilege or terminate the ability
of a shareholder to invest in the Calvert funds if Eaton Vance determines that a proposed transaction involves market timing or excessive
trading that it believes is likely to be detrimental to the Fund.

Pursuant to the Policy, “two round-trips” completed by a
Fund shareholder within 90 days through one or more accounts (the “Limitation”) generally will be deemed to be indicative
of market timing or trading excessively in fund shares.  A “round trip” is defined as a purchase or exchange into a Fund
followed or preceded by a redemption or exchange out of the Fund.  Purchases and redemptions subject to the Limitation include those
made by exchanging to or from another fund. Eaton Vance will evaluate transactions in Fund shares that violate the Limitation to determine
whether they are likely to be detrimental to the Fund. In making such a determination, Eaton Vance may consider various factors, such
as the amount, frequency and nature of trading activity. If such a determination is made, the Fund shareholder may be subject to restrictions
on trading Fund shares, as described above. Eaton Vance uses reasonable efforts to detect market timing and excessive trading activity
that is likely to be detrimental to the Fund, but it cannot ensure that it will be able to identify all such cases. Eaton Vance may also
reject or cancel any purchase order (including an exchange) from a shareholder or group of shareholders for any other reason. In applying
the Policy, and in particular when determining whether a transaction is likely to be detrimental to a Fund, Eaton Vance will be required
to make judgments that are inherently subjective and will depend on the specific facts and circumstances. Such determinations will be
made in a manner believed to be in the best interest of the Fund’s shareholders. No Calvert fund has any arrangement to permit market
timing.

The following Fund share transactions generally are exempt from the
Policy because they generally do not raise market timing or excessive trading concerns:

· transactions (i) made pursuant to the Fund’s systematic purchase, exchange or redemption plan, (ii) made as the result of automatic
reinvestment of dividends or distributions, or (iii) initiated by the Fund (e.g., for transactions due to a failure to meet applicable
account minimums);
· transactions made by participants in employer sponsored retirement plans involving (i) participant payroll or employer contributions
or loan repayments, (ii) redemptions as part of plan terminations or at the direction of the plan, mandatory retirement distributions,
or (iii) rollovers;
· transactions in shares of Calvert Ultra-Short Duration Income Fund; or
· investments in a fund by ReFlow in connection with the ReFlow liquidity program (if applicable to the Fund, the ReFlow liquidity program
is described under “Investment Objectives & Principal Policies and Risks” above).

The following Fund share transactions generally are exempt from the
Limitation; however, these transactions are subject to monitoring by Eaton Vance and may be subject to restrictions if deemed likely to
be detrimental to the Fund:

· transactions made by model-based discretionary advisory accounts; or
· transactions made by funds that invest in the Fund as part of an asset reallocation in accordance with their investment policies or
in response to Fund inflows and outflows.

Calvert Mortgage Access Fund 29 Prospectus dated [______], 2022

It may be difficult for Eaton Vance to identify market timing or excessive
trading in omnibus accounts traded through financial intermediaries. Eaton Vance has provided guidance to financial intermediaries (such
as banks, broker-dealers, insurance companies and retirement administrators) concerning the application of the Policy to Fund shares held
in omnibus accounts maintained and administered by such intermediaries, including guidance concerning situations where market timing or
excessive trading is considered to be detrimental to the Fund. Eaton Vance may rely on a financial intermediary’s policy to restrict
market timing and excessive trading if it believes that policy is likely to prevent market timing that is likely to be detrimental to
the Fund. Such policy may be more or less restrictive than the Policy. Although Eaton Vance reviews trading activity at the omnibus account
level for activity that indicates potential market timing or excessive trading activity, Eaton Vance typically will not request or receive
individual account data unless suspicious trading activity is identified. Eaton Vance generally relies on financial intermediaries to
monitor trading activity in omnibus accounts in good faith in accordance with their own policies or the Policy. Eaton Vance cannot ensure
that these financial intermediaries will in all cases apply the Policy or their own policies, as the case may be, to accounts under their
control.

Choosing
a Share Class.
 The Fund offers different classes of shares. The different classes of shares represent investments in
the same portfolio of securities, but the classes are subject to different expenses and privileges, and will likely have different share
prices due to differences in class expenses. A share class also may be subject to a sales charge. In choosing the class of shares that
suits your investment needs, you should consider:

· how long you expect to own your shares;
· how much you intend to invest; and
· the total operating expenses associated with owning each class.

Each investor’s considerations are different. You should speak
with your financial intermediary to help you decide which class of shares to purchase. Set forth below is a brief description of each
class of shares offered by the Fund.

Class
A shares
are offered at net asset value plus a front-end sales charge of up to 4.75%. This charge is deducted from the amount
you invest. The Class A sales charge is reduced for purchases of $50,000 or more. The sales charge applicable to your purchase may be
reduced under the right of accumulation or a statement of intention, which are described in “Reducing or Eliminating Class A Sales
Charges” under “Sales Charges” below. Some investors may be eligible to purchase Class A shares at net asset value under
certain circumstances, which are also described below. Class A shares pay distribution and service fees equal to 0.25% annually of average
daily net assets.

Class
C shares
are offered through financial intermediaries at net asset value with no front-end sales charge. If you sell your Class
C shares within 12 months of purchase, you generally will be subject to a contingent deferred sales charge or “CDSC.” The
CDSC is deducted from your redemption proceeds. Under certain circumstances, the CDSC for Class C may be waived (such as certain redemptions
from employer sponsored retirement plans). See “CDSC Waivers” under “Sales Charges” below. Class C shares pay
distribution and service fees equal to 1.00% annually of average daily net assets. Orders for Class C shares of one or more Calvert funds
will be refused when the total value of the purchase (including the aggregate market value of all Calvert fund shares held within the
purchasing shareholder’s account(s)) is $1 million or more. Investors considering cumulative purchases of $1 million or more should
consider whether another Class of shares would be more appropriate and consult their financial intermediary. The Fund no longer accepts
direct purchases of Class C shares by accounts for which no broker-dealer or other financial intermediary is specified. Any direct purchase
received by a Fund’s transfer agent for Class C shares for such accounts will automatically be invested in Class A shares. In addition,
Class C shares held in an account for which no financial intermediary is specified and which are not subject to a CDSC will periodically
be converted to Class A shares.

Class
I shares
are offered to clients of financial intermediaries who (i) charge such clients an ongoing fee for advisory, investment,
consulting or similar services, or (ii) have entered into an agreement with the principal underwriter to offer Class I shares through
a no-load network or platform. Such clients may include individuals, corporations, endowments, foundations and employer sponsored retirement
plans. Class I shares may also be available through brokerage platforms of broker-dealer firms that have agreements with the Fund’s
principal underwriter to offer Class I shares solely when acting as an agent for the investor. An investor acquiring Class I shares through
such platforms may be required to pay a commission and/or other forms of compensation to the broker. Class I shares are also offered to
investment and institutional clients of CRM and its affiliates, and certain persons affiliated with CRM (including employees, officers
and directors of CRM’s affiliates). Class I shares do not pay distribution or service fees.

Class
R6 shares
are offered at net asset value to employer sponsored retirement plans and certain other investors as described under
“Class R6 Shares” above. Class R6 shares are not subject to distribution fees, service fees or sub-accounting/recordkeeping
or similar fees paid to financial intermediaries.

Calvert Mortgage Access Fund 30 Prospectus dated [______], 2022

Payments
to Financial Intermediaries.
 In addition to payments disclosed under “Sales Charges” below, the principal
underwriter, out of its own resources, may make cash payments to certain financial intermediaries (which may include affiliates of the
principal underwriter and investment adviser) who provide marketing support, transaction processing and/or administrative services and,
in some cases, include some or all Calvert funds in preferred or specialized selling programs. Payments made by the principal underwriter
to a financial intermediary may be significant and are typically in the form of fees based on Fund sales, assets, transactions processed
and/or accounts attributable to that financial intermediary. Financial intermediaries also may receive amounts from the principal underwriter
in connection with educational or due diligence meetings that include information concerning Calvert funds. The principal underwriter
may pay or allow other promotional incentives or payments to financial intermediaries to the extent permitted by applicable laws and regulations.

Certain financial intermediaries that maintain fund accounts for the
benefit of their customers provide sub-accounting, recordkeeping and/or administrative services to the Calvert funds and are compensated
for such services by the funds, provided that no such compensation is paid with respect to Class R6 shares. As used in this Prospectus,
the term “financial intermediary” includes any broker, dealer, bank (including bank trust departments), registered investment
adviser, financial planner, a retirement plan and/or its administrator, their designated intermediaries and any other firm having a selling,
administration or similar agreement with the principal underwriter or its affiliates.

Sales Charges

Class A Front-End
Sales Charge.
Class A shares are offered at net asset value per share plus a sales charge that is determined by the amount
of your investment. The current sales charge schedule is:

Amount of Purchase Sales Charge*
as Percentage of
Offering Price
Sales Charge*
as Percentage of Net
Amount Invested
Dealer Commission
as a Percentage of
Offering Price
Less than $100,000 2.25% 2.30% 2.00%
$100,000 but less than $250,000 1.75% 1.78% 1.50%
$250,000 but less than $500,000 0.00%** 0.00%** 1.25%**
$500,000 but less than $1,000,000 0.00%** 0.00%** 0.85%**
$1,000,000 but less than $3,000,000 0.00%** 0.00%** 0.75%**
$3,000,000 but less than $5,000,000 0.00%** 0.00%** 0.75%**
$5,000,000 or more 0.00%** 0.00%** 0.50%**
* Because the offering price per share is rounded to two decimal places, the actual sales charge you pay on a purchase of Class A shares
may be more or less than your total purchase amount multiplied by the applicable sales charge percentage.
** No sales charge is payable at the time of purchase on investments of $250,000 or more. The principal underwriter will pay a commission
to financial intermediaries on sales of $250,000 or more as follows: 1.25% on amounts of $250,000 or more but less than $500,000, 0.85%
on amounts of $500,000 or more but less than $1 million, 0.75% on amounts of $1 million or more but less than $5 million and 0.50% on
amounts of $5 million or more. A CDSC of 1.00% will be imposed on such investments (as described below) in the event of redemptions within
18 months of purchase.

Reducing
or Eliminating Class A Sales Charges.
Front-end sales charges on purchases of Class A shares may be reduced under the right
of accumulation or under a statement of intention. To receive a reduced sales charge, you must inform your financial intermediary or the
Fund at the time you purchase shares that you qualify for such a reduction. If you do not let your financial intermediary or the Fund
know you are eligible for a reduced sales charge at the time of purchase, you will not receive the discount to which you may otherwise
be entitled.

Right
of Accumulation.
Under the right of accumulation, the sales charge you pay is reduced if the current market value of your holdings
in the Fund or any other Calvert fund (based on the current maximum public offering price) plus your new purchase total $50,000 or more.
Shares owned by you, your spouse and children under age twenty-one may be combined for purposes of the right of accumulation, including
shares held for the benefit of any of you in omnibus or “street name” accounts. In addition, shares held in a trust or fiduciary
account of which any of the foregoing persons is the sole beneficiary (including employer sponsored retirement plans and IRAs) may be
combined for purposes of the right of accumulation. Shares purchased and/or owned in a SEP, SARSEP and SIMPLE IRA plan may be combined
for purposes of the right of accumulation for the plan and its participants. You may be required to provide documentation to establish
your ownership of shares included under the right of accumulation (such as account statements for you, your spouse and children or marriage
certificates, birth certificates and/or trust or other fiduciary-related documents).

Calvert Mortgage Access Fund 31 Prospectus dated [______], 2022

 

Statement
of Intention.
Under a statement of intention, purchases of $50,000 or more made over a 13-month period are eligible for reduced
sales charges. Shares eligible under the right of accumulation (other than those included in employer sponsored retirement plans) may
be included to satisfy the amount to be purchased under a statement of intention. Under a statement of intention, the principal underwriter
may hold 5% of the dollar amount to be purchased in escrow in the form of shares registered in your name until you satisfy the statement
or the 13-month period expires. A statement of intention does not obligate you to purchase (or the Fund to sell) the full amount indicated
in the statement. If during the 13-month period you redeem any of the shares that you purchased pursuant to the statement of intention,
the value of the redeemed shares will not be included for purposes of satisfying your statement of intention. For additional information
about statements of intention, see “Sales Charges” in the SAI.

Class A shares are offered at net asset value (without a sales charge)
to accounts of clients of financial intermediaries who (i) charge an ongoing fee for advisory, investment, consulting or similar services,
or (ii) have entered into an agreement with the principal underwriter to offer Class A shares through a no-load network or platform, or
self-directed brokerage accounts that may or may not charge transaction fees to customers; or (iii) employer sponsored retirement plans.
Class A shares also are offered at net asset value to investment and institutional clients of CRM and its affiliates; certain persons
affiliated with CRM; direct purchases of shares by accounts where no financial intermediary is specified; and to certain fund service
providers as described in the SAI. Class A shares are also offered at net asset value to shareholders who make a permitted direct transfer
or roll-over to a Calvert prototype IRA from an employer-sponsored retirement plan previously invested in Calvert funds (applicable only
to the portion previously invested in Calvert funds), provided that sufficient documentation is provided to the transfer agent of such
transfer or roll-over at the time of the account opening. Class A shares may also be purchased at net asset value pursuant to the exchange
privilege and when distributions are reinvested. A financial intermediary may not, in accordance with its policies and procedures, offer
one or more of the waiver categories described above and shareholders should consult their financial intermediary for more information.
The Fund may eliminate, modify or add to the terms of these sales charge waivers at any time without providing notice to shareholders.

Contingent
Deferred Sales Charge. 
Class A and Class C shares are subject to a CDSC on certain redemptions. The CDSC generally is
paid to the principal underwriter. Class A shares purchased at net asset value in amounts of $1 million or more are subject to a 0.80%
CDSC if redeemed within 12 months of purchase. Class C shares are subject to a 1.00% CDSC if redeemed within 12 months of purchase. CDSCs
are based on the lower of the net asset value at the time of purchase or at the time of redemption. Shares acquired through the reinvestment
of distributions are exempt from the CDSC. Redemptions are made first from shares that are not subject to a CDSC.

The sales commission payable to financial intermediaries in connection
with sales of Class C shares is described under “Distribution and Service Fees” below.

CDSC Waivers.
CDSCs are waived for certain redemptions pursuant to a Withdrawal Plan (see “Shareholder Account Features”) and in connection
with certain redemptions from employer sponsored retirement plans or IRAs to satisfy required minimum distributions or to return excess
contributions made to IRAs, if applicable. The CDSC is also waived following the death of a beneficial owner of shares (a death certificate
and other applicable documents may be required). In addition, redemptions of Class C shares by certain employer sponsored retirement plans
are not subject to a CDSC if the principal underwriter did not compensate such plans’ financial intermediary at the time of sale as described
under “Distribution and Service Fees.”

Conversion
Feature.  
Effective November 5, 2020 (the “Effective Date”), Class C shares of the Fund will convert
automatically to Class A shares of the Fund during the month following the eight year anniversary of the purchase of such Class C shares.
If a financial intermediary that maintains a Class C shareholder’s account has not tracked the holding period for Class C shares,
Class C shares held as of the Effective Date will automatically convert to Class A shares eight years after the Effective Date. In addition,
Class C shares held in an account with the Fund’s transfer agent for which no financial intermediary is specified and that are not
subject to a CDSC will be converted to Class A shares of the Fund periodically.

In some circumstances, the Board may determine to cease to offer and
subsequently close an existing class of Fund shares. In such circumstances, the Fund may automatically convert the shares for such class
into another share class, subject to prior notice to shareholders of the impacted class. Any such conversion will occur at the respective
net asset value of each class as of the conversion date without the imposition of any fee or other charges by the Fund.

Distribution
and Service Fees.
 Class A and Class C shares have in effect plans under Rule 12b-1 that allow the Fund to pay distribution
fees for the sale and distribution of shares and service fees for personal and/or shareholder account services (so-called “12b-1
fees”). Class C shares pay distribution fees to the principal underwriter of 0.75% of average daily net assets annually. Because
these fees are paid from Fund assets on an ongoing basis, they will increase your cost over time and may cost you more than paying other
types of sales charges. The principal underwriter generally compensates financial intermediaries on sales of Class C shares (except exchange
transactions and reinvestments) in an

Calvert Mortgage Access Fund 32 Prospectus dated [______], 2022

amount equal to 1% of the purchase price of the shares. After the first
year, such financial intermediaries also receive 0.75% of the value of outstanding Class C shares sold by such financial intermediaries
in annual distribution fees. With respect to purchases of Class C shares by certain employer sponsored retirement plans, the principal
underwriter does not compensate the financial intermediary at the time of sale. In such cases, the financial intermediary receives 0.75%
of the value of outstanding Class C shares sold by such financial intermediary in annual distribution fees immediately after the sale.
Class C shares also pay service fees to the principal underwriter equal to 0.25% of average daily net assets annually. Class A shares
pay distribution and service fees equal to 0.25% of average daily net assets annually. After the sale of Class A shares, the principal
underwriter receives the Class A distribution and service fees and generally the financial intermediary receives such fees immediately
after the sale. After the sale of Class C shares, the principal underwriter generally receives the Class C service fees for one year,
thereafter financial intermediaries generally receive such fees. With respect to purchases of Class C shares by certain employer sponsored
retirement plans, the financial intermediary also receives the service fees from the principal underwriter immediately after the sale.
Such amounts are generally paid to financial intermediaries by the principal underwriter based on the value of shares sold by such financial
intermediaries for shareholder servicing performed by such intermediaries. Distribution and service fees are subject to the limitations
contained in the sales charge rule of the Financial Industry Regulatory Authority, Inc.

More information about Fund sales charges is available free of
charge on the Calvert website at www.calvert.com and in the SAI. Please consult the Calvert website for any updates to Fund sales charge
information before making a purchase of Fund shares. Please consult your financial intermediary with respect to any sales charge variations
listed on Appendix B.

Redeeming Shares

You can redeem shares in any of the following ways:

By Mail Send your request to the transfer agent (see back cover for address). The request must be signed exactly as your account is registered (for instance, a joint account must be signed by all registered owners to be accepted) and a Medallion signature guarantee may be required.  Circumstances that may require a Medallion signature guarantee include, but are not limited to, requests to distribute redemption proceeds to a party other than the registered account owner(s); requests to mail redemption proceeds to an address other than the address of record; requests to distribute proceeds to a bank account not on file; requests to re-issue uncashed checks representing redemption proceeds; or transaction requests from an account beneficiary when an account owner is deceased.  You can obtain a Medallion signature guarantee at banks, savings and loan institutions, credit unions, securities dealers, securities exchanges, clearing agencies and registered securities associations that participate in The Securities Transfer Agents Medallion Program, Inc. (STAMP, Inc.).  Only Medallion signature guarantees issued in accordance with STAMP, Inc. will be accepted.  You may be asked to provide additional documents if your shares are registered in the name of a corporation, partnership or fiduciary.
By Telephone Certain shareholders can redeem by calling 1-800-368-2745 Monday through Thursday, 9:00 a.m. to 5:30 p.m. (Eastern Time) and Friday, 9:00 a.m. to 5:00 p.m. (Eastern Time). Proceeds of a telephone redemption are generally limited to $100,000 per account (which may include shares of one or more Calvert funds) and can be sent only to the account address or to a bank pursuant to prior instructions.
By Internet Certain shareholders can redeem by logging on to the Calvert website at www.calvert.com. Proceeds of internet redemptions are generally limited to $100,000 per account (which may include shares of one or more Calvert funds) and can be sent only to the account address or to a bank pursuant to prior instructions.  
For Additional Information Please call 1-800-368-2745 Monday through Thursday, 9:00 a.m. to 5:30 p.m. (Eastern Time) and Friday, 9:00 a.m. to 5:00 p.m. (Eastern Time).
Through a Financial Intermediary Your financial intermediary is responsible for transmitting the order promptly.  A financial intermediary may charge a fee for this service.

Calvert Mortgage Access Fund 33 Prospectus dated [______], 2022

A redemption may be requested by sending a Medallion signature guaranteed
letter of instruction to the transfer agent (see back cover for address) or, for telephone redemptions as described above, by calling
1-800-368-2745. Certain redemption requests, including those involving shares held by certain corporations, trusts or certain other entities
and shares that are subject to certain fiduciary arrangements, may require additional documentation and may be redeemed only by mail.
The Fund’s transfer agent or your financial intermediary must receive your redemption in proper form (meaning that it is complete and
contains all necessary information) no later than the close of regular trading on the Exchange (normally 4:00 p.m. Eastern Time) for your
redemption to be effected at that day’s net asset value. Redemption proceeds are reduced by the amount of any applicable CDSC and
any federal income and state tax required to be withheld.

Redemption proceeds typically are paid to the redeeming shareholder
in cash up to two business days after the redemption, but payment could take up to seven days, as permitted by the 1940 Act for the reasons
discussed below. The actual number of days following receipt of a redemption request in which the Fund typically expects to pay redemption
proceeds generally will depend on how you hold your shares with the Fund.

If your shares are held in a “street name” account with
a financial intermediary (see “Shareholder Account Features – ‘Street Name’ Accounts”), your intermediary
will elect through National Securities Clearing Corporation (“NSCC”) to settle redemptions either one business day or two
business days after the redemption date and redemption proceeds normally will be wired to your financial intermediary on the settlement
date pursuant to that election.

If your shares are held directly with the Fund’s transfer agent, redemptions
normally will be settled in one business day after the redemption date and redemption proceeds will be sent by regular mail on such date.
However, if you have given proper written authorization in advance, you may request that redemption proceeds be wired on the settlement
date directly to your bank account in any bank in the United States. While not currently charged by the Fund, you may be required to pay
a wire transfer fee by your bank. If you request expedited mail delivery of your redemption proceeds and the Fund is able to accommodate
your request, charges may apply. You may redeem all or a portion of the shares from your account on any day the Fund is open for business,
provided the amount requested is not on hold or held in escrow pursuant to a statement of intention. When you purchase by check or with
ACH funds transfer, the purchase will be on hold for up to 10 days from the date of receipt. During the hold period, redemption proceeds
will not be sent until the transfer agent is reasonably satisfied that the purchase payment has been collected.

The Fund typically expects to meet redemption requests by (i) distributing
any cash holdings, (ii) selling portfolio investments and/or (iii) borrowing from a bank under a line of credit. In addition to the foregoing,
the Fund also may distribute securities as payment (a so-called “redemption in-kind”), in which case the redeeming shareholder
may pay fees and commissions to convert the securities to cash. Unless requested by a shareholder, the Fund generally expects to limit
use of redemption in-kind to stressed market conditions, but is permitted to do so in other circumstances. A shareholder who wishes to
receive redemption proceeds in-kind must notify the Fund on or before submitting the redemption request by calling 1-800-368-2745. Securities
distributed in a redemption in-kind would be valued pursuant to the Fund’s valuation procedures and selected by the investment adviser.
If a shareholder receives securities in a redemption in-kind, the shareholder could incur brokerage or other charges in converting the
securities to cash and the value of such securities would be subject to price fluctuations until sold. There can be no assurance that
the Fund will manage liquidity successfully in all market environments. As a result, the Fund may not be able to pay redemption proceeds
in a timely fashion because of unusual market conditions, an unusually high volume of redemption requests or other factors. Additional
information about redemptions in-kind, including the procedures for submitting such redemption requests, is contained in the Fund’s
SAI.

If your account value falls below $750, you may be asked either to add
to your account or redeem it within 60 days. If you take no action, your account will be redeemed at net asset value and the proceeds
sent to you.

Calvert Mortgage Access Fund 34 Prospectus dated [______], 2022

 

Shareholder Account Features

Distributions.
You may have your Fund distributions paid in one of the following ways:

• Full Reinvest Option Distributions are reinvested in additional shares.  This option will be assigned if you do not specify an option.
• Partial Reinvest Option Dividends and short-term capital gains are paid in cash* and long-term capital gains are reinvested in additional shares.
• Cash Option Distributions are paid in cash.*
• Exchange Option Distributions are reinvested in additional shares of any class of another Calvert fund chosen by you, subject to the terms of that fund’s prospectus.  Before selecting this option, you must obtain a prospectus of the other fund and consider its objectives, risks, and charges and expenses carefully.
* If any distribution check remains uncashed for six months, CRM reserves the right to invest the amount represented by the check in
Fund shares at the then-current net asset value of the Fund and all future distributions will be reinvested.

Information
about the Fund.
From time to time, you may receive the following:

· Semiannual and annual reports containing a list of portfolio holdings as of the end of the second and fourth fiscal quarters, respectively,
performance information and financial statements.
· Periodic account statements, showing recent activity and total share balance.
· Tax information needed to prepare your income tax returns.
· Proxy materials, in the event a shareholder vote is required.
· Special notices about significant events affecting your Fund.

Most fund information (including semiannual and annual reports, prospectuses
and proxy statements) as well as your periodic account statements can be delivered electronically. For more information please go to www.calvert.com.

You may be contacted via mail, telephone or by electronic means by officers
of the Fund, by personnel of the investment adviser or administrator, by the Fund’s transfer agent, by broker-dealer firms, or by
a professional solicitation organization in connection with a solicitation of proxies for a meeting of Fund shareholders.

The Calvert funds have established policies and procedures with respect
to the disclosure of portfolio holdings and other information concerning Fund characteristics. A description of these policies and procedures
is provided below and additionally in the SAI. Such policies and procedures regarding disclosure of portfolio holdings are designed to
prevent the misuse of material, non-public information about the funds.

The Fund will file information regarding its portfolio holdings with
the SEC on its Form N-PORT. The Fund’s annual and semiannual reports (as filed on Form N-CSR) and certain information filed on Form
N-PORT may be viewed on the SEC’s website (www.sec.gov). The most recent fiscal quarter-end holdings may also be viewed on the Calvert
website (www.calvert.com). Portfolio holdings information that is filed with the SEC is posted on the Calvert website approximately 60
days after the end of the quarter to which it relates. Portfolio holdings information as of each month end is posted to the website approximately
one month after such month end. The Fund also posts information about certain portfolio characteristics (such as top ten holdings and
asset allocation) at least quarterly on the Calvert website approximately ten business days after the period and the Fund may also post
performance attribution as of a month end or more frequently if deemed appropriate.

Withdrawal
Plan.
You may redeem shares on a regular periodic basis by establishing a systematic withdrawal plan. Withdrawals will not
be subject to any applicable CDSC if they are, in the aggregate, less than or equal to 12% annually of the greater of either the initial
account balance or the current account balance. Because purchases of Class A shares are generally subject to an initial sales charge,
Class A shareholders should not make withdrawals from their accounts while also making purchases.

Exchange
Privilege.
Each class of Fund shares may be exchanged for shares of the same Class of another Calvert
fund. Exchanges are made at net asset value. If your shares are subject to a CDSC, the CDSC will continue to apply to your new
shares at the same CDSC rate. For purposes of the CDSC, your shares will continue to age from the date of your original purchase of
Fund shares. Except as described below, any class of shares of a fund may be exchanged for any other class of shares of that fund,
provided that the shares being exchanged are no longer subject to a CDSC and the conditions for investing in the other class of
shares described in the applicable prospectus are satisfied. Class C shares are not permitted to be exchanged to Class A shares
unless the CDSC has expired and the exchange is made to facilitate the shareholder’s participation in a fee-based advisory program.
See also Appendix B to this prospectus.

Calvert Mortgage Access Fund 35 Prospectus dated [______], 2022

Before exchanging, you should read the prospectus of the new fund carefully.
Exchanges are subject to the terms applicable to purchases of the new fund’s shares as set forth in its prospectus. If you wish
to exchange shares, write to the transfer agent (see back cover for address), log on to your account at www.calvert.com or call 1-800-368-2745.
Periodic automatic exchanges are also available. The exchange privilege may be changed or discontinued at any time. You will receive at
least 60 days’ notice of any material change to the privilege. This privilege may not be used for “market timing” and
may be terminated for market timing accounts or for any other reason. For additional information, see “Restrictions on Excessive
Trading and Market Timing” under “Purchasing Shares.” Ordinarily exchanges between different funds are taxable transactions
for federal tax purposes, while permitted exchanges of one class for shares of another class of the same fund are not. Shareholders should
consult their tax advisors regarding the applicability of federal, state, local and other taxes to transactions in Fund shares.

Reinvestment
Privilege.
If you redeem shares, you may reinvest at net asset value all or any portion of the redemption proceeds in the same
account and in the same class of shares of the Fund you redeemed from or another Fund, provided that the reinvestment occurs within 90
days of the redemption, the privilege has not been used more than once in the prior 12 months, the redeemed shares were subject to a front-end
sales charge or CDSC and that you are otherwise eligible to invest in that class. Under these circumstances your account will be credited
with any CDSC paid in connection with the redemption. Any CDSC period applicable to the shares you acquire upon reinvestment will run
from the date of your original share purchase. For requests for reinvestment sent to the Fund’s transfer agent, the request must be in
writing. At the time of a reinvestment, you or your financial intermediary must notify the Fund or the transfer agent that you are reinvesting
redemption proceeds in accordance with this privilege. If you reinvest, your purchase will be at the next determined net asset value following
receipt of your request.

Telephone
and Electronic Transactions.
You can redeem or exchange shares by telephone as described in this Prospectus. In addition, certain
transactions may be conducted through the Calvert website. The transfer agent and the principal underwriter have procedures in place to
authenticate telephone and electronic instructions (such as using security codes or verifying personal account information). As long as
the transfer agent and principal underwriter follow reasonable procedures, they will not be responsible for unauthorized telephone or
electronic transactions and you bear the risk of possible loss resulting from these transactions. You may decline the telephone redemption
option on the account application. Telephone instructions are recorded. You should verify the accuracy of your confirmation statements
immediately upon receipt and notify Calvert Shareholder Services of any inaccuracies.

“Street
Name” Accounts.
If your shares are held in a “street name” account at a financial intermediary, that intermediary
(and not the Fund or its transfer agent) will perform all recordkeeping, transaction processing and distribution payments. Because the
Fund does not maintain an account for you, you should contact your financial intermediary to make transactions in shares, make changes
in your account, or obtain account information. You will not be able to utilize a number of shareholder features, such as telephone or
internet transactions, directly with the Fund and certain features may be subject to different requirements. If you transfer shares in
a “street name” account to an account with another financial intermediary or to an account directly with the Fund, you should
obtain historical information about your shares prior to the transfer. If you fail to provide your full account history to your new financial
intermediary following a transfer, you may be ineligible for certain features of the Fund.

Procedures
for Opening New Accounts.
To help the government fight the funding of terrorism and money laundering activities, federal law
requires financial institutions to obtain, verify and record information that identifies each new customer who opens an account with the
Fund and to determine whether such person’s name appears on government lists of known or suspected terrorists or terrorist organizations.
When you open an account, the transfer agent or your financial intermediary will ask you for your name, address, date of birth (for individuals),
residential or business street address (although post office boxes are still permitted for mailing) and social security number, taxpayer
identification number, or other government-issued identifying number. You also may be asked to produce a copy of your driver’s license,
passport or other identifying documents in order to verify your identity. In addition, it may be necessary to verify your identity by
cross-referencing your identification information with a consumer report or other electronic databases. Other information or documents
may be required to open accounts for corporations and other entities. Federal law prohibits the Fund and other financial institutions
from opening a new account unless they receive the minimum identifying information described above. If a person fails to provide the information
requested, any application by that person to open a new account will be rejected. Moreover, if the transfer agent or the financial intermediary
is unable to verify the identity of a person based on information provided by that person, it may take additional steps including, but
not limited to, requesting additional information or documents from the person, closing the person’s account or reporting the matter
to the appropriate federal authorities. If your account is closed for this reason, your shares may be automatically redeemed at the net
asset value next determined. If the Fund’s net asset value has decreased since your purchase, you will lose money as a result of
this redemption. The Fund has also designated an anti-money laundering compliance officer.

Account Questions.
If you have any questions about your account or the services available, please call Calvert Shareholder Services at 1-800-368-2745 Monday
through Thursday, 9:00 a.m. to 5:30 p.m. (Eastern Time) and Friday, 9:00 a.m. to 5:00 p.m. (Eastern Time), or write to the transfer agent
(see back cover for address).

Calvert Mortgage Access Fund 36 Prospectus dated [______], 2022

Potential Conflicts of Interest

As a diversified global financial services firm, Morgan Stanley, the
parent company of the investment adviser, engages in a broad spectrum of activities, including financial advisory services, investment
management activities, lending, commercial banking, sponsoring and managing private investment funds, engaging in broker-dealer transactions
and principal securities, commodities and foreign exchange transactions, research publication and other activities. In the ordinary course
of its business, Morgan Stanley is a full-service investment banking and financial services firm and therefore engages in activities where
Morgan Stanley’s interests or the interests of its clients may conflict with the interests of a Fund or Portfolio, as applicable
(collectively, for purposes of this section, “Fund” or “Funds”). Morgan Stanley advises clients and sponsors,
manages or advises other investment funds and investment programs, accounts and businesses (collectively, together with any new or successor
Morgan Stanley funds, programs, accounts or businesses, (other than funds, programs, accounts or businesses sponsored, managed, or advised
by former direct or indirect subsidiaries of Eaton Vance Corp. (“Eaton Vance Investment Accounts”)), the “MS Investment
Accounts,” and, together with the Eaton Vance Investment Accounts, the ‘‘Affiliated Investment Accounts’’)
with a wide variety of investment objectives that in some instances may overlap or conflict with a Fund’s investment objectives
and present conflicts of interest. In addition, Morgan Stanley or the investment adviser may also from time to time create new or successor
Affiliated Investment Accounts that may compete with a Fund and present similar conflicts of interest. The discussion below enumerates
certain actual, apparent and potential conflicts of interest. There is no assurance that conflicts of interest will be resolved in favor
of Fund shareholders and, in fact, they may not be. Conflicts of interest not described below may also exist.

The discussions below with respect to actual, apparent and potential
conflicts of interest also may be applicable to or arise from the MS Investment Accounts whether or not specifically identified. For more
information about conflicts of interest, see the section entitled “Potential Conflicts of Interest” in the SAI.

Material
Non-public Information.
It is expected that confidential or material non-public information regarding an investment or potential
investment opportunity may become available to the investment adviser. If such information becomes available, the investment adviser may
be precluded (including by applicable law or internal policies or procedures) from pursuing an investment or disposition opportunity with
respect to such investment or investment opportunity. Morgan Stanley has established certain information barriers and other policies to
address the sharing of information between different businesses within Morgan Stanley. In limited circumstances, however, including for
purposes of managing business and reputational risk, and subject to policies and procedures and any applicable regulations, Morgan Stanley
personnel, including personnel of the investment adviser, on one side of an information barrier may have access to information and personnel
on the other side of the information barrier through “wall crossings.” The investment adviser faces conflicts of interest
in determining whether to engage in such wall crossings. Information obtained in connection with such wall crossings may limit or restrict
the ability of the investment adviser to engage in or otherwise effect transactions on behalf of the Fund(s) (including purchasing or
selling securities that the investment adviser may otherwise have purchased or sold for a Fund in the absence of a wall crossing).

Investments
by Morgan Stanley and its Affiliated Investment Accounts.
In serving in multiple capacities to Affiliated Investment Accounts,
Morgan Stanley, including the investment adviser and its investment teams, may have obligations to other clients or investors in Affiliated
Investment Accounts, the fulfillment of which may not be in the best interests of a Fund or its shareholders. A Fund’s investment
objectives may overlap with the investment objectives of certain Affiliated Investment Accounts. As a result, the members of an investment
team may face conflicts in the allocation of investment opportunities among a Fund and other investment funds, programs, accounts and
businesses advised by or affiliated with the investment adviser. Certain Affiliated Investment Accounts may provide for higher management
or incentive fees or greater expense reimbursements or overhead allocations, all of which may contribute to this conflict of interest
and create an incentive for the investment adviser to favor such other accounts. To seek to reduce potential conflicts of interest and
to attempt to allocate such investment opportunities in a fair and equitable manner, the investment adviser has implemented allocation
policies and procedures. These policies and procedures are intended to give all clients of the investment adviser, including the Fund(s),
fair access to investment opportunities consistent with the requirements of organizational documents, investment strategies, applicable
laws and regulations, and the fiduciary duties of the investment adviser.

Investments
by Separate Investment Departments.
The entities and individuals that provide investment-related services for the Fund and
certain other Eaton Vance Investment Accounts (the “Eaton Vance Investment Department”) may be different from the entities
and individuals that provide investment-related services to MS Investment Accounts (the “MS Investment Department” and, together
with the Eaton Vance Investment Department, the “Investment Departments”). Although Morgan Stanley has implemented information
barriers between the Investment Departments in accordance with

Calvert Mortgage Access Fund 37 Prospectus dated [______], 2022

internal policies and procedures, each Investment Department may engage
in discussions and share information and resources with the other Investment Department on certain investment-related matters. A MS Investment
Account could trade in advance of a Fund (and vice versa), might complete trades more quickly and efficiently than a Fund, and/or achieve
different execution than a Fund on the same or similar investments made contemporaneously, even when the Investment Departments shared
research and viewpoints that led to that investment decision. Any sharing of information or resources between the Investment Department
servicing the Fund and the MS Investment Department may result, from time to time, in a Fund simultaneously or contemporaneously seeking
to engage in the same or similar transactions as an account serviced by the other Investment Department and for which there are limited
buyers or sellers on specific securities, which could result in less favorable execution for the Fund than such account.

Payments
to Broker-Dealers and Other Financial Intermediaries.
The investment adviser and/or EVD may pay compensation, out of their
own funds and not as an expense of a Fund, to certain financial intermediaries (which may include affiliates of the investment adviser
and EVD), including recordkeepers and administrators of various deferred compensation plans, in connection with the sale, distribution,
marketing and retention of shares of the Fund and/or shareholder servicing. The prospect of receiving, or the receipt of, additional compensation,
as described above, by financial intermediaries may provide such financial intermediaries and their financial advisors and other salespersons
with an incentive to favor sales of shares of a Fund over other investment options with respect to which these financial intermediaries
do not receive additional compensation (or receive lower levels of additional compensation). These payment arrangements, however, will
not change the price that an investor pays for shares of a Fund or the amount that the Fund receives to invest on behalf of an investor.
Investors may wish to take such payment arrangements into account when considering and evaluating any recommendations relating to Fund
shares and should review carefully any disclosures provided by financial intermediaries as to their compensation. In addition, in certain
circumstances, the investment adviser may restrict, limit or reduce the amount of a Fund’s investment, or restrict the type of governance
or voting rights it acquires or exercises, where the Fund (potentially together with Morgan Stanley) exceeds a certain ownership interest,
or possesses certain degrees of voting or control or has other interests.

Morgan Stanley
Trading and Principal Investing Activities.
Notwithstanding anything to the contrary herein, Morgan Stanley will generally
conduct its sales and trading businesses, publish research and analysis, and render investment advice without regard for a Fund’s
holdings, although these activities could have an adverse impact on the value of one or more of the Fund’s investments, or could
cause Morgan Stanley to have an interest in one or more portfolio investments that is different from, and potentially adverse to, that
of a Fund.

Morgan Stanley’s
Investment Banking and Other Commercial Activities.
Morgan Stanley advises clients on a variety of mergers, acquisitions, restructuring,
bankruptcy and financing transactions. Morgan Stanley may act as an advisor to clients, including other investment funds that may compete
with a Fund and with respect to investments that a Fund may hold. Morgan Stanley may give advice and take action with respect to any of
its clients or proprietary accounts that may differ from the advice given, or may involve an action of a different timing or nature than
the action taken, by a Fund. Morgan Stanley may give advice and provide recommendations to persons competing with a Fund and/or any of
a Fund’s investments that are contrary to the Fund’s best interests and/or the best interests of any of its investments. Morgan
Stanley’s activities on behalf of its clients (such as engagements as an underwriter or placement agent) may restrict or otherwise
limit investment opportunities that may otherwise be available to a Fund.

Morgan Stanley may be engaged to act as a financial advisor to a company
in connection with the sale of such company, or subsidiaries or divisions thereof, may represent potential buyers of businesses through
its mergers and acquisition activities and may provide lending and other related financing services in connection with such transactions.
Morgan Stanley’s compensation for such activities is usually based upon realized consideration and is usually contingent, in substantial
part, upon the closing of the transaction. Under these circumstances, a Fund may be precluded from participating in a transaction with
or relating to the company being sold or participating in any financing activity related to merger or acquisition.

General Process
for Potential Conflicts.
All of the transactions described above involve the potential for conflicts of interest between the
investment adviser, related persons of the investment adviser and/or their clients. The Investment Advisers Act of 1940, as amended (the
“Advisers Act”) the 1940 Act and ERISA impose certain requirements designed to decrease the possibility of conflicts of interest
between an investment adviser and its clients. In some cases, transactions may be permitted subject to fulfillment of certain conditions.
Certain other transactions may be prohibited. In addition, the investment adviser has instituted policies and procedures designed to prevent
conflicts of interest from arising and, when they do arise, to ensure that it effects transactions for clients in a manner that is consistent
with its fiduciary duty to its clients and in accordance with applicable law. The investment adviser seeks to ensure that potential or
actual conflicts of interest are appropriately resolved taking into consideration the overriding best interests of the client.

Calvert Mortgage Access Fund 38 Prospectus dated [______], 2022

 

Additional Tax Information

The Fund declares distributions daily and ordinarily pays distributions
monthly. Different Classes may distribute different amounts. Your account will be credited with distributions beginning on the business
day after the day when the funds used to purchase your Fund shares are collected by the transfer agent. The Fund intends to distribute
any net realized capital gains (if any) annually. It may also be necessary, in order to qualify for favorable tax treatment and to avoid
any Fund-level tax, for a Fund to make a special income and/or capital gains distribution at the end of the calendar year. Distributions
of income and net short-term capital gains will be taxable as ordinary income. Distributions of net gains from investments held for more
than one year are generally taxable as long-term capital gains. The Fund expects that its distributions will consist primarily of ordinary
income. Taxes on distributions of capital gains are determined by how long a Fund owned (or is treated as having owned) the investments
that generated them, rather than how long a shareholder has owned his or her shares in a Fund. A Fund’s distributions will be taxable
as described above whether they are paid in cash or reinvested in additional shares.

Investors who purchase shares at a time when a Fund’s net asset
value reflects gains that are either unrealized or realized but undistributed will pay the full price for the shares and then may receive
some portion of the purchase price back as a taxable distribution. Certain distributions paid in January may be taxable to shareholders
as if received on December 31 of the prior year. A redemption of Fund shares, including an exchange for shares of another fund, generally
is a taxable transaction.

The net investment income of certain U.S. individuals, estates and trusts
is subject to a 3.8% Medicare contribution tax. For individuals, the tax is on the lesser of the “net investment income” and
the excess of modified adjusted gross income over $200,000 (or $250,000 if married filing jointly). Net investment income includes, among
other things, interest, dividends, and gross income and capital gains derived from passive activities and trading in securities or commodities.
Net investment income is reduced by deductions “properly allocable” to this income.

Investments in foreign securities may be subject to foreign withholding
taxes or other foreign taxes with respect to income (possibly including, in some cases, capital gains) which would decrease the Fund’s
yield on such securities. These taxes may be reduced or eliminated under the terms of an applicable tax treaty. Shareholders will generally
not be entitled to claim a credit or deduction with respect to foreign taxes paid by a Fund. In addition, investments in foreign securities
or foreign currencies may increase or accelerate a Fund’s recognition of ordinary income and may affect the timing or amount of
Fund distributions.

The Fund may be required to withhold, for U.S. federal income tax purposes,
a portion of the dividends, distributions and redemption proceeds payable to shareholders who fail to provide the Fund with their correct
taxpayer identification number or make required certifications, or who have been notified by the Internal Revenue Service (“IRS”)
that they are subject to backup withholding. Certain shareholders are exempt from backup withholding. Backup withholding is not an additional
tax and any amount withheld may be credited against a shareholder’s U.S. federal income tax liability.

Certain foreign entities may be subject to a 30% withholding tax on
dividend income paid under the Foreign Account Tax Compliance Act (“FATCA”). To avoid withholding, foreign financial institutions
subject to FATCA must agree to disclose to the relevant revenue authorities certain information regarding their direct and indirect U.S.
owners and other foreign entities must certify certain information regarding their direct and indirect U.S. owners to a Fund. In addition,
the IRS and the Department of Treasury have issued proposed regulations providing that these withholding rules will not be applicable
to the gross proceeds of share redemptions or capital gain dividends a Fund pays. For more detailed information regarding FATCA withholding
and compliance, please refer to the SAI.

Shareholders should consult with their tax advisors concerning the applicability
of federal, state, local and other taxes to an investment.

 

Calvert Mortgage Access Fund 39 Prospectus dated [______], 2022

 

Appendix A

The Calvert Principles for Responsible
Investment

We believe that most corporations deliver benefits to society, through
their products and services, creation of jobs, payment of taxes and the sum of their behaviors. As a responsible investor, Calvert Research
and Management seeks to invest in companies and other issuers that provide positive leadership in the areas of their operations and overall
activities that are material to improving long-term shareholder value and societal outcomes.

Calvert seeks to invest in issuers that balance the needs of financial
and nonfinancial stakeholders and demonstrate a commitment to the global commons, as well as to the rights of individuals and communities.

The Calvert Principles for Responsible Investment (Calvert Principles)
provide a framework for Calvert’s evaluation of investments and guide Calvert’s stewardship on behalf of clients through active
engagement with issuers. The Calvert Principles seek to identify companies and other issuers that operate in a manner that is consistent
with or promote:

Environmental Sustainability and Resource Efficiency

· Reduce the negative impact of operations and practices on the environment
· Manage water scarcity and ensure efficient and equitable access to clean sources
· Mitigate impact on all types of natural capital
· Diminish climate-related risks and reduce carbon emissions
· Drive sustainability innovation and resource efficiency through business operations or other activities, products and services

Equitable Societies and Respect for Human Rights

· Respect consumers by marketing products and services in a fair and ethical manner, maintaining integrity in customer relations and
ensuring the security of sensitive consumer data
· Respect human rights, respect culture and tradition in local communities and economies, and respect Indigenous Peoples’ Rights
· Promote diversity and gender equity across workplaces, marketplaces and communities
· Demonstrate a commitment to employees by promoting development, communication, appropriate economic opportunity and decent workplace
standards
· Respect the health and well-being of consumers and other users of products and services by promoting product safety

Accountable Governance and Transparency

· Provide responsible stewardship of capital in the best interests of shareholders and debtholders
· Exhibit accountable governance and develop effective boards or other governing bodies that reflect expertise and diversity of perspective
and provide oversight of sustainability risk and opportunity
· Include environmental and social risks, impacts and performance in material financial disclosures to inform shareholders and debtholders,
benefit stakeholders and contribute to strategy
· Lift ethical standards in all operations, including in dealings with customers, regulators and business partners
· Demonstrate transparency and accountability in addressing adverse events and controversies while minimizing risks and building trust

Through the application of the Calvert Principles, Calvert could have
no or limited exposure to issuers that:

· Demonstrate poor management of environmental risks or contribute significantly to local or global environmental problems.
· Demonstrate a pattern of employing forced, compulsory or child labor.
· Exhibit a pattern and practice directly or through the company’s supply chain of human rights violations or are complicit in
human rights violations committed by governments or security forces, including those that are under U.S. or international sanction for
human rights abuses.
· Exhibit a pattern and practice of violating the rights and protections of Indigenous Peoples.
· Demonstrate poor governance or engage in harmful or unethical practices.
· Manufacture tobacco products.
· Have significant and direct involvement in the manufacture of alcoholic beverages without taking significant steps to reduce the harmful
impact of these products.
· Have significant and direct involvement in gambling or gaming operations without taking significant steps to reduce the harmful impact
of these businesses.

Calvert Mortgage Access Fund 40 Prospectus dated [______], 2022

· Have significant and direct involvement in the manufacture of civilian handguns and/or automatic weapons marketed to civilians.
· Have significant and direct involvement in the manufacture of military weapons that violate international humanitarian law, including
cluster bombs, landmines, biochemical weapons, nuclear weapons, blinding laser weapons, or incendiary weapons.
· Use animals in product testing without countervailing social benefits such as the development of medical treatments to ease human
suffering and disease.

Calvert Mortgage Access Fund 41 Prospectus dated [______], 2022

 

Appendix B

Financial Intermediary Sales Charge Variations

Set forth below are the variations in or eliminations
of sales charges (“variations”) applicable to shares purchased through the noted financial intermediary. All variations described
below are applied by, and the responsibility of, the identified financial intermediary. Variations may apply to purchases, sales, exchanges
and reinvestments of Fund shares and a shareholder transacting in Fund shares through the intermediary identified below should read the
terms and conditions of the variations carefully. A variation that is specific to a particular financial intermediary is not applicable
to shares held directly with the Fund or through another intermediary.

Fund Purchases through Merrill Lynch

In all instances, it is the purchaser’s responsibility to notify
the Fund or the purchaser’s financial intermediary at the time of purchase of any relationship or other facts qualifying the purchaser
for sales charge waivers or discounts. For waivers and discounts not available
through a particular intermediary, shareholders will have to purchase Fund shares directly from the Fund or through another intermediary
to receive these waivers or discounts.

Shareholders purchasing Fund shares through a Merrill Lynch platform
or account are eligible only for the following sales charge waivers (front-end sales charge waivers and contingent deferred, or back-end,
sales charge waivers) and discounts, which may differ from those disclosed elsewhere in this Prospectus or SAI.

Front-end Sales Load Waivers on Class A Shares available at Merrill
Lynch

· Employer-sponsored retirement, deferred compensation and employee benefit plans (including health savings accounts) and trusts used
to fund those plans, provided that the shares are not held in a commission-based brokerage account and shares are held for the benefit
of the plan
· Shares purchased by a 529 Plan (does not include 529 Plan units or 529-specific share classes or equivalents)
· Shares purchased through a Merrill Lynch affiliated investment advisory program
· Shares exchanged due to the holdings moving from a Merrill Lynch affiliated investment advisory program to a Merrill Lynch brokerage
(non-advisory) account pursuant to Merrill Lynch’s policies relating to sales load discounts and waivers
· Shares purchased by third party investment advisors on behalf of their advisory clients through Merrill Lynch’s platform
· Shares of funds purchased through the Merrill Edge Self-Directed platform (if applicable)
· Shares purchased through reinvestment of capital gains distributions and dividend reinvestment when purchasing shares of the same
fund (but not any other fund within the fund family)
· Shares exchanged from Class C (i.e. level-load) shares of the same fund pursuant to Merrill Lynch’s policies relating to sales
load discounts and waivers
· Employees and registered representatives of Merrill Lynch or its affiliates and their family members
· Directors or Trustees of the Fund, and employees of the Fund’s investment adviser or any of its affiliates, as described in
the this prospectus
· Eligible shares purchased from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within
90 days following the redemption, (2) the redemption and purchase occur in the same account, and (3) redeemed shares were subject to a
front-end or deferred sales load (known as Rights of Reinstatement). Automated transactions (i.e. systematic purchases and withdrawals)
and purchases made after shares are automatically sold to pay Merrill Lynch’s account maintenance fees are not eligible for reinstatement

CDSC Waivers on Class A and Class C Shares available at Merrill
Lynch

· Death or disability of the shareholder
· Shares sold as part of a systematic withdrawal plan as described in the Fund’s prospectus
· Return of excess contributions from an IRA Account
· Shares sold as part of a required minimum distribution for IRA and retirement accounts pursuant to the Internal Revenue Code
· Shares sold to pay Merrill Lynch fees but only if the transaction is initiated by Merrill Lynch
· Shares acquired through a right of reinstatement
· Shares held in retirement brokerage accounts, that are exchanged for a lower cost share class due to transfer to certain fee based
accounts or platforms (applicable to Class A and C shares only)
· Shares received through an exchange due to the holdings moving from a Merrill Lynch affiliated investment advisory program to a Merrill
Lynch brokerage (non-advisory) account pursuant to Merrill Lynch’s policies relating to sales load discounts and waivers

Calvert Mortgage Access Fund 42 Prospectus dated [______], 2022

 

Front-end load Discounts Available at Merrill Lynch: Breakpoints,
Rights of Accumulation & Letters of Intent

· Breakpoints as described in this prospectus
· Rights of Accumulation (ROA) which entitle shareholders to breakpoint discounts as described in the Fund’s prospectus will be
automatically calculated based on the aggregated holding of fund family assets held by accounts (including 529 program holdings, where
applicable) within the purchaser’s household at Merrill Lynch. Eligible fund family assets not held at Merrill Lynch may be included
in the ROA calculation only if the shareholder notifies his or her financial advisor about such assets
· Letters of Intent (LOI) which allow for breakpoint discounts based on anticipated purchases within a fund family, through Merrill
Lynch, over a 13-month period of time (if applicable)

Calvert Mortgage Access Fund 43 Prospectus dated [______], 2022

Fund Purchases through Ameriprise Financial (Class A Sales Charge
Waivers)

The following information applies to Class A share purchases if you
have an account with or otherwise purchase Fund shares through Ameriprise Financial:

Effective January 15, 2021, shareholders purchasing Fund shares through
an Ameriprise Financial retail brokerage account are eligible for the following front-end sales charge waivers, which may differ from
those disclosed elsewhere in this Prospectus or in the SAI.

· Employer-sponsored retirement plans (e.g., 401(k) plans 457 plans, employer-sponsored 403(b) plans, profit sharing and money purchase
pension plans and defined benefit plans). For purposes of this provision, employer-sponsored retirement plans do not include SEP IRAs,
Simple IRAs or SAR-SEPs.
· Shares purchased through reinvestment of capital gains distributions and dividend reinvestment when purchasing shares of the same
Fund (but not any other fund within the same fund family).
· Shares exchanged from Class C shares of the same fund in the month of or following the 7-year anniversary of the purchase date. To
the extent that this Prospectus elsewhere provides for a waiver with respect to exchanges of Class C shares or conversion of Class C shares
following a shorter holding period, that waiver will apply.
· Employees and registered representatives of Ameriprise Financial or its affiliates and their immediate family members.
· Shares purchased by or through qualified accounts (including IRAs, Coverdell Education Savings Accounts, 401(k)s, 403(b) TSCAs subject
to ERISA and defined benefit plans) that are held by a covered family member, defined as an Ameriprise financial advisor and/or the advisor’s
spouse, advisor’s lineal ascendant (mother, father, grandmother, grandfather, great grandmother, great grandfather), advisor’s
lineal descendant (son, step-son, daughter, step-daughter, grandson, granddaughter, great grandson, great granddaughter) or any spouse
of a covered family member who is a lineal descendant.
· Shares purchased from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within 90 days following
the redemption, (2) the redemption and purchase occur in the same account, and (3) redeemed shares were subject to a front-end or deferred
sales load (i.e. Rights of Reinstatement).

Calvert Mortgage Access Fund 44 Prospectus dated [______], 2022

Fund Purchases through Morgan Stanley Wealth Management

Effective July 1, 2018, shareholders purchasing Fund shares through
a Morgan Stanley Wealth Management transactional brokerage account will be eligible only for the following front-end sales charge waivers
with respect to Class A shares, which may differ from and may be more limited than those disclosed elsewhere in this Prospectus or SAI.

Front-end Sales Charge Waivers on Class A Shares available at Morgan
Stanley Wealth Management

· Employer-sponsored retirement plans (e.g., 401(k) plans, 457 plans, employer-sponsored 403(b) plans, profit sharing and money purchase
pension plans and defined benefit plans). For purposes of this provision, employer-sponsored retirement plans do not include SEP IRAs,
Simple IRAs, SAR-SEPs or Keogh plans
· Morgan Stanley employee and employee-related accounts according to Morgan Stanley’s account linking rules
· Shares purchased through reinvestment of dividends and capital gains distributions when purchasing shares of the same fund
· Shares purchased through a Morgan Stanley self-directed brokerage account
· Class C (i.e., level-load) shares that are no longer subject to a contingent deferred sales charge and are converted to Class A shares
of the same fund pursuant to Morgan Stanley Wealth Management’s share class conversion program
· Shares purchased from the proceeds of redemptions within the same fund family, provided (i) the repurchase occurs within 90 days following
the redemption, (ii) the redemption and purchase occur in the same account, and (iii) redeemed shares were subject to a front-end or deferred
sales charge.

Calvert Mortgage Access Fund 45 Prospectus dated [______], 2022

Fund Purchases through Raymond James & Associates, Inc., Raymond
James Financial Services, Inc. and each entity’s affiliates (“Raymond James”)

Effective March 1, 2019, shareholders purchasing fund shares through
a Raymond James platform or account, or through an introducing broker-dealer or independent registered investment adviser for which Raymond
James provides trade execution, clearance, and/or custody services, will be eligible only for the following load waivers (front-end sales
charge waivers and contingent deferred, or back-end, sales charge waivers) and discounts, which may differ from those disclosed elsewhere
in this fund’s prospectus or SAI.

Front-end sales load waivers on Class A shares available at Raymond
James

· Shares purchased in an investment advisory program.
· Shares purchased within the same fund family through a systematic reinvestment of capital gains and dividend distributions.
· Employees and registered representatives of Raymond James or its affiliates and their family members as designated by Raymond James.
· Shares purchased from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within 90 days following
the redemption, (2) the redemption and purchase occur in the same account, and (3) redeemed shares were subject to a front-end or deferred
sales load (known as Rights of Reinstatement).
· A shareholder in the Fund’s Class C shares will have their shares converted at net asset value to Class A shares (or the appropriate
share class) of the Fund if the shares are no longer subject to a CDSC and the conversion is in line with the policies and procedures
of Raymond James.

CDSC Waivers on Classes A and C shares available at Raymond James

· Death or disability of the shareholder.
· Shares sold as part of a systematic withdrawal plan as described in the fund’s prospectus.
· Return of excess contributions from an IRA Account.
· Shares sold as part of a required minimum distribution for IRA and retirement accounts due to the shareholder reaching the qualified
age based on applicable IRS regulations as described in the fund’s prospectus.
· Shares sold to pay Raymond James fees but only if the transaction is initiated by Raymond James.
· Shares acquired through a right of reinstatement.

Front-end load discounts available at Raymond James: breakpoints,
rights of accumulation, and/or letters of intent

· Breakpoints as described in this prospectus.
· Rights of accumulation which entitle shareholders to breakpoint discounts will be automatically calculated based on the aggregated
holding of fund family assets held by accounts within the purchaser’s household at Raymond James. Eligible fund family assets not
held at Raymond James may be included in the calculation of rights of accumulation only if the shareholder notifies his or her financial
advisor about such assets.
· Letters of intent which allow for breakpoint discounts based on anticipated purchases within a fund family, over a 13-month time period.
Eligible fund family assets not held at Raymond James may be included in the calculation of letters of intent only if the shareholder
notifies his or her financial advisor about such assets.

Calvert Mortgage Access Fund 46 Prospectus dated [______], 2022

Fund Purchases through Janney Montgomery Scott LLC (“Janney”)

Effective May 1, 2020, if you purchase fund shares through a Janney
brokerage account, you will be eligible for the following load waivers (front-end sales charge waivers and contingent deferred sales charge
(“CDSC”), or back-end sales charge waivers) and discounts, which may differ from those disclosed elsewhere in this fund’s
Prospectus or SAI.

Front-end sales charge* waivers on Class A shares available at
Janney

· Shares purchased through reinvestment of capital gains distributions and dividend reinvestment when purchasing shares of the same
fund (but not any other fund within the fund family).
· Shares purchased by employees and registered representatives of Janney or its affiliates and their family members as designated by
Janney.
· Shares purchased from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within ninety (90)
days following the redemption, (2) the redemption and purchase occur in the same account, and (3) redeemed shares were subject to a front-end
or deferred sales load (i.e., right of reinstatement).
· Employer-sponsored retirement plans (e.g., 401(k) plans, 457 plans, employer-sponsored 403(b) plans, profit sharing and money purchase
pension plans and defined benefit plans). For purposes of this provision, employer-sponsored retirement plans do not include SEP IRAs,
Simple IRAs, SAR-SEPs or Keogh plans.
· Shares acquired through a right of reinstatement.
· Class C shares that are no longer subject to a contingent deferred sales charge and are converted to Class A shares of the same fund
pursuant to Janney’s policies and procedures.

CDSC waivers on Class A and C shares available at Janney

· Shares sold upon the death or disability of the shareholder.
· Shares sold as part of a systematic withdrawal plan as described in the fund’s Prospectus.
· Shares purchased in connection with a return of excess contributions from an IRA account.
· Shares sold as part of a required minimum distribution for IRA and other retirement accounts if the redemption is taken in or after
the year the shareholder reaches qualified age based on applicable IRS regulations.
· Shares sold to pay Janney fees but only if the transaction is initiated by Janney.
· Shares acquired through a right of reinstatement.
· Shares exchanged into the same share class of a different fund.

Front-end sales charge* discounts available at Janney: breakpoints,
rights of accumulation and/or letters of intent

· Breakpoints as described in the fund’s Prospectus.
· Rights of accumulation (“ROA”), which entitle shareholders to breakpoint discounts, will be automatically calculated based
on the aggregated holding of fund family assets held by accounts within the purchaser’s household at Janney. Eligible fund family
assets not held at Janney may be included in the ROA calculation only if the shareholder notifies his or her financial advisor about such
assets.
· Letters of intent which allow for breakpoint discounts based on anticipated purchases within a fund family, over a 13-month time period.
Eligible fund family assets not held at Janney Montgomery Scott may be included in the calculation of letters of intent only if the shareholder
notifies his or her financial advisor about such assets.

 

* Also referred to as an “initial sales charge.”

 

Calvert Mortgage Access Fund 47 Prospectus dated [______], 2022

Fund Purchases through Oppenheimer & Co. Inc. (“Oppenheimer”)

Effective May 1, 2020, shareholders purchasing Fund shares through an
Oppenheimer platform or account are eligible only for the following load waivers (front-end sales charge waivers and contingent deferred,
or back-end, sales charge waivers) and discounts, which may differ from those disclosed elsewhere in this Fund’s prospectus or SAI.

Front-end Sales Load Waivers on Class A Shares available at Oppenheimer

· Employer-sponsored retirement, deferred compensation and employee benefit plans (including health savings accounts) and trusts used
to fund those plans, provided that the shares are not held in a commission-based brokerage account and shares are held for the benefit
of the plan.
· Shares purchased by or through a 529 Plan.
· Shares purchased through a Oppenheimer affiliated investment advisory program.
· Shares purchased through reinvestment of capital gains distributions and dividend reinvestment when purchasing shares of the same
fund (but not any other fund within the fund family).
· Shares purchased from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within 90 days following
the redemption, (2) the redemption and purchase occur in the same account, and (3) redeemed shares were subject to a front-end or deferred
sales load (known as Rights of Restatement).
· A shareholder in the Fund’s Class C shares will have their shares converted at net asset value to Class A shares (or the appropriate
share class) of the Fund if the shares are no longer subject to a contingent deferred sales charge (CDSC) and the conversion is in line
with the policies and procedures of Oppenheimer.
· Employees and registered representatives of Oppenheimer or its affiliates and their family members.
· Directors or Trustees of the Fund, and employees of the Fund’s investment adviser or any of its affiliates, as described in
this prospectus.

CDSC Waivers on A and C Shares available at Oppenheimer

· Death or disability of the shareholder.
· Shares sold as part of a systematic withdrawal plan as described in the Fund’s prospectus.
· Return of excess contributions from an IRA Account.
· Shares sold as part of a required minimum distribution for IRA and retirement accounts due to the shareholder reaching the qualified
age based on IRS regulations as described in the prospectus.
· Shares sold to pay Oppenheimer fees but only if the transaction is initiated by Oppenheimer.
· Shares acquired through a right of reinstatement.

Front-end load Discounts Available at Oppenheimer: Breakpoints,
Rights of Accumulation & Letters of Intent

· Breakpoints as described in this prospectus.
· Rights of Accumulation (ROA) which entitle shareholders to breakpoint discounts will be automatically calculated based on the aggregated
holding of fund family assets held by accounts within the purchaser’s household at Oppenheimer. Eligible fund family assets not
held at Oppenheimer may be included in the ROA calculation only if the shareholder notifies his or her financial advisor about such assets.

 

Calvert Mortgage Access Fund 48 Prospectus dated [______], 2022

Policies Regarding Transactions Through Edward D. Jones &
Co., L.P. (“Edward Jones”)

The following information has been provided by Edward Jones:

Effective on or after March 1, 2021, the following information supersedes
prior information with respect to transactions and positions held in fund shares through an Edward Jones system. Clients of Edward Jones
(also referred to as “shareholders”) purchasing fund shares on the Edward Jones commission and fee-based platforms are eligible
only for the following sales charge discounts (also referred to as “breakpoints”) and waivers, which can differ from discounts
and waivers described elsewhere in the mutual fund prospectus or statement of additional information (“SAI”) or through another
broker-dealer. In all instances, it is the shareholder’s responsibility to inform Edward Jones at the time of purchase of any relationship,
holdings of fund family or other facts qualifying the purchaser for discounts or waivers. Edward Jones can ask for documentation from
the shareholder of such circumstance. Shareholders should contact Edward Jones if they have questions regarding their eligibility for
these discounts and waivers.

Breakpoints

· Breakpoint pricing, otherwise known as volume pricing, at dollar thresholds as described in the prospectus.

Rights of Accumulation (“ROA”)

· The applicable sales charge on a purchase of Class A shares is determined by taking into account all share classes (except certain
money market funds and any assets held in group retirement plans) of the mutual fund family held by the shareholder or in an account grouped
by Edward Jones with other accounts for the purpose of providing certain pricing considerations (“pricing groups”). If grouping
assets as a shareholder, this includes all share classes held on the Edward Jones platform and/or held on another platform. The inclusion
of eligible fund family assets in the ROA calculation is dependent on the shareholder notifying Edward Jones of such assets at the time
of calculation. Money market funds are included only if such shares were sold with a sales charge at the time of purchase or acquired
in exchange for shares purchased with a sales charge.
· The employer maintaining a SEP IRA plan and/or SIMPLE IRA plan may elect to establish or change ROA for the IRA accounts associated
with the plan to a plan-level grouping as opposed to including all share classes at a shareholder or pricing group level.
· ROA is determined by calculating the higher of cost minus redemptions or market value (current shares x NAV).

Letter of Intent (“LOI”)

· Through a LOI, shareholders can receive the sales charge and breakpoint discounts for purchases shareholders intend to make over a
13-month period from the date Edward Jones receives the LOI. The LOI is determined by calculating the higher of cost or market value of
qualifying holdings at LOI initiation in combination with the value that the shareholder intends to buy over a 13-month period to calculate
the front-end sales charge and any breakpoint discounts. Each purchase the shareholder makes during that 13-month period will receive
the sales charge and breakpoint discount that applies to the total amount. If during the 13-month period the shareholder redeems any of
the shares purchased pursuant to a LOI, the value of the redeemed shares will not be included for purposes of satisfying the LOI. The
inclusion of eligible fund family assets in the LOI calculation is dependent on the shareholder notifying Edward Jones of such assets
at the time of calculation. Purchases made before the LOI is received by Edward Jones are not adjusted under the LOI and will not reduce
the sales charge previously paid. Sales charges will be adjusted if LOI is not met.
· If the employer maintaining a SEP IRA plan and/or SIMPLE IRA plan has elected to establish or change ROA for the IRA accounts associated
with the plan to a plan-level grouping, LOIs will also be at the plan-level and may only be established by the employer.

Front-end Sales Charge Waivers

Sales charges are waived for the following shareholders and
in the following situations:

· Associates of Edward Jones and its affiliates and their family members who are in the same pricing group (as determined by Edward
Jones under its policies and procedures) as the associate. This waiver will continue for the remainder of the associate’s life if the
associate retires from Edward Jones in good-standing and remains in good standing pursuant to Edward Jones’ policies and procedures.
· Shares purchased in an Edward Jones fee-based program.
· Shares purchased through reinvestment of capital gains distributions and dividend reinvestment.
· Shares purchased from the proceeds of redeemed shares of the same fund family so long as the following conditions are met: 1) the
proceeds are from the sale of shares within 60 days of the purchase, and 2) the sale and purchase are made in the same share class and
the same account or the purchase is made in an individual retirement account with proceeds from liquidations in a non-retirement account.

Calvert Mortgage Access Fund 49 Prospectus dated [______], 2022

· Shares exchanged into Class A shares from another share class so long as the exchange is into the same fund and was initiated at the
discretion of Edward Jones. Edward Jones is responsible for any remaining Contingent Deferred Sales Charge (“CDSC”) due to
the fund company or its affiliate, if applicable. Any future purchases are subject to the applicable sales charge as disclosed in the
prospectus.
· Exchanges from Class C shares to Class A shares of the same fund, generally, in the 84th month following the anniversary of the purchase
date or earlier at the discretion of Edward Jones.

CDSC Waivers

If the shareholder purchases shares that are subject to a
CDSC and those shares are redeemed before the CDSC is expired, the shareholder is responsible to pay the CDSC except in the following
conditions:

· The death or disability of the shareholder.
· Systematic withdrawals with up to 10% per year of the account value.
· Return of excess contributions from an Individual Retirement Account (IRA).
· Shares sold as part of a required minimum distribution for IRA and retirement accounts if the redemption is taken in or after the
year the shareholder reaches qualified age based on applicable IRS regulations.
· Shares sold to pay Edward Jones fees or costs in such cases where the transaction is initiated by Edward Jones. Edward Jones is responsible
for any remaining CDSC due to the fund company or its affiliate, if applicable.
· Shares exchanged in an Edward Jones fee-based program. Edward Jones is responsible for any remaining CDSC due to the fund company
or its affiliate, if applicable.
· Shares acquired through NAV reinstatement.
· Shares redeemed at the discretion of Edward Jones for Minimum Balances as described below.

 

******************************************************************************

Other Important Information Regarding Transactions Through Edward
Jones

Minimum Purchase Amounts

· Initial purchase minimum: $250
· Subsequent purchase minimum: none

Minimum Balances

· Edward Jones has the right to redeem at its discretion fund holdings with a balance of $250 or less. The following are examples of
accounts that are not included in this policy:
· A fee-based account held on an Edward Jones platform
· A 529 account held on an Edward Jones platform
· An account with an active systematic investment plan or LOI

Exchanging Share Classes

· At any time it deems necessary, Edward Jones has the authority to exchange at NAV a shareholder’s holdings in a fund to Class A shares
of the same fund. Edward Jones is responsible for any remaining CDSC due to the fund company or its affiliate, if applicable. Any future
purchases are subject to the applicable sales charge as disclosed in the prospectus.

 

Calvert Mortgage Access Fund 50 Prospectus dated [______], 2022

Fund Purchases through D.A. Davidson & Co. (“D.A.
Davidson”)

Effective 5/1/2020, shareholders purchasing fund shares including existing
fund shareholders through a D.A. Davidson platform or account, or through an introducing broker-dealer or independent registered investment
advisor for which D.A. Davidson provides trade execution, clearance, and/or custody services, will be eligible for the following sales
charge waivers (front-end sales charge waivers and contingent deferred, or back-end, sales charge waivers) and discounts, which may differ
from those disclosed elsewhere in this prospectus or SAI.

Front-End Sales Charge Waivers on Class A Shares available at D.A.
Davidson

· Shares purchased within the same fund family through a systematic reinvestment of capital gains and dividend distributions.
· Employees and registered representatives of D.A. Davidson or its affiliates and their family members as designated by D.A. Davidson.
· Shares purchased from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within 90 days following
the redemption, (2) the redemption and purchase occur in the same account, and (3) redeemed shares were subject to a front-end or deferred
sales charge (known as Rights of Reinstatement).
· A shareholder in the Fund’s Class C shares will have their shares converted at net asset value to Class A shares (or the appropriate
share class) of the Fund if the shares are no longer subject to a CDSC and the conversion is consistent with D.A. Davidson’s policies
and procedures.

CDSC Waivers on Classes A and C shares available at D.A. Davidson

· Death or disability of the shareholder.
· Shares sold as part of a systematic withdrawal plan as described in the fund’s prospectus.
· Return of excess contributions from an IRA Account.
· Shares sold as part of a required minimum distribution for IRA or other qualifying retirement accounts as described in the fund’s
prospectus beginning in the calendar year the shareholder turns age 72.
· Shares acquired through a right of reinstatement.

Front-end sales charge discounts available at D.A. Davidson: breakpoints,
rights of accumulation and/or letters of intent CDSC Waivers on Classes A and C shares available at D.A. Davidson

· Breakpoints as described in this prospectus.
· Rights of accumulation which entitle shareholders to breakpoint discounts will be automatically calculated based on the aggregated
holding of fund family assets held by accounts within the purchaser’s household at D.A. Davidson. Eligible fund family assets not
held at D.A. Davidson may be included in the calculation of rights of accumulation only if the shareholder notifies his or her financial
advisor about such assets.
· Letters of intent which allow for breakpoint discounts based on anticipated purchases within a fund family, over a 13-month time period.
Eligible fund family assets not held at D.A. Davidson may be included in the calculation of letters of intent only if the shareholder
notifies his or her financial advisor about such assets.

Calvert Mortgage Access Fund 51 Prospectus dated [______], 2022

Fund Purchases through Robert W. Baird & Co. Incorporated
(“Baird”)

Effective June 15, 2020, shareholders purchasing fund shares through
a Baird platform or account will only be eligible for the following sales charge waivers (front-end sales charge waivers and CDSC waivers)
and discounts, which may differ from those disclosed elsewhere in this prospectus or the SAI

Front-End Sales Charge Waivers on Class A shares Available at Baird

· Shares purchased through reinvestment of capital gains distributions and dividend reinvestment when purchasing share of the same fund
· Share purchase by employees and registers representatives of Baird or its affiliate and their family members as designated by Baird
· Shares purchase from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within 90 days following
the redemption, (2) the redemption and purchase occur in the same accounts, and (3) redeemed shares were subject to a front-end or deferred
sales charge (known as rights of reinstatement)
· A shareholder in the Fund’s Class C Shares will have their shares converted at net asset value to Class A shares of the Fund
if the shares are no longer subject to CDSC and the conversion is in line with the policies and procedures of Baird
· Employer-sponsored retirement plans or charitable accounts in a transactional brokerage account at Baird, including 401(k) plans,
457 plans, employer-sponsored 403(b) plans, profit sharing and money purchase pension plans and defined benefit plans. For purposes of
this provision, employer-sponsored retirement plans do not include SEP IRAs, Simple IRAs or SAR-SEPs

CDSC Waivers on Class A and C shares Available at Baird

· Shares sold due to death or disability of the shareholder
· Shares sold as part of a systematic withdrawal plan as described in the Fund’s Prospectus
· Shares sold due to returns of excess contributions from an IRA Account
· Shares sold as part of a required minimum distribution for IRA and retirement accounts
· Shares sold to pay Baird fees but only if the transaction is initiated by Baird
· Shares acquired through a right of reinstatement

Front-End Sales Charge Discounts Available at Baird: Breakpoints
and/or Rights of Accumulations

· Breakpoints as described in this prospectus
· Rights of accumulations which entitles shareholders to breakpoint discounts will be automatically calculated based on the aggregated
holding of fund family assets held by accounts within the purchaser’s household at Baird. Eligible fund family assets not held at
Baird may be included in the rights of accumulations calculation only if the shareholder notifies his or her financial advisor about such
assets
· Letters of Intent (LOI) allow for breakpoint discounts based on anticipated purchases of fund family assets through Baird, over a
13-month period of time

 

Calvert Mortgage Access Fund 52 Prospectus dated [______], 2022

Waivers Specific to Stifel, Nicolaus & Company, Incorporated
(“Stifel”)

Effective July 1, 2020, shareholders purchasing Fund shares through
a Stifel platform or account or who own shares for which Stifel or an affiliate is the broker-dealer of record are eligible for the following
additional sales charge waiver:

Front-End Sales Load Waiver on Class A shares

· Class C shares that have been held for more than seven (7) years will be converted to Class A shares of the same Fund at net asset
value pursuant to Stifel’s policies and procedures.

Calvert Mortgage Access Fund 53 Prospectus dated [______], 2022

 

More Information

About
the Fund:
More information is available in the Statement of Additional Information. The Statement of Additional Information
is incorporated by reference into this Prospectus. Additional information about the Fund’s investments will be available in
the annual and semiannual reports (collectively, the “reports”). In the annual report, you will find a discussion of the market
conditions and investment strategies that significantly affected the Fund’s performance during the past fiscal year. You may obtain
free copies of the Statement of Additional Information and the reports on Calvert’s website at www.calvert.com or by contacting
the principal underwriter:

Eaton Vance Distributors, Inc.
Two International Place
Boston, MA 02110
1-800-368-2745
website: www.calvert.com

Information about the Fund (including the Statement of Additional
Information and reports) is available on the EDGAR database on the SEC’s website at www.sec.gov, and copies of this information
may be obtained, after paying a duplicating fee, by electronic request at the following email address: publicinfo@sec.gov.

Beginning on January 1, 2021, as permitted by regulations adopted
by the Securities and Exchange Commission, paper copies of the Fund’s annual and semi-annual shareholder reports are no longer being
sent by mail unless you specifically request paper copies of the reports. Instead, the reports are being made available on the Fund’s
website (http://www.calvert.com/prospectus), and you will be notified each time a report is posted and provided with a website address
to access the report. You may elect to receive all future Fund shareholder reports in paper free of charge at any time. If you are a direct
investor, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling 1-800- 368-2745.
If you own these shares through a financial intermediary, you must contact your financial intermediary to elect to continue to receive
paper copies of your shareholder reports. If you are a direct investor, you may elect to receive shareholder reports and other communications
from the Fund electronically by signing up for e-Delivery at calvert.com. If you own your shares through a financial intermediary (such
as a broker-dealer or bank), you must contact your financial intermediary to sign up.

Shareholder
Inquiries:
You can obtain more information from Calvert Shareholder Services or the Fund transfer agent, DST Asset Manager
Solutions, Inc. If you own shares and would like to add to, redeem from or change your account, please write or call below:

Regular Mailing Address:
Calvert Funds
P.O. Box 219544
Kansas City, MO  64121-9544
  Overnight Mailing Address:
Calvert Funds
430 West 7th Street
Kansas City, MO  64105-1407
  Phone Number:
1-800-368-2745
Monday – Thursday
9:00 a.m. – 5:30 p.m. ET
Friday
9:00 a.m. – 5:00 p.m. ET

 

The Fund’s Investment Company Act No. is 811-03334.  
[  ] [  ].[  ].[  ] © 2022 Calvert Research and Management

 

Printed on recycled paper.

 

SUBJECT TO COMPLETION   ____________, 2022

 

STATEMENT OF
ADDITIONAL INFORMATION
[ ], 2022

 

 

Calvert Mortgage Access Fund

Class A Shares – [ ]  Class C Shares
– [ ]  Class I Shares – [ ]  Class R6 Shares – [ ] 

1825 Connecticut Avenue NW, Suite 400
Washington, DC 20009
1-800-368-2745

This Statement of Additional Information (“SAI”) provides
general information about the Fund. The Fund is a non-diversified, open-end management investment company. The Fund is a series of The Calvert
Fund. Capitalized terms used in this SAI and not otherwise defined have the meanings given to them in the Prospectus.

This SAI contains additional information about:

  Page     Page
Strategies and Risks 2   Sales Charges 19
Investment Restrictions 5   Disclosure of Portfolio Holdings and Related Information 21
Management and Organization 6   Taxes 22
Investment Advisory and Administrative Services 13   Portfolio Securities Transactions 32
Other Service Providers 16   Potential Conflicts of Interest 34
Calculation of Net Asset Value 16   Financial Statements 41
Purchasing and Redeeming Shares 17   Additional Information About Investment Strategies and Risks 41

 

Appendix A: Class A Fees and Ownership 91   Appendix E: Ratings 95
Appendix B: Class C Fees and Ownership 92   Appendix F: Calvert Funds Proxy Voting Policy and Procedures 104
Appendix C: Class I Ownership 93   Appendix G: Adviser Proxy Voting Policies and Procedures 106
Appendix D: Class R6 Ownership 94      

This SAI is NOT a prospectus and is authorized for distribution
to prospective investors only if preceded or accompanied by the Fund Prospectus dated [ ], 2022, as supplemented from time to time, which
is incorporated herein by reference. This SAI should be read in conjunction with the Prospectus, which may be obtained by calling 1-800-368-2745.

© 2022 Calvert
Research and Management

 

Definitions

The following terms that may be used in this SAI have the meaning
set forth below:

“1940 Act” means the Investment Company Act of 1940,
as amended;

“1933 Act” means the Securities Act of 1933, as amended;

“Board” means Board of Trustees or Board of Directors,
as applicable;

“Calvert family of funds” means all registered investment
companies advised or administered by Calvert Research and Management (“CRM”, “Calvert”, the “Adviser”
or the “investment adviser”);

“Calvert funds” means the mutual funds advised by CRM;

“CEA” means Commodity Exchange Act;

“CFTC” means the Commodity Futures Trading Commission;

“Code” means the Internal Revenue Code of 1986, as
amended;

“Exchange” means the New York Stock Exchange;

“FINRA” means the Financial Industry Regulatory Authority;

“Fund” means the Fund or Funds listed on the cover
of this SAI unless stated otherwise;

“investment adviser” means the investment adviser identified
in the prospectus and, with respect to the implementation of the Fund’s investment strategies (including as described under “Taxes”)
and portfolio securities transactions, any sub-adviser identified in the prospectus to the extent that the sub-adviser has discretion
to perform the particular duties;

“IRS” means the Internal Revenue Service;

“SEC” means the U.S. Securities and Exchange Commission;
and

“Trust” means The Calvert Fund, of which the Fund is a series.

STRATEGIES AND RISKS

The Fund prospectus identifies the types of investments in which the
Fund will principally invest in seeking its investment objective(s) and the principal risks associated therewith. The categories checked
in the table below are all of the investments the Fund is permitted to make, including its principal investments and the investment practices
the Fund (either directly or through one or more Portfolios as may be described in the prospectus) is permitted to engage in. To the extent
that an investment type or practice listed below is not identified in the Fund prospectus as a principal investment strategy, the Fund
generally expects to invest less than 5% of its total assets in such investment type. The Fund may hold a security or other instrument
that is not otherwise identified as permissible if it is received through a corporate action. If a particular investment type or practice
that is checked and listed below but not referred to in the prospectus becomes a more significant part of the Fund’s strategy, the
prospectus may be amended to disclose that investment type or practice. Information about the various investment types and practices and
the associated risks checked below is included in alphabetical order in this SAI under “Additional Information about Investment
Strategies and Risks.”

Investment Type Permitted for or Relevant to the Fund
Asset-Backed Securities (“ABS”)
Auction Rate Securities
Build America Bonds  
Call and Put Features on Securities
Collateralized Mortgage Obligations (“CMOs”)  
Commercial Mortgage-Backed Securities (“CMBS”)
Commodity-Related Investments  
Common Stocks  
Contingent Convertible Securities  
Convertible Securities
Credit Linked Securities  

Calvert Mortgage Access Fund 2 SAI dated [______], 2022

 

 

Investment Type Permitted for or Relevant to the Fund
Derivative Instruments and Related Risks
Derivative-Linked and Commodity-Linked Hybrid Instruments  
Direct Investments  
Emerging Market Investments
Equity Investments  
Equity-Linked Securities  
Event-Linked Instruments  
Exchange-Traded Funds (“ETFs”)
Exchange-Traded Notes (“ETNs”)  
Fixed-Income Securities
Foreign Currency Transactions
Foreign Investments
Forward Foreign Currency Exchange Contracts
Forward Rate Agreements
Futures Contracts
High Social Impact Investments  
Hybrid Securities
Illiquid Investments
Indexed Securities
Inflation-Indexed (or Inflation-Linked) Bonds
Junior Loans
Liquidity or Protective Put Agreements  
Loans
Lower Rated Investments
Master Limited Partnerships (“MLPs”)  
Money Market Instruments
Mortgage-Backed Securities (“MBS”)
Mortgage Dollar Rolls
Municipal Lease Obligations (“MLOs”)  
Municipal Obligations
Option Contracts
Participation Notes  
Pooled Investment Vehicles
Preferred Stock  
Real Estate Investments
Repurchase Agreements
Residual Interest Bonds  
Reverse Repurchase Agreements

Calvert Mortgage Access Fund 3 SAI dated [______], 2022

 

 

Investment Type Permitted for or Relevant to the Fund
Rights and Warrants  
Senior Loans
Short Sales
Special Equities Investments  
Stripped Securities
Structured Notes
Swap Agreements
Swaptions
Trust Certificates
U.S. Government Securities
Unlisted Securities  
Variable Rate Instruments
Venture Capital Limited Partnerships  
When-Issued Securities, Delayed Delivery and Forward Commitments
Zero Coupon Bonds, Deep Discount Bonds and Payment In-Kind (“PIK”) Securities

 

Other Disclosures Regarding Investment Practices Permitted for or Relevant to the Fund
Asset Coverage
Average Effective Maturity  
Borrowing for Investment Purposes
Borrowing for Temporary Purposes
Credit Spread Trades  
Cybersecurity Risk
Diversified Status  
Duration
Index Tracking  
LIBOR Transition and Associated Risk
Operational Risk
Participation in the ReFlow Liquidity Program
Portfolio Turnover
Restricted Securities
Securities Lending
Short-Term Trading
Significant Exposure to the Banking Industry  
Significant Exposure to Global Energy Solutions Companies  
Significant Exposure to Smaller Companies  
Significant Exposure to Technology Companies  
Significant Exposure to Water Companies  

 

Calvert Mortgage Access Fund 4 SAI dated [______], 2022

 

INVESTMENT RESTRICTIONS

The following investment restrictions of the Fund are designated as
fundamental policies and as such cannot be changed without the approval of the holders of a majority of the Fund’s outstanding voting
securities, which as used in this SAI means the lesser of: (a) 67% of the shares of the Fund present or represented by proxy at a meeting
if the holders of more than 50% of the outstanding shares are present or represented at the meeting; or (b) more than 50% of the outstanding
shares of the Fund. Accordingly, the Fund may not:

(1) Borrow money or issue senior securities except as permitted by the 1940 Act;
(2) Purchase securities on margin (but the Fund may obtain such short-term credits as may be necessary for the clearance of purchases
and sales of securities). The deposit or payment by the Fund of initial, maintenance or variation margin in connection with all types
of options and futures contract transactions is not considered the purchase of a security on margin;
(3) Underwrite or participate in the marketing of securities of others, except insofar as it may technically be deemed to be an underwriter
in selling a portfolio security under circumstances which may require the registration of the same under the Securities Act of 1933;
(4) Purchase or sell real estate, although it may purchase and sell securities which are secured by real estate and securities of companies
which invest or deal in real estate;
(5) Make loans to other persons except by (a) the acquisition of debt instruments and making portfolio investments, (b) entering into
repurchase agreements, (c) lending portfolio securities and (d) lending cash consistent with applicable law;

In addition, the Fund may not:

(6) Concentrate its investments in the securities of any one industry, except the real estate industry and except securities issued or guaranteed
by the U.S. Government or any of its agencies or instrumentalities, if as a result 25% or more of the Fund’s total assets would
be invested in securities of such industry.

In addition, the Fund may:

(7) Purchase and sell commodities and commodities contracts of all types and kinds (including without limitation futures contracts, options
on futures contracts and other commodities-related investments) to the extent permitted by law.

For purposes of determining industry classifications, the investment
adviser considers an issuer to be in a particular industry if a third party has designated the issuer to be in that industry, unless the
investment adviser is aware of circumstances that make the third party’s classification inappropriate. In such a case, the investment
adviser will assign an industry classification to the issuer.

The following nonfundamental investment policy has been adopted by the
Fund. A nonfundamental investment policy may be changed by the Board with respect to the Fund without approval by the Fund’s shareholders.
The Fund will not make short sales of securities or maintain a short position, unless at all times when a short position is open (i) it
owns an equal amount of such securities or securities convertible into or exchangeable, without payment of any further consideration,
for securities of the same issue as, and equal in amount to, the securities sold short or (ii) it holds in a segregated account cash or
other liquid securities (to the extent required under the 1940 Act) in an amount equal to the current market value of the securities sold
short, and unless not more than 25% of its net assets (taken at current value) is held as collateral for such sales at any one time.

Notwithstanding its investment policies and restrictions, the Fund may,
in compliance with the requirements of the 1940 Act, invest: (i) all of its investable assets in an open-end management investment company
with substantially the same investment objective(s), policies and restrictions as the Fund; or (ii) in more than one open-end management
investment company sponsored by CRM or its affiliates, provided any such company has investment objective(s), policies and restrictions
that are consistent with those of the Fund.

In addition, to the extent a registered open-end investment company
acquires securities of a fund in reliance on Section 12(d)(1)(G) under the 1940 Act, such acquired fund shall not acquire any securities
of a registered open-end investment company in reliance on Sections 12(d)(1)(F) or 12(d)(1)(G) under the 1940 Act.

The Fund’s borrowing policy is consistent with the 1940 Act and
guidance of the SEC or its staff, and will comply with any applicable SEC exemptive order.

Whenever an investment policy or investment restriction set forth in
the Prospectus or this SAI states a requirement with respect to the percentage of assets that may be invested in any security or other
asset, or describes a policy regarding quality standards, such percentage limitation or standard shall be determined immediately after
and as a result of the acquisition by the Fund of such security or asset. Accordingly, unless otherwise noted, any later increase or decrease

Calvert Mortgage Access Fund 5 SAI dated [______], 2022

resulting from a change in values, assets or other circumstances or
any subsequent rating change made by a rating service (or as determined by the investment adviser if the security is not rated by a rating
agency), will not compel the Fund to dispose of such security or other asset. However, the Fund must always be in compliance with the
borrowing policy set forth above. If the Fund is required to reduce borrowings, it will do so in a manner that is consistent with the
1940 Act and guidance of the SEC or its staff, and that complies with any applicable SEC exemptive order.

MANAGEMENT AND ORGANIZATION

Fund Management.
The Trustees of the Trust are responsible for the overall management and supervision of the affairs of the Trust. The Board members and
officers of the Trust are listed below. Except as indicated, each individual has held the office shown or other offices in the same company
for the last five years. Board members hold indefinite terms of office. Each Board member holds office until his or her successor is elected
and qualified, or until his or her earlier death, resignation, retirement, removal or disqualification. Under the terms of the Fund’s
current Board member retirement policy, an Independent Board member must retire at the end of the calendar year in which he or she turns
75. However, if such retirement would cause the Fund to be out of compliance with Section 16 of the 1940 Act or any other regulations
or guidance of the SEC, then such retirement will not become effective until such time as action has been taken for the Fund to be in
compliance therewith. The “noninterested Trustees” consist of those Trustees who are not “interested persons”
of the Trust, as that term is defined under the 1940 Act. The business address of each Board member and the Chief Compliance Officer is
1825 Connecticut Avenue, NW, Suite 400, Washington, DC 20009 and the business address of the Secretary, Vice President and Chief Legal
Officer and the Treasurer is Two International Place, Boston, Massachusetts 02110. As used in this SAI, “CRM” refers to Calvert
Research and Management, “Eaton Vance” refers to Eaton Vance Management, “EVC” refers to Eaton Vance Corp., “EV”
refers to EV LLC, and “EVD” refers to Eaton Vance Distributors, Inc. (see “Principal Underwriter” under “Other
Service Providers”). EV is the trustee of each of Eaton Vance and CRM. Effective March 1, 2021, each of Eaton Vance, CRM, EVD and
EV are indirect wholly owned subsidiaries of Morgan Stanley. Each officer affiliated with CRM may hold a position with other CRM affiliates
that is comparable to his or her position with CRM listed below.

Name and Year of Birth   Trust Position(s)   Length of Service   Principal Occupation(s) During Past Five Years
and Other Relevant Experience
  Number of Calvert Funds
in Fund Complex
Overseen By
Trustee
  Other Directorships Held
During Last Five Years
Interested Trustee                    
JOHN H. STREUR
1960
  Trustee and President   Since 2015   President and Chief Executive Officer of Calvert Research and Management (since December 31, 2016); President and Chief Executive Officer of Calvert Investments, Inc. (January 2015-December 2016); Chief Executive Officer of Calvert Investments Distributors, Inc. (August 2015-December 2016); Chief Compliance Officer of Calvert Investment Management, Inc. (August 2015-April 2016); President and Director, Portfolio 21 Investments, Inc. (through October 2014); President, Chief Executive Officer and Director, Managers Investment Group LLC (through January 2012); President and Director, The Managers Funds and Managers AMG Funds (through January 2012).  Mr. Streur is an interested person because of his positions with CRM and certain affiliates.   39  

Portfolio 21 Investments, Inc. (asset management)
(through October 2014)

Managers Investment Group LLC (asset management)
(through January 2012)

The Managers Funds (asset management) (through
January 2012)

Managers AMG Funds (asset management) (through
January 2012)

Calvert Impact Capital, Inc.

Calvert Mortgage Access Fund 6 SAI dated [______], 2022

 

 

Name and Year of Birth   Trust Position(s)   Length of Service   Principal Occupation(s) During Past Five Years
and Other Relevant Experience
  Number of Calvert Funds
in Fund Complex
Overseen By
Trustee
  Other Directorships Held
During Last Five Years
Noninterested Trustees                    
RICHARD L. BAIRD, JR.
1948
  Trustee   Since 1982   Regional Disaster Recovery Lead, American Red Cross of Greater Pennsylvania (since 2017).  Volunteer, American Red Cross (since 2015).  Former President and CEO of Adagio Health Inc. (retired in 2014) in Pittsburgh, PA.   39   None
ALICE GRESHAM BULLOCK
1950
  Chair and Trustee   Since 2016   Professor Emerita at Howard University School of Law. Dean Emerita of Howard University School of Law and Deputy Director of the Association of American Law Schools (1992-1994).   39   None
CARI M. DOMINGUEZ
1949
  Trustee   Since 2016   Former Chair of the U.S. Equal Employment Opportunity Commission.   39  

ManpowerGroup Inc. (workforce solutions
company)

Triple S Management Corporation (managed care)

National Association of Corporate Directors

JOHN G. GUFFEY, JR.
1948
  Trustee   Since 1982   President of Aurora Press Inc., a privately held publisher of trade paperbacks (since January 1997).   39   Calvert Impact Capital, Inc. (through December 31, 2018)
MILES D. HARPER, III
1962
  Trustee   Since 2016   Partner, Carr Riggs & Ingram (public accounting firm) since October 2014. Partner, Gainer Donnelly & Desroches (public accounting firm) (now Carr Riggs & Ingram), (November 1999-September 2014).   39   Bridgeway Funds (9) (asset management)

Calvert Mortgage Access Fund 7 SAI dated [______], 2022

 

Name and Year of Birth   Trust Position(s)   Length of Service   Principal Occupation(s) During Past Five Years
and Other Relevant Experience
  Number of Calvert Funds
in Fund Complex
Overseen By
Trustee
  Other Directorships Held
During Last Five Years
JOY V. JONES
1950
  Trustee   Since 2016   Attorney.   39   Palm Management Corporation
ANTHONY A. WILLIAMS
1951
  Trustee   Since 2010   CEO and Executive Director of the Federal City Council (July 2012 to present);
Senior Adviser and Independent Consultant for King and Spalding LLP (September 2015 to present); Executive Director of Global Government
Practice at the Corporate Executive Board (January 2010 to January 2012).
  39  

Freddie Mac

Evoq Properties/Meruelo Maddux Properties,
Inc. (real estate management)

Weston Solutions, Inc. (environmental services)

Bipartisan Policy Centers Debt Reduction
Task Force

Chesapeake Bay Foundation

Catholic University of America

Urban Institute (research organization)

The Howard Hughes Corporation (real estate development)

  

Principal Officers who are not Trustees
Name and Year of Birth   Trust Position(s)   Length of Service   Principal Occupation(s) During Past Five Years
DEIDRE E. WALSH
1971
  Secretary, Vice President and Chief Legal Officer   Since 2021   Vice President of CRM and officer of 39 registered investment companies advised by CRM.  Also Vice President of Eaton Vance and certain of its affiliates and officer of 138 registered investment companies advised or administered by Eaton Vance.
JAMES F. KIRCHNER
1967
  Treasurer   Since 2016   Vice President of CRM and officer of 39 registered investment companies advised by CRM (since 2016).  Also Vice President of Eaton Vance and certain of its affiliates and officer of 138 registered investment companies advised or administered by Eaton Vance.
HOPE L. BROWN
1973
  Chief Compliance Officer   Since 2014   Chief Compliance Officer of 39 registered investment companies advised by CRM (since 2014). Vice President and Chief Compliance Officer, Wilmington Funds (2012-2014).

The Board has general oversight responsibility with respect to the business
and affairs of the Trust and the Fund. The Board has engaged an investment adviser and (if applicable) a sub-adviser (collectively the
“adviser”) to manage the Fund and an administrator to administer the Fund and is responsible for overseeing such
adviser and administrator and other service providers to the Trust and the Fund. The Board is currently composed of eight Trustees, including
seven Trustees who are not “interested persons” of the Fund, as that term is defined in the 1940 Act (each a “noninterested
Trustee”). In addition to four regularly scheduled meetings per year, the Board holds special meetings or informal conference calls
to discuss specific matters that may require action prior to the next regular meeting. As discussed below, the Board has established two
committees to assist the Board in performing its oversight responsibilities.

Calvert Mortgage Access Fund 8 SAI dated [______], 2022

The Board has appointed a noninterested Trustee to serve in the role
of Chairperson. The Chairperson’s primary role is to participate in the preparation of the agenda for meetings of the Board and
the identification of information to be presented to the Board with respect to matters to be acted upon by the Board. The Chairperson
also presides at all meetings of the Board and acts as a liaison with service providers, officers, attorneys, and other Board members
generally between meetings. The Chairperson may perform such other functions as may be requested by the Board from time to time. Ms. Gresham
Bullock serves as Chair of the Board as an “independent” Board member. Except for any duties specified herein or pursuant
to the Trust’s Declaration of Trust or By-laws, the designation of Chairperson does not impose on such noninterested Trustee any
duties, obligations or liability that is greater than the duties, obligations or liability imposed on such person as a member of the Board,
generally.

The Board believes that each Trustee’s experience, qualifications,
attributes or skills on an individual basis and in combination with those of the other Trustees lead to the conclusion that the Trustees
possess the requisite experience, qualifications, attributes and skills to serve on the Board. The Board believes that the Trustees’
ability to review critically, evaluation, question and discuss information provided to them with the Adviser, sub-advisers, if applicable,
other service providers, legal counsel and independent public accountants; and to exercise effective business judgment in the performance
of their duties as Trustees, support this conclusion. The Board has also considered the contributions that each Trustee can make to the
Board and the Fund. In addition, the following specific experience, qualifications, attributes and/or skills apply as to each Trustee:
Mr. Baird, experiences as a chief executive officer of a non-profit corporation; Ms. Gresham Bullock, academic leadership experience,
legal experience and experience as a board member of various organizations; Ms. Dominguez, experience as Chair of the U.S. Equal Employment
Opportunity Commission and experience as a board member of various organizations; Mr. Guffey, experience as a director and officer of
private companies and experience as a board member of various organizations; Mr. Harper, experience as a partner of a public accounting
firm and experience as a board member of a mutual fund complex; Ms. Jones, legal experience and experience as a director of a private
foundation; Mr. Williams, experience as the mayor of the District of Columbia and as a board member of various organizations; and Mr.
Streur, leadership roles within the Adviser and experience building and managing investment management firms.

The Fund’s Audit Committee approves and recommends to the Board
the approval of independent public accountants to conduct the annual audit of the Fund’s financial statements; reviews with the
independent public accountants the outline, scope, and results of the Fund’s annual audit; and reviews the performance of, and fees
charged by, the independent public accountants for professional services.  In addition, the Audit Committee meets with the Fund’s
independent public accountants and representatives of Fund management, as applicable, to review accounting activities and areas of financial
reporting and control. The following individuals are members of the Board’s Audit Committee: Messrs. Baird, Guffey, Harper, and
Williams, and Mses. Gresham Bullock, Dominguez, and Jones. Mr. Harper serves as the Audit Committee Financial Expert.

The Governance Committee of the Fund addresses matters of fund governance,
including policies on Trustee compensation and on Board and committee structure and responsibilities. The functions of the Governance
Committee of each Board also include those of a Nominating Committee — e.g., the initiation and consideration of nominations for the
appointment or election of independent Trustees of the Boards, as applicable. When identifying and evaluating prospective nominees for
vacancies on the Board, the Committee reviews all recommendations in the same manner, including those received from shareholders. See
also “Process for Delivering Shareholder Communications to the Board of Trustees” for additional restrictions. The Committee
determines if the prospective nominee meets the specific qualifications set forth in the Committee’s charter, and any other qualifications
deemed to be important by the Committee.

The Board believes that diversity is an important attribute of a
well-functioning board. The current Board is comprised of four white males, one African American male, two African American females
and one Hispanic female. The Governance Committee is responsible for advising the Board upon request on matters of diversity,
including race, gender, culture, thought, and geography; and for recommending, as necessary, measures contributing to a Board that,
as a whole, reflects a range of viewpoints, backgrounds, skills, experience, and expertise. In the process of searching for
qualified persons to serve on the Board, the Committee strives for the inclusion of diverse groups, knowledge, and viewpoints. To
accomplish this, the Committee may retain an executive search firm to help meet the Committee’s diversity objective as well as
form alliances with organizations representing the interests of women and minorities. In connection with its efforts to create and
maintain a diverse Board, the Committee may develop recruitment protocols that seek to include diverse candidates in any
director/trustee search. These protocols should: (i) take into account that qualified, but often overlooked, candidates may be found
in a broad array of organizations, including academic institutions, privately held businesses, nonprofit organizations, and trade
associations, in addition to the traditionally recognized candidate pool of public company directors and officers; (ii) strive to
use the current network of organizations and trade groups that may help identify diverse candidates; and (iii) periodically review
director/trustee recruitment and selection protocols so that diversity remains a component of any director/trustee search. The
Committee shall, as it deems appropriate, periodically review Board composition to ensure that the Board reflects a balance of
knowledge, experience, skills, expertise, and diversity, including racial and gender diversity, required for the Board to fulfill
its duties. The following individuals serve as members of the Board’s Governance Committee: Messrs. Baird, Guffey, Harper, and
Williams, and Mses. Gresham Bullock, Dominguez, and Jones.

Calvert Mortgage Access Fund 9 SAI dated [______], 2022

An integral part of the Board’s overall responsibility for overseeing
the management and operations of the Fund is the Board’s oversight of the risk management of the Fund’s investment programs
and business affairs.  The Fund is subject to a number of risks, such as investment risk, credit and counterparty risk, valuation
risk, risk of operational failure or lack of business continuity, and legal, compliance and regulatory risk.  The Fund, the Adviser,
and other service providers to the Fund have implemented various processes, procedures and controls intended to identify and address risks
to the Fund.  Different processes, procedures and controls are employed with respect to different types of risks.

The Board exercises oversight of the risk management process primarily
through the Audit Committee and through oversight by the Board itself.  In addition to adopting, and periodically reviewing, policies
and procedures designed to address risks to the Fund, the Board requires management of the Adviser and the Fund, including the Fund’s
Chief Compliance Officer (“CCO”), to report to the Board and the Committees of the Board on a variety of matters, including
matters relating to risk management, at regular and special meetings. The Board and the Audit Committee receive regular reports from the
Fund’s independent public accountants on internal control and financial reporting matters.  On at least a quarterly basis,
the Independent Trustees meet with the Fund’s CCO, including outside the presence of management, to discuss issues related to compliance. 
Furthermore, the Board receives a quarterly report from the Fund’s CCO regarding the operation of the compliance policies and procedures
of the Fund and its primary service providers.  The Board also receives regular reports from the Adviser on the investments and securities
trading of the Fund, including its investment performance and asset weightings compared to appropriate benchmarks, as well as reports
regarding the valuation of the Fund’s securities.  The Board also receives reports from the Fund’s primary service providers
regarding their operations as they relate to the Fund.

Share Ownership.
The following table shows the dollar range of equity securities beneficially owned by each Trustee in the Fund and in the Calvert family
of funds overseen by the Trustee as of December 31, 2021. None of the Trustees owned shares of the Fund as of December 31, 2021 since
the Fund had not yet commenced operations.

Name of Trustee Aggregate Dollar Range of Equity
Securities Beneficially Owned in All
Registered Funds Overseen by
Trustee in the Calvert Family of Funds
Interested Trustee  
John H. Streur Over $100,000
Noninterested Trustees  
Richard L. Baird, Jr. Over $100,000(1)
Alice Gresham Bullock Over $100,000(1)
Cari M. Dominguez Over $100,000
John G. Guffey, Jr. Over $100,000
Miles D. Harper, III Over $100,000(1)
Joy V. Jones Over $100,000(1)
Anthony A. Williams $10,001 – $50,000(1)
(1) Includes shares
which may be deemed to be beneficially owned through the Trustee Deferred Compensation Plan.

As of December 31, 2021, no noninterested Trustee or any of their immediate
family members owned beneficially or of record any class of securities of Morgan Stanley, EVD, any sub-adviser, if applicable, or any
person controlling, controlled by or under common control with Morgan Stanley or EVD or any sub-adviser, if applicable, collectively (“Affiliated
Entity”).

During the calendar years ended December 31, 2020 and December 31, 2021,
no noninterested Trustee (or their immediate family members) had:

(1) Any direct or indirect interest in any Affiliated Entity;
(2) Any direct or indirect material interest in any transaction or series of similar transactions with (i) the Trust or any fund; (ii)
another fund managed or distributed by any Affiliated Entity; (iii) any Affiliated Entity; or (iv) an officer of any of the above; or
(3) Any direct or indirect relationship with (i) the Trust or any fund; (ii) another fund managed or distributed by any Affiliated Entity;
(iii) any Affiliated Entity; or (iv) an officer of any of the above.

Calvert Mortgage Access Fund 10 SAI dated [______], 2022

During the calendar years ended December 31, 2020 and December 31, 2021,
no officer of any Affiliated Entity served on the Board of Directors of a company where a noninterested Trustee of the Trust or any of
their immediate family members served as an officer.

Noninterested Trustees may elect to defer receipt of all or a percentage
of their annual fees in accordance with the terms of a Trustees Deferred Compensation Agreement (the “Deferred Compensation Agreement”).
Under the Deferred Compensation Agreement, an eligible Board member may elect to have all or a portion of his or her deferred fees invested
in the shares of one or more funds in the Calvert family of funds, and the amount paid to the Board members under the Deferred Compensation
Agreement will be determined based upon the performance of such investments. Deferral of Board members’ fees in accordance with
the Deferred Compensation Agreement will have a negligible effect on the assets, liabilities, and net income of a participating fund or
portfolio, and do not require that a participating Board member be retained. There is no retirement plan for Board members.

The fees and expenses of the Trustees of the Trust are paid by the Fund
(and other series of the Trust). A Board member who is a member of the Calvert organization receives no compensation from the Trust. During
the fiscal year ended [ ], it is estimated that the Trustees of the Trust will earn the following compensation in their capacities as
Board members from the Trust. For the year ended December 31, 2021, the Board members earned the following compensation in their capacities
as members of the Calvert Fund Boards(1):

Source of Compensation Richard L.
Baird, Jr.
Alice Gresham
Bullock
Cari M.
Dominguez
John G.
Guffey, Jr.
Miles D.
Harper, III
Joy V.
Jones
Anthony A.
Williams
Trust(2) $[   ] $[   ] $[   ] $[   ] $[   ] $[   ] $[   ]
Trust and Fund Complex(1) $186,500(6) $216,500(7) $186,500 $189,000(8) $192,500 $192,500 $186,500
(1) As of [ ], 2022, the Calvert fund complex consists of [ ] registered investment companies.
(2) The Trust consisted of [ ] Funds as of [ ].
(3) Includes $[  ] of deferred compensation.
(4) Includes $[  ] of deferred compensation.
(5) Includes $[  ] of deferred compensation.
(6) Includes $65,275 of deferred compensation.
(7) Includes $21,650 of deferred compensation.
(8) Includes $113,400 of deferred compensation.

Fund Organization

Trust. The
Fund is a series of the Trust, which was organized under Massachusetts law on October 27, 1980 as a trust with transferable shares, commonly
referred to as a “Massachusetts business trust” and is operated as an open-end management investment company. The Trust may
issue an unlimited number of shares of beneficial interest (no par value per share) in one or more series (such as the Fund). The Trustees
of the Trust have divided the shares of the Fund into multiple classes. Each class represents an interest in the Fund, but is subject
to different expenses, rights and privileges. The Trustees have the authority under the Declaration of Trust to create additional classes
of shares with differing rights and privileges. When issued and outstanding, shares are fully paid and nonassessable by the Trust. Shareholders
of the Trust are entitled to one vote for each full share held. Fractional shares may be voted proportionately. Shares of all Funds in
the Trust will be voted together with respect to the election or removal of Trustees and on other matters affecting all Funds similarly.
On matters affecting only a particular Fund, all shareholders of the affected Fund will vote together as a single class, except that only
shareholders of a particular class may vote on matters affecting only that class. Shares have no preemptive or conversion rights and are
freely transferable. In the event of the liquidation of the Fund, shareholders of each class are entitled to share pro rata in the net
assets attributable to that class available for distribution to shareholders.

As permitted by Massachusetts law, there will normally be no meetings
of shareholders for the purpose of electing Trustees unless and until such time as less than a majority of the Trustees of the Trust holding
office have been elected by shareholders. In such an event the Trustees then in office will call a shareholders’ meeting for the
election of Trustees. Except for the foregoing circumstances and unless removed by action of the shareholders in accordance with the Trust’s
By-laws, the Trustees shall continue to hold office and may appoint successor Trustees. The Trust’s By-laws provide that any Trustee
may be removed with or without cause, by (i) the affirmative vote of holders of two-thirds of the shares or, (ii) the affirmative vote
of two-thirds of the remaining Trustees.

The Trust’s Declaration of Trust may be amended by the Trustees
when authorized by vote of a majority of the outstanding voting securities of the Trust, the financial interests of which are affected
by the amendment. The Trustees may also amend the Declaration of Trust without the vote or consent of shareholders to change the name
of the Trust or any series, if they deem it necessary to conform it to applicable federal or state laws or regulations, or to make such
other

Calvert Mortgage Access Fund 11 SAI dated [______], 2022

changes (such as reclassifying series or classes of shares or restructuring
the Trust) provided such changes do not have a materially adverse effect on the financial interests of shareholders. The Trust’s
Declaration of Trust provides that the Trust will indemnify its Trustees and officers against liabilities and expenses incurred in connection
with any litigation or proceeding in which they may be involved because of their offices with the Trust. However, no indemnification is
required to be provided to any Trustee or officer for any liability to the Trust or shareholders by reason of willful misfeasance, bad
faith, gross negligence or reckless disregard of the duties involved in the conduct of his or her office.

The Trust’s Declaration of Trust provides that any legal proceeding
brought by or on behalf of a shareholder seeking to enforce any provision of, or based upon any matter arising out of, related to or in
connection with, the Declaration of Trust, the Trust, any Fund or Class or the shares of any Fund must be brought exclusively in the United
States District Court for Massachusetts or, if such court does not have jurisdiction for the matter, then in the Superior Court of Suffolk
County for the Commonwealth of Massachusetts. If a shareholder brings a claim in another venue and the venue is subsequently changed through
legal process to the foregoing Federal or state court, then the shareholder will be required to reimburse the Trust and other persons
for the expenses incurred in effecting the change in venue.

The Trust’s Declaration of Trust also provides that, except to
the extent explicitly permitted by Federal law, a shareholder may not bring or maintain a court action on behalf of the Trust or any Fund
or class of shares (commonly referred to as a derivative claim) without first making demand on the Trustees requesting the Trustees to
bring the action. Within 90 days of receipt of the demand, the Trustees will consider the merits of the claim and determine whether commencing
or maintaining an action would be in the best interests of the Trust or the affected Fund or Class. Any decision by the Trustees to bring,
maintain or settle, or to not bring, maintain or settle the action, will be final and binding upon shareholders and therefore no action
may be brought or maintained after a decision is made to reject a demand. In addition, the Trust’s Declaration of Trust provides
that, to the maximum extent permitted by law, each shareholder acknowledges and agrees that any alleged injury to the Trust’s property,
any diminution in the value of a shareholder’s shares and any other claim arising out of or relating to an allegation regarding
the actions, inaction or omissions of or by the Trustees, the officers of the Trust or the investment adviser of the Fund is a legal claim
belonging only to the Trust and not to the shareholders individually and, therefore, that any such claim is subject to the demand requirement
for derivative claims referenced above.

Under Massachusetts law, if certain conditions prevail, shareholders
of a Massachusetts business trust (such as the Trust) could be deemed to have personal liability for the obligations of the Trust. Numerous
investment companies registered under the 1940 Act have been formed as Massachusetts business trusts, and management is not aware of an
instance where such liability has been imposed. The Trust’s Declaration of Trust contains an express disclaimer of liability on
the part of Fund shareholders and the Trust’s Declaration of Trust provides that the Trust, upon request by the shareholder, shall
assume the defense on behalf of any Fund shareholders. The Declaration of Trust also contains provisions limiting the liability of a series
or class to that series or class. Moreover, the Trust’s Declaration of Trust also provides for indemnification out of Fund property
of any shareholder held personally liable solely by reason of being or having been a shareholder for all loss or expense arising from
such liability. The assets of the Fund are readily marketable and will ordinarily substantially exceed its liabilities. In light of the
nature of the Fund’s business and the nature of its assets, management believes that the possibility of the Fund’s liabilities
exceeding its assets, and therefore the shareholder’s risk of personal liability, is remote.

Proxy Voting
Policy.
The Board adopted a proxy voting policy and procedures (the “Fund Policy”), pursuant to which the Board
has delegated proxy voting responsibility to the investment adviser and adopted the proxy voting policies and procedures of the investment
adviser (the “Adviser Policies”). An independent proxy voting service has been retained to assist in the voting of Fund proxies
through the provision of vote analysis, implementation and recordkeeping and disclosure services. The members of the Board will review
a Fund’s proxy voting records from time to time and will review annually the Adviser Policies. For a copy of the Fund Policy and Adviser
Policies, see Appendix F and Appendix G, respectively. Pursuant to certain provisions of the 1940 Act and certain exemptive orders relating
to funds investing in other funds, a Fund may be required or may elect to vote its interest in another fund in the same proportion as
the holders of all other shares of that fund. Information on how a Fund voted proxies relating to portfolio securities during the most
recent 12-month period ended June 30 is available (1) without charge, upon request, by calling 1-800-368-2745, (2) on the SEC’s
website at http://www.sec.gov and (3) on the Funds’ website at https://www.calvert.com/Proxy-Voting.php.

Process for
Delivering Shareholder Communications to the Board of Trustees.
Any shareholder who wishes to send a communication to the Board
of Trustees of the Fund should send the communication to the attention of the Fund’s Secretary at the following address:

Calvert Funds
Attn: [Name of Fund] Secretary
Two International Place
Boston, MA 02110

Calvert Mortgage Access Fund 12 SAI dated [______], 2022

All communications should state the specific Calvert fund to which the
communication relates. After reviewing the communication, the Fund’s Secretary will forward the communication to the Board of Trustees.

In its function as a nominating committee, the Governance Committee
of the Board of Trustees will consider any candidates for vacancies on the Board from any shareholder of the Fund who, for at least five
years, has continuously owned at least 0.5% of the outstanding shares of the Fund. Shareholders of the Fund who wish to nominate a candidate
to the Board must submit the recommendation in writing to the attention of the Fund’s Secretary at Two International Place, Boston,
MA 02110. The recommendation must include biographical information, including business experience for the past ten years and a description
of the qualifications of the proposed nominee, along with a statement from the proposed nominee that he or she is willing to serve and
meets the requirements to be an independent Trustee. A shareholder wishing to recommend to the Governance Committee of the Fund a candidate
for election as a Trustee may request the Fund’s Policy for the Consideration of Trustee Nominees by contacting the Fund’s
Secretary at the address above.

If a shareholder wishes to send a communication directly to an individual
Trustee or to a Committee of the Fund’s Board of Trustees, then the communication should be specifically addressed to such individual
Trustee or Committee and sent in care of the Fund’s Secretary at the address above. Communications to individual Trustees or to
a Committee sent in care of the Fund’s Secretary will be forwarded to the individual Trustee or to the Committee, as applicable.

INVESTMENT ADVISORY AND ADMINISTRATIVE SERVICES

Investment
Advisory Services.
  The investment adviser manages the investments and affairs of the Fund and provides related office
facilities and personnel subject to the supervision of the Trust’s Board. The investment adviser furnishes investment research,
advice and supervision, furnishes an investment program and determines what securities will be purchased, held or sold by the Fund
and what portion, if any, of the Fund’s assets will be held uninvested. The Investment Advisory Agreement requires the
investment adviser to pay the compensation and expenses of all officers and Trustees who are members of the investment adviser’s organization
and all personnel of the investment adviser performing services relating to research and investment activities.

The Investment Advisory Agreement with the investment adviser continues
in effect through and including the second anniversary of its execution and shall continue in full force and effect indefinitely thereafter,
but only so long as such continuance after such second anniversary is specifically approved at least annually (i) by the vote of a majority
of the noninterested Trustees of the Trust cast at a meeting specifically called for the purpose of voting on such approval pursuant to
the requirements of the 1940 Act and (ii) by the Board of the Trust or by vote of a majority of the outstanding voting securities of the
Fund. The Agreement may be terminated at any time without penalty on sixty (60) days’ written notice by either party, or by vote
of the majority of the outstanding voting securities of the Fund, and the Agreement will terminate automatically in the event of its assignment. The
Agreement provides that the investment adviser may render services to others. The Agreement also provides that the investment adviser
shall not be liable for any loss incurred in connection with the performance of its duties, or action taken or omitted under the Agreement,
in the absence of willful misfeasance, bad faith, gross negligence or reckless disregard of its obligations and duties thereunder, or
for any losses sustained in the acquisition, holding or disposition of any security or other investment. The Agreement is not intended
to, and does not, confer upon any person not a party to it any right, benefit or remedy of any nature.

Information
About CRM and Eaton Vance.
 CRM is a subsidiary of Eaton Vance. CRM and Eaton Vance are business trusts organized under
the laws of the Commonwealth of Massachusetts. EV serves as trustee of CRM and Eaton Vance. As described in the Prospectus, following
the closing of the Transaction on March 1, 2021, EV, Eaton Vance and CRM became indirect wholly owned subsidiaries of Morgan Stanley (NYSE:
MS), a preeminent global financial services firm engaged in securities trading and brokerage activities, as well as providing investment
banking, research and analysis, financing and financial advisory services.

Prior to March 1, 2021, each of EV and Eaton Vance were wholly
owned subsidiaries of EVC, a Maryland corporation and publicly-held holding company, and CRM was an indirect wholly owned subsidiary
of EVC. EVC through its subsidiaries and affiliates engaged primarily in investment management, administration and marketing
activities. The Directors of EVC were Thomas E. Faust Jr., Ann E. Berman, Leo I. Higdon, Jr., Paula A. Johnson, Brian D. Langstraat,
Dorothy E. Puhy, Winthrop H. Smith, Jr. and Richard A. Spillane, Jr. All shares of the outstanding Voting Common Stock of EVC were
deposited in a Voting Trust, the Voting Trustees of which were Mr. Faust, Paul W. Bouchey, Craig R. Brandon, Daniel C. Cataldo,
Michael A. Cirami, Cynthia J. Clemson, James H. Evans, Maureen A. Gemma, Laurie G. Hylton, Mr. Langstraat, Thomas Lee, Frederick S.
Marius, David C. McCabe, Edward J. Perkin, Lewis R. Piantedosi, Charles B. Reed, Craig P. Russ, Thomas C. Seto, John L. Shea, Eric
A. Stein, John H. Streur, Andrew N. Sveen, Payson F. Swaffield, R. Kelly Williams and Matthew J. Witkos (all of whom are or were
officers of Eaton Vance or its affiliates). The Voting Trustees had unrestricted voting rights for the election of Directors of EVC.
Prior to March 1, 2021, all of the outstanding voting trust receipts issued under said Voting Trust were owned by certain of the
officers of CRM and Eaton Vance who may also have been officers, or officers and Directors of EVC and EV. As indicated under
“Management and Organization,” all of the officers of the Trust (as well as Mr. Streur who is also a Trustee) are
employees of CRM.

Calvert Mortgage Access Fund 13 SAI dated [______], 2022

Code of Ethics.
The investment adviser, principal underwriter, and the Fund have adopted Codes of Ethics governing personal securities transactions
pursuant to Rule 17j-1 under the 1940 Act. Under the Codes, employees of the investment adviser and the principal underwriter may purchase
and sell securities (including securities held or eligible for purchase by the Fund) subject to the provisions of the Codes and certain
employees are also subject to pre-clearance, reporting requirements and/or other procedures.

Portfolio
Managers.
The portfolio managers (each referred to as a “portfolio manager”) of the Fund are listed below. The
following table shows, as of [ ], the number of accounts each portfolio manager managed in each of the listed categories and the total
assets (in millions of dollars) in the accounts managed within each category. The table also shows the number of accounts with respect
to which the advisory fee is based on the performance of the account, if any, and the total assets (in millions of dollars) in those accounts.

  Number of
All Accounts
Total Assets of
All Accounts
Number of Accounts
Paying a Performance Fee
Total Assets of Accounts
Paying a Performance Fee
 Andrew Szczurowski(1)        
Registered Investment Companies [  ] $[  ] [  ] $[  ]
Other Pooled Investment Vehicles [  ] $[  ] [  ] $[  ]
Other Accounts [  ] $[  ] [  ] $[  ]
 Alexander Payne        
Registered Investment Companies [  ] $[  ] [  ] $[  ]
Other Pooled Investment Vehicles [  ] $[  ] [  ] $[  ]
Other Accounts [  ] $[  ] [  ] $[  ]
(1) This portfolio manager serves as portfolio manager of one or more registered investment companies and/or pooled investment vehicles
that invest or may invest in one or more underlying registered investment companies and/or separate pooled investment vehicles in the
Eaton Vance family of funds. The underlying investment companies may be managed by this portfolio manager or another portfolio manager.

The portfolio managers did not beneficially own any equity securities
of the Fund since the Fund had not yet commenced operations prior to the date of this SAI. The following table shows the dollar range
of equity securities beneficially owned in the Calvert family of funds as of December 31, 2021.

Portfolio Managers Aggregate Dollar Range of Equity
Securities Beneficially Owned in the
Calvert Family of Funds
Andrew Szczurowski [$     ]
Alexander Payne [$     ]

It is possible that conflicts of interest may arise in connection with
a portfolio manager’s management of the Fund’s investments on the one hand and the investments of other accounts for which
a portfolio manager is responsible on the other. For example, a portfolio manager may have conflicts of interest in allocating management
time, resources and investment opportunities among the Fund and other accounts he advises. In addition, due to differences in the investment
strategies or restrictions between the Fund and the other accounts, the portfolio manager may take action with respect to another account
that differs from the action taken with respect to the Fund. In some cases, another account managed by a portfolio manager may compensate
the investment adviser based on the performance of the securities held by that account. The existence of such a performance based fee
may create additional conflicts of interest for the portfolio manager in the allocation of management time, resources and investment opportunities.
Whenever conflicts of interest arise, the portfolio manager will endeavor to exercise his discretion in a manner that he believes is equitable
to all interested persons. The investment adviser has adopted several policies and procedures designed to address these potential conflicts
including a code of ethics and policies that govern the investment adviser’s trading practices, including among other things the aggregation
and allocation of trades among clients, brokerage allocations, cross trades and best execution.

Calvert Mortgage Access Fund 14 SAI dated [______], 2022

 

The investment adviser operates proprietary indexes (each, an “Index”)
based on research and other information developed by the investment adviser. In addition, the investment adviser manages accounts (including
the Fund) using the same or substantially similar investment adviser research. The operation of the Indexes, the Fund and other accounts
in this manner may give rise to potential conflicts of interest, which may affect the management of the Fund and such accounts. For example,
the Fund may engage in purchases and sales of securities (including securities included in an Index) at different times prior to, during,
or after the time in which an Index is being reconstituted. The Indexes are reconstituted periodically as described in the prospectus.
The trading by the Fund and other accounts in securities that are part of an Index could impact the ability of the investment adviser’s
accounts that seeks to replicate the Index to do so in a timely manner. From time to time, the Funds may be restricted or otherwise limited
in trading in certain issuers in order to help ensure that accounts seeking to replicate an Index are able to do so.

Compensation
Structure for CRM.
Compensation of the investment adviser’s portfolio managers and other investment professionals has the
following primary components: (1) a base salary and (2) discretionary variable compensation that is comprised of cash bonus and depending
on eligibility, may also include deferred compensation consisting of restricted shares of Morgan Stanley stock and deferred cash that
are subject to a fixed vesting and distribution schedule. The investment adviser’s investment professionals also receive certain
retirement, insurance and other benefits that are broadly available to the investment adviser’s employees. Compensation of the investment
adviser’s investment professionals is reviewed primarily on an annual basis. Cash bonuses and deferred compensation awards, and
adjustments in base salary are typically paid or put into effect shortly after the December 31st fiscal year end of Morgan Stanley.

Method to
Determine Compensation.
The investment adviser compensates its portfolio managers based on company and team business results,
and individual performance, including the scale and complexity of their portfolio responsibilities and the total return performance of
managed funds and accounts versus the benchmark(s) stated in the prospectus, as well as an appropriate peer group (as described below).
In addition to rankings within peer groups of funds on the basis of absolute performance, consideration may also be given to relative
risk-adjusted performance. Risk-adjusted performance measures include, but are not limited to, the Sharpe ratio, which uses standard deviation
and excess return to determine reward per unit of risk. Fund performance is normally evaluated primarily versus peer groups of funds as
determined by Lipper Inc. and/or Morningstar, Inc. When a fund’s peer group as determined by Lipper or Morningstar is deemed by
the investment adviser’s management not to provide a fair comparison, performance may instead be evaluated primarily against a custom
peer group or market index. In evaluating the performance of a fund and its manager, primary emphasis is normally placed on three-year
performance, with secondary consideration of performance over longer and shorter periods. For funds that are tax-managed or otherwise
have an objective of after-tax returns, performance is measured net of taxes. For other funds, performance is evaluated on a pre-tax basis.
For funds with an investment objective other than total return (such as current income), consideration will also be given to the fund’s
success in achieving its objective. For managers responsible for multiple funds and accounts, investment performance is evaluated on an
aggregate basis, based on averages or weighted averages among managed funds and accounts. Funds and accounts that have performance-based
advisory fees are not accorded disproportionate weightings in measuring aggregate portfolio manager performance.

The compensation of portfolio managers with other job responsibilities
(such as heading an investment group or providing analytical support to other portfolios) will include consideration of the scope of such
responsibilities and the managers’ performance in meeting them.

The investment adviser seeks to compensate portfolio managers commensurate
with their responsibilities and performance, and competitive with other firms within the investment management industry. The investment
adviser participates in investment-industry compensation surveys and utilizes survey data as a factor in determining salary and variable
compensation levels for portfolio managers and other investment professionals. Salaries and variable compensation are also influenced
by the operating performance of the investment adviser and Morgan Stanley. While the salaries of the investment adviser’s portfolio
managers are comparatively fixed, variable compensation may fluctuate significantly from year to year, based on changes in company and
team performance, manager performance and other factors as described herein. For a high performing portfolio manager, variable compensation
may represent a substantial portion of total compensation.

Commodity
Futures Trading Commission Registration.
The CFTC has adopted certain regulations that subject registered investment companies
and advisers to regulation by the CFTC if a fund invests more than a prescribed level of its assets in certain CFTC-regulated instruments
(including futures, certain options and swaps agreements) or markets itself as providing investment exposure to such instruments. The
investment adviser has claimed an exclusion from the definition of “commodity pool operator” under the Commodity Exchange
Act with respect to its management of the Fund and the other funds it manages. Accordingly, neither the Fund nor the investment adviser
is subject to CFTC regulation. The CFTC has neither reviewed nor approved the Fund’s investment strategies or this SAI.

Calvert Mortgage Access Fund 15 SAI dated [______], 2022

Administrative
Services.
  As indicated in the Prospectus, CRM serves as administrator of the Fund under an Administrative Services Agreement.
The Fund is authorized to pay CRM an annual fee for providing administrative services to the Fund. Under the Administrative Services Agreement,
CRM has been engaged to administer the Fund’s affairs, subject to the supervision of the Board, and shall furnish office space and
all necessary office facilities, equipment and personnel for administering the affairs of the Fund.

Sub-Transfer
Agency Support Services.
Eaton Vance provides sub-transfer agency and related services to Calvert mutual funds pursuant to
a Sub-Transfer Agency Support Services Agreement. Under the agreement, Eaton Vance provides: (1) specified sub-transfer agency services;
(2) compliance monitoring services; and (3) intermediary oversight services. For the services it provides, Eaton Vance receives an aggregate
annual fee equal to the actual expenses incurred by Eaton Vance in the performance of such services.

Expenses. The Fund is
responsible for all expenses not expressly stated to be payable by another party (such as expenses required to be paid pursuant to an
agreement with the investment adviser, the principal underwriter or the administrator). In the case of expenses incurred by the Trust,
the Fund is responsible for its pro rata share of those expenses. Pursuant to the Amended and Restated Multiple Class Plan for Calvert
Funds, Fund expenses are allocated to each class on a pro rata basis, except that distribution and service fees are allocated exclusively
to the class that incurs them, and sub-accounting, recordkeeping and other similar fees are not allocated to (or incurred by) Class R6
shares.

OTHER SERVICE PROVIDERS

Principal
Underwriter.
Eaton Vance Distributors, Inc. (“EVD”), Two International Place, Boston, MA 02110 is the principal
underwriter of the Fund. The principal underwriter acts as principal in selling shares under a Distribution Agreement with the Trust.
The expenses of printing copies of prospectuses used to offer shares and other selling literature and of advertising are borne by the
principal underwriter. The fees and expenses of qualifying and registering and maintaining qualifications and registrations of the Fund
and its shares under federal and state securities laws are borne by the Fund. The Distribution Agreement is renewable annually by the
members of the Board (including a majority of the noninterested Trustees who have no direct or indirect financial interest in the operation
of the Distribution Agreement or any applicable Distribution Plan), may be terminated on sixty days’ notice either by such Trustees
or by vote of a majority of the outstanding Fund shares or on six months’ notice by the principal underwriter and is automatically
terminated upon assignment. The principal underwriter distributes shares on a “best efforts” basis under which it is required
to take and pay for only such shares as may be sold. Effective March 1, 2021, EVD is an indirect wholly owned subsidiary of Morgan Stanley.
Prior to March 1, 2021, EVD was a direct, wholly owned subsidiary of EVC.

Custodian.
State Street Bank and Trust Company (“State Street”), State Street Financial Center, One Lincoln Street, Boston, MA 02111,
serves as custodian to the Fund. State Street has custody of all cash and securities of the Fund, maintains the general ledger of the
Fund and computes the daily net asset value of shares of the Fund. In such capacity it attends to details in connection with the sale,
exchange, substitution, transfer or other dealings with the Fund’s investments, receives and disburses all funds and performs various
other ministerial duties upon receipt of proper instructions from the Trust. State Street also provides services in connection with the
preparation of shareholder reports and the electronic filing of such reports with the SEC.

Independent
Registered Public Accounting Firm.
[ ], independent registered public accounting firm, audits the Fund’s financial statements.
[ ] and/or its affiliates provide other audit and related services to the Fund.

Transfer
Agent.
DST Asset Manager Solutions, Inc. (“DST”), 2000 Crown Colony Drive, Quincy, MA 02169, serves as transfer
and dividend disbursing agent for the Fund.

CALCULATION OF NET ASSET VALUE

The net asset value of the Fund is determined by State Street (as agent
and custodian) by subtracting the liabilities of the Fund from the value of its total assets. The Fund is closed for business and will
not issue a net asset value on the following business holidays and any other business day that the Exchange is closed: New Year’s
Day, Martin Luther King, Jr. Day, Presidents’ Day, Good Friday, Memorial Day, Juneteenth, Independence Day, Labor Day, Thanksgiving
Day and Christmas Day. The Fund’s net asset value per share is readily accessible on the Calvert funds website (www.calvert.com).

The Board has approved procedures pursuant to which investments are
valued for purposes of determining the Fund’s net asset value. Listed below is a summary of the methods generally used to value
investments (some or all of which may be held by the Fund) under the procedures.

· Equity securities (including common stock, exchange-traded funds, closed-end funds, preferred equity securities, exchange-traded notes
and other instruments that trade on recognized stock exchanges) are valued at the last sale, official close or, if there are no reported
sales, at the mean between the bid and asked price on the primary exchange on which they are traded.

Calvert Mortgage Access Fund 16 SAI dated [______], 2022

· Most debt obligations are valued on the basis of market valuations furnished by a pricing service or at the mean of the bid and asked
prices provided by recognized broker/dealers of such securities. The pricing service may use a pricing matrix to determine valuation.
· Short-term instruments with remaining maturities of less than 397 days are valued on the basis of market valuations furnished by a
pricing service or based on dealer quotations.
· Foreign securities and currencies are valued in U.S. dollars based on foreign currency exchange quotations supplied by a pricing service.
· Senior and Junior Loans (as defined in the “Additional Information About Investment Strategies and Risks” section of this
SAI) are valued on the basis of prices furnished by a pricing service. The pricing service uses transactions and market quotations from
brokers in determining values.
· Futures contracts are valued at the settlement or closing price on the primary exchange or board of trade on which they are traded.
· Exchange-traded options are valued at the mean of the bid and asked prices. Over-the-counter options are valued based on quotations
obtained from a pricing service or from a broker (typically the counterparty to the option).
· Non-exchange traded derivatives (including swap agreements, forward contracts and equity participation notes) are generally valued
on the basis of valuations provided by a pricing service or using quotes provided by a broker/dealer (typically the counterparty) or,
for total return swaps, based on market index data.
· Precious metals are valued at the New York Composite mean quotation.
· Liabilities with a payment or maturity date of 364 days or less are stated at their principal value and longer dated liabilities generally
will be carried at their fair value.
· Valuations of foreign equity securities and total return swaps and exchange-traded futures contracts on non-North American equity
indices are generally based on fair valuation provided by a pricing service.

Investments which are unable to be valued in accordance with the foregoing
methodologies are valued at fair value using methods determined in good faith by or at the direction of the members of the Board. Such
methods may include consideration of relevant factors, including but not limited to (i) the type of security and the existence of any
contractual restrictions on the security’s disposition; (ii) the price and extent of public trading in similar securities of the
issuer or of comparable companies or entities; (iii) quotations or relevant information obtained from broker-dealers or other market participants;
(iv) information obtained from the issuer, analysts, and/or the appropriate stock exchange (for exchange-traded securities); (v) an analysis
of the company’s or entity’s financial statements; (vi) an evaluation of the forces that influence the issuer and the market(s)
in which the security is purchased and sold; (vii) any transaction involving the issuer of such securities; and (viii) any other factors
deemed relevant by the investment adviser. For purposes of fair valuation, the portfolio managers of one Calvert fund that invests in
Senior and Junior Loans may not possess the same information about a Senior or Junior Loan as the portfolio managers of another Calvert
fund. As such, at times the fair value of a Loan determined by certain Calvert portfolio managers may vary from the fair value of the
same Loan determined by other portfolio managers.

PURCHASING AND REDEEMING SHARES

Additional
Information About Purchases.
Fund shares are offered for sale only in states where they are registered. The U.S. registered
Calvert funds generally do not accept investments from residents of the European Union, the United Kingdom or Switzerland, although may
do so to the extent that the Calvert funds may be lawfully offered in a relevant jurisdiction (including at the initiative of the investor).
Fund shares are continuously offered through financial intermediaries which have entered into agreements with the principal underwriter.
Fund shares are sold at the public offering price, which is the net asset value next computed after receipt of an order plus the initial
sales charge, if any. The Fund receives the net asset value. The principal underwriter receives the sales charge, all or a portion of
which may be reallowed to the financial intermediaries responsible for selling Fund shares. The sales charge table for Class A shares
in the Prospectus is applicable to purchases of Class A shares of the Fund alone or in combination with purchases of certain other funds
offered by the principal underwriter, made at a single time by (i) an individual, or an individual, his or her spouse and their children
under the age of twenty-one, purchasing shares for his or their own account, and (ii) a trustee or other fiduciary purchasing shares for
a single trust estate or a single fiduciary account. The table is also presently applicable to (1) purchases of Class A shares pursuant
to a written Statement of Intention; or (2) purchases of Class A shares pursuant to the Right of Accumulation and declared as such at
the time of purchase. See “Sales Charges.”

Class I
Share Purchases.
 Class I shares are available for purchase by clients of financial intermediaries who (i) charge
such clients an ongoing fee for advisory, investment, consulting or similar services, or (ii) have entered into an agreement with
the principal underwriter to offer Class I shares through a no-load network or platform. Such clients may include individuals,
corporations, endowments, foundations and employer sponsored retirement plans. Class I shares may also be available through
brokerage platforms of broker-dealer firms that have agreements with a Fund’s principal underwriter to offer Class I shares
solely when acting as an agent for the investor. An investor acquiring Class I shares through such platforms may be required to pay
a commission and/or other forms of compensation to the broker. Class I shares also are offered to investment and institutional
clients of Calvert and its affiliates; certain persons affiliated with Calvert and its affiliates; current and retired members of
Calvert Fund Boards; employees of Calvert and its affiliates and such persons’ spouses, parents, siblings and lineal
descendants and their beneficial accounts.

Calvert Mortgage Access Fund 17 SAI dated [______], 2022

Waiver of
Investment Minimums.
 For classes other than Class R6, in addition to waivers described in the Prospectus, minimum investment
amounts are waived for individual plan participants in an employer sponsored retirement plan; current and retired members of Calvert Fund
Boards; clients (including custodial, agency, advisory and trust accounts) and current and retired officers and employees of Calvert,
its affiliates and other investment advisers and sub-advisers to the Calvert family of funds; and for such persons’ spouses, parents,
siblings and lineal descendants and their beneficial accounts. The minimum initial investment amount is also waived for officers and employees
of the Fund’s custodian and transfer agent and in connection with the merger (or similar transaction) of an investment company (or
series or class thereof) or personal holding company with the Fund (or class thereof). Investments in a Fund by ReFlow in connection with
the ReFlow liquidity program are also not subject to the minimum investment amount.

Suspension
of Sales.
The Trust may, in its absolute discretion, suspend, discontinue or limit the offering of one or more of its classes
of shares at any time. In determining whether any such action should be taken, the Trust’s management intends to consider all relevant
factors, including (without limitation) the size of the Fund or class, the investment climate and market conditions and the volume of
sales and redemptions of shares. The Class A and Class C Distribution Plan may continue in effect and payments may be made under the Plan
following any such suspension, discontinuance or limitation of the offering of shares; however, there is no obligation to continue the
Plan for any particular period of time. Suspension of the offering of shares would not, of course, affect a shareholder’s ability
to redeem shares.

Additional
Information About Redemptions.
The right to redeem shares of the Fund can be suspended and the payment of the redemption price
deferred when the Exchange is closed (other than for customary weekend and holiday closings), during periods when trading on the Exchange
is restricted as determined by the SEC, or during any emergency as determined by the SEC which makes it impracticable for the Fund to
dispose of its securities or value its assets, or during any other period permitted by order of the SEC for the protection of investors.

Due to the high cost of maintaining small accounts, the Trust reserves
the right to redeem accounts with balances of less than $750. Prior to such a redemption, shareholders will be given 60 days’ written
notice to make an additional purchase. No CDSC or redemption fees, if applicable, will be imposed with respect to such involuntary redemptions.

As disclosed in the Prospectus, the Fund typically expects to meet redemption
requests by (i) distributing any cash holdings, (ii) selling portfolio investments and/or (iii) borrowing from a bank under a line of
credit. In addition to the foregoing, the Fund also may distribute securities as payment (a so-called “redemption in-kind”),
in which case the redeeming shareholder may pay fees and commissions to convert the securities to cash. Unless requested by a shareholder,
the Fund generally expects to limit use of redemption in-kind to stressed market conditions, but reserves the right to do so at any time.
The Fund may decline a shareholder’s request to receive redemption proceeds in-kind. Any redemption in-kind would be made in accordance
with policies adopted by the Fund, which allow the Fund to distribute securities pro rata or as selected by the investment adviser.

The Fund participates in a committed senior secured 364-day revolving
line of credit, and may borrow amounts available thereunder for temporary purposes, such as meeting redemptions. The Fund may also borrow
for investment purposes. See “Additional Information about Investment Strategies and Risks – Borrowing for Temporary Purposes”
herein.

In connection with requests to re-issue uncashed checks representing
redemption proceeds, the Fund reserves the right to require the redeeming shareholder to provide Medallion signature guaranteed wire instructions
for delivery of redemption proceeds. Redemption proceeds represented by an uncashed check will not earn interest or other return during
such time.

As noted above, the Fund may pay the redemption price of shares of the
Fund, either totally or partially, by a distribution in-kind of securities. All requests for redemptions in-kind must be in good order.
Provided the redemption request is received by the Fund not later than 12:00 p.m. (Eastern Time) on the day of the redemption, the Fund
may in its discretion, if requested by a redeeming shareholder, provide the redeeming shareholders with an estimate of the securities
to be distributed. Any difference between the redemption value of the distributed securities and the value of the Fund shares redeemed
will be settled in cash. Securities distributed in a redemption in-kind would be valued pursuant to the Fund’s valuation procedures
and selected by the investment adviser. If a shareholder receives securities in a redemption in-kind, the shareholder could incur brokerage
or other charges in converting the securities to cash and the value of such securities would be subject to price fluctuations until sold.

Calvert Mortgage Access Fund 18 SAI dated [______], 2022

 

Pursuant to its Distribution Agreement with the Trust, the principal
underwriter is authorized to repurchase shares offered for redemption to the Fund from time to time and the Fund is authorized to pay
to the principal underwriter the purchase price for such repurchased shares, which shall be the net asset value next determined after
the repurchase order, subject to any applicable CDSC payable to the principal underwriter.

Systematic
Withdrawal Plan.
The transfer agent will send to the shareholder regular monthly or quarterly payments of any permitted amount
designated by the shareholder based upon the value of the shares held. The checks will be drawn from share redemptions and hence, may
require the recognition of taxable gain or loss. Income dividends and capital gains distributions in connection with withdrawal plan accounts
will be credited at net asset value as of the ex-dividend date for each distribution. Continued withdrawals in excess of current income
will eventually use up principal, particularly in a period of declining market prices. A shareholder may not have a withdrawal plan in
effect at the same time he or she has authorized Bank Automated Investing or is otherwise making regular purchases of Fund shares. The
shareholder, the transfer agent or the principal underwriter may terminate the withdrawal plan at any time without penalty.

Other Information. The
Fund’s net asset value per share is normally rounded to two decimal places. In certain situations (such as a merger, share split
or a purchase or sale of shares that represents a significant portion of a share class), the administrator may determine to extend the
calculation of the net asset value per share to additional decimal places to ensure that neither the value of the Fund nor a shareholder’s
shares is diluted materially as the result of a purchase or sale or other transaction.

SALES CHARGES

Dealer Commissions.
The principal underwriter may, from time to time, at its own expense, provide additional incentives to financial intermediaries which
employ registered representatives who sell Fund shares and/or shares of other funds distributed by the principal underwriter. In some
instances, such additional incentives may be offered only to certain financial intermediaries whose representatives sell or are expected
to sell significant amounts of shares. In addition, the principal underwriter may from time to time increase or decrease the sales commissions
payable to financial intermediaries. The principal underwriter may allow, upon notice to all financial intermediaries with whom it has
agreements, discounts up to the full sales charge during the periods specified in the notice. During periods when the discount includes
the full sales charge, such financial intermediaries may be deemed to be underwriters as that term is defined in the 1933 Act.

Purchases
at Net Asset Value. 
Class A shares may be sold at net asset value (without a sales charge) to clients of financial intermediaries
who (i) charge such clients an ongoing fee for advisory, investment, consulting or similar services, or (ii) have entered into an agreement
with the principal underwriter to offer Class A shares through a no-load network or platform; current and retired members of Calvert Fund
Boards; to clients (including custodial, agency, advisory and trust accounts) and current and former Directors, officers and employees
of Calvert, its affiliates and other investment advisers and sub-advisers of Calvert sponsored funds; and to such persons’ spouses,
parents, siblings and lineal descendants and their beneficial accounts. Such shares may also be issued at net asset value (1) in connection
with the merger (or similar transaction) of an investment company (or series or class thereof) or personal holding company with the Fund
(or class thereof), (2) to HSAs (Health Savings Accounts) and to employer sponsored retirement plans and trusts used to fund those plans,
(3) to officers and employees of the Fund’s custodian and transfer agent, (4) in connection with the ReFlow liquidity program and
(5) direct purchases of shares by accounts where no financial intermediary is specified. Class A shares may also be sold at net asset
value to registered representatives and employees of financial intermediaries. Class A shares are also offered at net asset value to shareholders
who make a permitted direct transfer or roll-over to a Calvert prototype individual retirement account (“IRA”) from an
employer-sponsored retirement plan previously invested in Calvert funds (applicable only to the portion previously invested in Calvert
funds), provided that sufficient documentation is provided to the transfer agent of such transfer or roll-over at the time of the account
opening. Sales charges generally are waived because either (i) there is no sales effort involved in the sale of shares or (ii) the investor
is paying a fee (other than the sales charge) to the financial intermediary involved in the sale. Any new or revised sales charge or CDSC
waiver will be prospective only. A financial intermediary may not, in accordance with its policies and procedures, offer one or more of
the waiver categories described above and shareholders should consult their financial intermediary for more information.

CDSC Waiver.
CDSCs will be waived in connection with redemptions from employer sponsored retirement plans or IRAs to satisfy required minimum distributions
by applying the rate required to be withdrawn under the applicable rules and regulations of the IRS to the balance of shares in your account.
CDSCs will also be waived in connection with returning excess contributions made to IRAs.

Statement
of Intention.
If it is anticipated that $50,000 or more of Class A shares and shares of other funds exchangeable for Class
A shares of another Calvert fund will be purchased within a 13-month period, the Statement of Intention section of the account application
should be completed so that shares may be obtained at the same reduced sales charge as though the total quantity were invested in one
lump sum. Shares eligible for the right of accumulation

Calvert Mortgage Access Fund 19 SAI dated [______], 2022

(see below) as of the date of the statement and purchased during the
13-month period will be included toward the completion of the statement. If you make a statement of intention, the transfer agent is authorized
to hold in escrow sufficient shares (5% of the dollar amount specified in the statement) which can be redeemed to make up any difference
in sales charge on the amount intended to be invested and the amount actually invested. A statement of intention does not obligate the
shareholder to purchase or the Fund to sell the full amount indicated in the statement.

If the amount actually purchased during the 13-month period is less
than that indicated in the statement, the shareholder will be requested to pay the difference between the sales charge applicable to the
shares purchased and the sales charge paid under the statement of intention. If the payment is not received in 20 days, the appropriate
number of escrowed shares will be redeemed in order to realize such difference. Shareholders will not receive a lower sales charge if
total purchases during the 13-month period are large enough to qualify for a lower sales charge than that applicable to the amount specified
in the statement. If the sales charge rate changes during the 13-month period, all shares purchased or charges assessed after the date
of such change will be subject to the then applicable sales charge.

Right of
Accumulation.
Under the right of accumulation, the applicable sales charge level is calculated by aggregating the dollar amount
of the current purchase and the value (calculated at the maximum current offering price) of Fund shares owned by the shareholder. The
sales charge on the Fund shares being purchased will then be applied at the rate applicable to the aggregate. Share purchases eligible
for the right of accumulation are described under “Sales Charges” in the Prospectus. For any such discount to be made available
at the time of purchase a purchaser or his or her financial intermediary must provide the principal underwriter (in the case of a purchase
made through a financial intermediary) or the transfer agent (in the case of an investment made by mail) with sufficient information to
permit verification that the purchase order qualifies for the accumulation privilege. Confirmation of the order is subject to such verification.
The right of accumulation privilege may be amended or terminated at any time as to purchases occurring thereafter.

Conversion
Feature.
Effective November 5, 2020 (the “Effective Date”), Class C shares automatically convert to Class A shares
during the month following the eight year anniversary of the purchase of such Class C shares. If the financial intermediary that maintains
a Class C shareholder’s account has not tracked the holding period for Class C shares, Class C shares held as of the Effective Date
will automatically convert to Class A shares eight years after the Effective Date. Such conversion shall be effected on the basis of the
relative NAVs per share of the two classes without the imposition of any sales charge, fee or other charge. For purposes of this conversion,
all distributions paid on such Class C shares which the shareholder elects to reinvest in Class C shares will be considered to be held
in a separate sub-account. Upon the conversion of Class C shares not acquired through the reinvestment of distributions, a pro rata portion
of the Class C shares held in the sub-account will also convert to such Class A shares. This portion will be determined by the ratio that
such Class C shares being converted bears to the total of Class C shares (excluding shares acquired through reinvestment) in the account.

Distribution Plans

The Trust has in effect a compensation-type Distribution Plan for Class
A shares (the “Class A Plan”) adopted pursuant to Rule 12b-1 under the 1940 Act. The Class A Plan is designed to (i) finance
activities which are primarily intended to result in the distribution and sales of Class A shares and to make payments in connection with
the distribution of such shares and (ii) pay service fees for personal services and/or the maintenance of shareholder accounts to the
principal underwriter, financial intermediaries and other persons. The distribution and service fees payable under the Class A Plan shall
not exceed 0.25% of the average daily net assets attributable to Class A shares for any fiscal year. Class A distribution and service
fees are paid monthly in arrears. For the distribution and service fees paid by Class A shares, see Appendix A.

The Trust/Corporation also has in effect a compensation-type Distribution
Plan for Class C shares (the “Class C Plan”) adopted pursuant to Rule 12b-1 under the 1940 Act. Pursuant to the Class C Plan,
Class C pays the principal underwriter a distribution fee, accrued daily and paid monthly, at an annual rate not exceeding 0.75% of its
average daily net assets to finance the distribution of its shares. Such fees compensate the principal underwriter for the sales commissions
paid by it to financial intermediaries on the sale of shares, for other distribution expenses (such as personnel, overhead, travel, printing
and postage) and for interest expense. The principal underwriter is entitled to receive all distribution fees and CDSCs paid or payable
with respect to Class C shares, provided that no such payments will be made that would cause the Class to exceed the maximum sales charge
permitted by FINRA Rule 2341(d).

The Class C Plan also authorizes the payment of service fees to
the principal underwriter, financial intermediaries and other persons in amounts not exceeding an annual rate of 0.25% of its average
daily net assets for personal services, and/or the maintenance of shareholder accounts. For Class C, financial intermediaries currently
generally receive (a) a service fee (except on exchange transactions and reinvestments) at the time of sale equal to 0.25% of the purchase
price of Class C shares sold by such intermediaries, and (b) monthly service fees approximately equivalent to 1/12 of 0.25% of the value
of Class C shares sold by such intermediaries. During the first year after a purchase of Class C shares, the principal underwriter will retain the service fee as reimbursement for
the service fee payment made to financial intermediaries at the time of sale (if applicable). For the service fees paid, see Appendix
B.

Calvert Mortgage Access Fund 20 SAI dated [______], 2022

The Board believes that the Plan will be a significant factor in the
expected growth of the Fund’s assets, and will result in increased investment flexibility and advantages which have benefitted and
will continue to benefit the Fund and its shareholders. The Calvert organization may profit by reason of the operation of a Plan through
an increase in Fund assets and if at any point in time the aggregate amounts received by the principal underwriter pursuant to a Plan
exceeds the total expenses incurred in distributing Fund shares. For sales commissions and CDSCs, if applicable, see Appendix A and Appendix
B.

A Plan continues in effect from year to year so long as such continuance
is approved at least annually by the vote of both a majority of (i) the noninterested Trustees of the Trust who have no direct or indirect
financial interest in the operation of the Plan or any agreements related to the Plan (the “Plan Trustees”) and (ii) all of
the Trustees then in office. A Plan may be terminated at any time by vote of a majority of the Plan Trustees or by a vote of a majority
of the outstanding voting securities of the applicable Class. Quarterly Board member review of a written report of the amount expended
under the Plan and the purposes for which such expenditures were made is required. A Plan may not be amended to increase materially the
payments described therein without approval of the shareholders of the affected Class and the Board. So long as a Plan is in effect, the
selection and nomination of the noninterested Trustees shall be committed to the discretion of such Trustees. The Trustees, including
the Plan Trustees, initially approved the current Plan(s) on [March 9, 2022]. Any Board member who is an “interested” person
of the Trust has an indirect financial interest in a Plan because his or her employer (or affiliates thereof) receives distribution and/or
service fees under the Plan or agreements related thereto.

DISCLOSURE OF PORTFOLIO HOLDINGS AND RELATED
INFORMATION

The Board has adopted policies and procedures (the “Policies”)
with respect to the disclosure of information about portfolio holdings of the Fund. See the Fund’s Prospectus for information on disclosure
made in filings with the SEC and/or posted on the Calvert website (www.calvert.com) and disclosure of certain portfolio characteristics.
Pursuant to the Policies, information about portfolio holdings of the Fund may also be disclosed as follows:

· Confidential disclosure for a legitimate Fund purpose: Portfolio
holdings may be disclosed, from time to time as necessary, for a legitimate business purpose of the Fund, believed to be in the best interests
of the Fund and its shareholders, provided there is a duty or an agreement that the information be kept confidential. Any such confidentiality
agreement includes provisions intended to impose a duty not to trade on the non-public information. The Policies permit disclosure of
portfolio holdings information to the following: 1) affiliated and unaffiliated service providers that have a legal or contractual duty
to keep such information confidential, such as employees of the investment adviser (including portfolio managers), the administrator,
custodian, transfer agent, principal underwriter, etc. described herein and in the Prospectus; 2) other persons who owe a fiduciary or
other duty of trust or confidence to the Fund (such as Fund legal counsel and independent registered public accounting firm); or 3) persons
to whom the disclosure is made in advancement of a legitimate business purpose of the Fund and who have expressly agreed in writing to
maintain the disclosed information in confidence and to use it only in connection with the legitimate business purpose underlying the
arrangement. To the extent applicable to a Calvert fund, such persons may include securities lending agents which may receive information
from time to time regarding selected holdings which may be loaned by a Fund, in the event a Fund is rated, credit rating agencies (Moody’s
Investor Services, Inc. and S&P Global Ratings), analytical service providers engaged by the investment adviser (SS&C Advent,
Bloomberg L.P., Evare, FactSet, McMunn Associates, Inc., MSCI/Barra and The Yield Book, Inc.), proxy evaluation vendors (Institutional
Shareholder Services Inc.), pricing services (Refinitiv Evaluated Pricing Service, WM/Reuters Information Services and Non-Deliverable
Forward Rates Service, IHS Markit, FT Interactive Data Corp., Securities Evaluations, Inc., SuperDerivatives and StatPro.), which receive
information as needed to price a particular holding, translation services, third-party reconciliation services, lenders under Fund credit
facilities (State Street and its affiliates), consultants and other product evaluators (Morgan Stanley Smith Barney LLC), other service
providers (Morgan Stanley Investment Management), engagement consultants (Hermes Equity Ownership Services Limited) and, for purposes
of facilitating portfolio transactions, financial intermediaries and other intermediaries (national and regional municipal bond dealers
and mortgage-backed securities dealers). These entities receive portfolio information on an as needed basis in order to perform the service
for which they are being engaged. If required in order to perform their duties, this information will be provided in real time or as soon
as practical thereafter. Additional categories of disclosure involving a legitimate business purpose may be added to this list upon the
authorization of the Fund’s Board. In addition to the foregoing, disclosure of portfolio holdings may be made to the Fund’s
investment adviser as a seed investor in a fund, in order for the adviser or its parent to satisfy certain reporting obligations and reduce
its exposure to market risk factors associated with any such seed investment. Also, in connection with a redemption in-kind, the redeeming
shareholders may be required to agree to keep the information about the securities to be so distributed confidential, except to the extent
necessary to dispose of the securities.

Calvert Mortgage Access Fund 21 SAI dated [______], 2022

· Historical portfolio holdings information: From time to time,
the Fund may be requested to provide historic portfolio holdings information or certain characteristics of portfolio holdings that have
not been made public previously. In such case, the requested information may be provided if: the information is requested for due diligence
or another legitimate purpose; the requested portfolio holdings or portfolio characteristics are for a period that is no more recent than
the date of the portfolio holdings or portfolio characteristics posted to the Calvert website; and the dissemination of the requested
information is reviewed and approved in accordance with the Policies.

The Fund, the investment adviser and principal underwriter will not
receive any monetary or other consideration in connection with the disclosure of information concerning the Fund’s portfolio holdings.

The Policies may not be waived, or exception made, without the consent
of the CCO of the Fund. The CCO may not waive or make exception to the Policies unless such waiver or exception is consistent with the
intent of the Policies, which is to ensure that disclosure of portfolio information is in the best interest of Fund shareholders. In determining
whether to permit a waiver of or exception to the Policies, the CCO will consider whether the proposed disclosure serves a legitimate
purpose of the Fund, whether it could provide the recipient with an advantage over Fund shareholders or whether the proposed disclosure
gives rise to a conflict of interest between the Fund’s shareholders and its investment adviser, principal underwriter or other
affiliated person. The CCO will report all waivers of or exceptions to the Policies to the Board at their next meeting. The Board may
impose additional restrictions on the disclosure of portfolio holdings information at any time.

The Policies are designed to provide useful information concerning the
Fund to existing and prospective Fund shareholders while at the same time inhibiting the improper use of portfolio holdings information
in trading Fund shares and/or portfolio securities held by the Fund. However, there can be no assurance that the provision of any portfolio
holdings information is not susceptible to inappropriate uses (such as the development of “market timing” models), particularly
in the hands of highly sophisticated investors, or that it will not in fact be used in such ways beyond the control of the Fund.

TAXES

The following is a summary of some of the tax consequences affecting
the Fund and its shareholders. As used below, “the Fund” refers to each Fund listed on the cover of this SAI, except as otherwise
noted. The summary does not address all of the special tax rules applicable to certain classes of investors, such as individual retirement
accounts and employer sponsored retirement plans, tax-exempt entities, foreign investors, insurance companies and financial institutions.
Shareholders should consult their own tax advisors with respect to special tax rules that may apply in their particular situations, as
well as the federal, state, local, and, where applicable, foreign tax consequences of investing in the Fund.

Taxation
of the Fund.
The Fund, as a series of the Trust, is treated as a separate entity for federal income tax purposes. The Fund
has elected to be treated and intends to qualify each year as a regulated investment company (“RIC”) under Subchapter M of
the Code. Accordingly, the Fund intends to satisfy certain requirements relating to sources of its income and diversification of its assets
and to distribute substantially all of its net investment income (including tax-exempt income, if any) and net short-term and long-term
capital gains (after reduction by any available capital loss carryforwards) in accordance with the timing requirements imposed by the
Code, so as to maintain its RIC status and to avoid paying any federal income tax. Based on advice of counsel, the Fund generally will
not recognize gain or loss on its distribution of appreciated securities in shareholder-initiated redemptions of its shares. If the Fund
qualifies for treatment as a RIC and satisfies the above-mentioned distribution requirements, it will not be subject to federal income
tax on income paid to its shareholders in the form of dividends or capital gain distributions. The Fund intends to qualify as a RIC for
its current taxable year.

The Fund also seeks to avoid the imposition of a federal excise tax
on its ordinary income and capital gain net income. However, if the Fund fails to distribute in a calendar year substantially all of its
ordinary income for such year and substantially all of its capital gain net income for the one-year period ending October 31 (or later
if the Fund is permitted to so elect and so elects), plus any retained amount from the prior year, the Fund will be subject to a 4% excise
tax on the undistributed amounts. In order to avoid incurring a federal excise tax obligation, the Code requires that the Fund distribute
(or be deemed to have distributed) by December 31 of each calendar year (i) at least 98% of its ordinary income (excluding tax-exempt
income, if any) for such year, (ii) at least 98.2% of its capital gain net income (which is the excess of its realized capital gains over
its realized capital losses), generally computed on the basis of the one-year period ending on October 31 of such year (or November 30
or December 31, if the Fund makes the election referred to above), after reduction by any available capital loss carryforwards, and (iii)
100% of any income and capital gains from the prior year (as previously computed) that were not distributed out during such year and on
which the Fund paid no federal income tax. If the Fund fails to meet these requirements it will be subject to a nondeductible 4% excise
tax on the undistributed amounts. Under current law, provided that the Fund qualifies as a RIC, the Fund should not be liable for any
applicable state income, corporate excise or franchise tax.

Calvert Mortgage Access Fund 22 SAI dated [______], 2022

If the Fund does not qualify as a RIC for any taxable year, the Fund’s
taxable income will be subject to corporate income taxes, and all distributions from earnings and profits, including distributions of
tax-exempt income and net capital gain (if any), will be taxable to the shareholder as dividend income. However, such distributions may
be eligible (i) to be treated as qualified dividend income in the case of shareholders taxed as individuals and (ii) for the dividends-received
deduction in the case of corporate shareholders, provided, in both cases, the shareholder meets certain holding period and other requirements
in respect of the Fund’s shares. In addition, in order to re-qualify for taxation as a RIC, the Fund may be required to recognize
unrealized gains, pay substantial taxes and interest, and make substantial distributions.

In certain situations, the Fund may, for a taxable year, elect to defer
all or a portion of its net capital losses (or if there is no net capital loss, then any net long-term or short-term capital loss) realized
after October and its late-year ordinary losses (generally, the sum of its (i) net ordinary loss from the sale, exchange or other taxable
disposition of property, attributable to the portion of the taxable year after October 31, and its (ii) other net ordinary loss attributable
to the portion of the taxable year after December 31) until the next taxable year in computing its investment
company taxable income and net capital gain, which will defer the recognition of such realized losses. Such deferrals and other rules
regarding gains and losses realized after October (or December) may affect the tax character of shareholder distributions.

Tax Consequences
of Certain Investments.
The following summary of the tax consequences of certain types of investments applies to the Fund.
References below to “the Fund” are to any Fund that can engage in the particular practice as described in the prospectus or
SAI.

Securities
Acquired at Market Discount or with Original Issue Discount.
Investment in securities acquired in zero coupon, deferred
interest, payment-in-kind and certain other securities with original issue discount, generally may cause the Fund to realize income prior
to the receipt of cash payments with respect to these securities. Such income will be accrued daily by the Fund and, in order to avoid
a tax payable by the Fund, the Fund may be required to liquidate securities that it might otherwise have continued to hold in order to
generate cash so that the Fund may make required distributions to its shareholders. Generally any gain recognized on the disposition of,
and any partial payment of principal on, a debt security having market discount is treated as ordinary income to the extent the gain,
or principal payment, does not exceed the “accrued market discount” on such debt security; alternatively, the Fund may elect
to accrue market discount currently, in which case the Fund will be required to include the accrued market discount in the Fund’s income
(as ordinary income) and thus distribute it over the term of the debt security, even though payment of that amount is not received until
a later time, upon partial or full repayment or disposition of the debt security; and the rate at which the market discount accrues, and
thus is included in the Fund’s income, will depend upon which of the permitted accrual methods the Fund elects.

Lower
Rated or Defaulted Securities.
Investments in securities that are at risk of, or are in, default present special tax issues
for the Fund. Tax rules are not entirely clear about issues such as when the Fund may cease to accrue interest, original issue discount
or market discount, when and to what extent deductions may be taken for bad debts or worthless securities and how payments received on
obligations in default should be allocated between principal and income.

Municipal
Obligations.
Any recognized gain or income attributable to market discount on long-term tax-exempt municipal obligations
(i.e., obligations with a term of more than one year) purchased after April 30, 1993 (except to the extent of a portion of the discount
on the obligations attributable to original issue discount) is taxable as ordinary income. A long-term debt obligation is generally treated
as acquired at a market discount if purchased after its original issue at a price less than (i) the stated principal amount payable at
maturity, in the case of an obligation that does not have original issue discount or (ii) in the case of an obligation that does have
original issue discount, the sum of the issue price and any original issue discount that accrued before the obligation was purchased,
subject to a de minimis exclusion.

From time to time proposals have been introduced before Congress for
the purpose of restricting or eliminating the federal income tax exemption for interest on certain types of municipal obligations, and
it can be expected that similar proposals may be introduced in the future. As a result of any such future legislation, the availability
of municipal obligations for investment by the Fund and the value of the securities held by it may be affected. It is possible that events
occurring after the date of issuance of municipal obligations, or after the Fund’s acquisition of such an obligation, may result
in a determination that the interest paid on that obligation is taxable, even retroactively.

Tax Credit
Bonds.
If the Fund holds, directly or indirectly, one or more tax credit bonds issued on or before December 31, 2017 (including
Build America Bonds, clean renewable energy bonds and other qualified tax credit bonds) on one or more applicable dates during a taxable
year, the Fund may elect to permit its shareholders to claim a tax credit
on their income tax returns equal to each shareholder’s proportionate share of tax credits from the applicable bonds that otherwise
would be allowed to the Fund. In such a case, shareholders must include in gross income (as interest) their proportionate share of the
income attributable to their proportionate share of those offsetting tax credits. A shareholder’s ability to claim a tax credit
associated with one or more tax credit bonds may be subject to certain limitations imposed by the Code. Even if the
Fund is eligible to pass through tax credits to shareholders, the Fund may choose not to do so.

Calvert Mortgage Access Fund 23 SAI dated [______], 2022

Derivatives.
The Fund’s investments in options, futures contracts, hedging transactions, forward contracts (to the extent permitted) and certain
other transactions may be subject to special tax rules (including mark-to-market, constructive sale, straddle, wash sale, short sale and
other rules), the effect of which may be to accelerate income to the Fund, defer Fund losses, cause adjustments in the holding periods
of Fund securities, convert capital gain into ordinary income and convert short-term capital losses into long-term capital losses. These
rules could therefore affect the amount, timing and character of Fund distributions.

Investments in “section 1256 contracts,” such
as regulated futures contracts, most foreign currency forward contracts traded in the interbank market and options on most stock indices,
are subject to special tax rules. All “section 1256 contracts” held by the Fund at the end of its taxable year are required
to be marked to their market value, and any unrealized gain or loss on those positions will be included in the Fund’s income as
if each position had been sold for its fair market value at the end of the taxable year. The resulting gain or loss will be combined with
any gain or loss realized by the Fund from positions in “section 1256 contracts” closed during the taxable year. Provided
such positions were held as capital assets and were not part of a “hedging transaction” nor part of a “straddle,”
60% of the resulting net gain or loss will be treated as long-term capital gain or loss, and 40% of such net gain or loss will be treated
as short-term capital gain or loss, regardless of the period of time the positions were actually held by the Fund. Unless an election
is made, net section 1256 gain or loss on forward currency contracts will be treated as ordinary income or loss.

Fund positions in index options that do not qualify as “section
1256 contracts” under the Code generally will be treated as equity options governed by Code Section 1234. Pursuant to Code Section
1234, if a written option expires unexercised, the premium received by the Fund is short-term capital gain to the Fund. If the Fund enters
into a closing transaction with respect to a written option, the difference between the premium received and the amount paid to close
out its position is short-term capital gain or loss. If an option written by the Fund that is not a “section 1256 contract”
is cash settled, any resulting gain or loss will be short-term capital gain. For an option purchased by the Fund that is not a “section
1256 contract”, any gain or loss resulting from sale of the option will be a capital gain or loss, and will be short-term or long-term,
depending upon the holding period for the option. If the option expires, the resulting loss is a capital loss and is short-term or long-term,
depending upon the holding period for the option. If a put option written by the Fund is exercised and physically settled, the premium
received is treated as a reduction in the amount paid to acquire the underlying securities, increasing the gain or decreasing the loss
to be realized by the Fund upon sale of the securities. If a call option written by the Fund is exercised and physically settled, the
premium received is included in the sale proceeds, increasing the gain or decreasing the loss realized by the Fund at the time of option
exercise.

As a result of entering into swap contracts, the Fund may make or receive
periodic net payments. The Fund may also make or receive a payment when a swap is terminated prior to maturity through an assignment of
the swap or other closing transaction. Periodic net payments will generally constitute ordinary income or deductions, while termination
of a swap will generally result in capital gain or loss (which will be a long-term capital gain or loss if the Fund has been a party to
a swap for more than one year). With respect to certain types of swaps, the Fund may be required to currently recognize income or loss
with respect to future payments on such swaps or may elect under certain circumstances to mark such swaps to market annually for tax purposes
as ordinary income or loss.

Short
Sales.
In general, gain or loss on a short sale is recognized when the Fund closes the sale by delivering the borrowed
property to the lender, not when the borrowed property is sold. Gain or loss from a short sale is generally considered to be capital gain
or loss to the extent that the property used to close the short sale constitutes a capital asset in the Fund’s hands. Except with
respect to certain situations where the property used to close a short sale has a long-term holding period on the date of the short sale,
special rules generally treat the gains on short sales as short-term capital gains. These rules may also terminate the running of the
holding period of “substantially identical property” held by the Fund. Moreover, a loss on a short sale will be treated as
a long-term capital loss if, on the date of the short sale, “substantially identical property” has been held by the Fund for
more than one year. In general, the Fund will not be permitted to deduct payments made to reimburse the lender of securities for dividends
paid on borrowed stock if the short sale is closed on or before the 45th day after the short sale is entered.

Constructive
Sales.
The Fund may recognize gain (but not loss) from a constructive sale of certain “appreciated financial positions”
if the Fund enters into a short sale, offsetting notional principal contract, or forward contract transaction with respect to the appreciated
position or substantially identical property. Appreciated financial positions subject to this constructive sale treatment include interests
(including options and forward contracts and short sales) in stock and certain other instruments. Constructive sale treatment does not
apply if the transaction is closed out not later than thirty days after the end of the taxable year in which the transaction was initiated,
and the underlying appreciated securities position is held unhedged for at least the next sixty days after the hedging transaction is
closed.

Calvert Mortgage Access Fund 24 SAI dated [______], 2022

Gain or loss on a short sale will generally not be realized until such
time as the short sale is closed. However, as described above in the discussion of constructive sales, if the Fund holds a short sale
position with respect to securities that has appreciated in value, and it then acquires property that is the same as or substantially
identical to the property sold short, the Fund generally will recognize gain on the date it acquires such property as if the short sale
were closed on such date with such property. Similarly, if the Fund holds an appreciated financial position with respect to securities
and then enters into a short sale with respect to the same or substantially identical property, the Fund generally will recognize gain
as if the appreciated financial position were sold at its fair market value on the date it enters into the short sale. The subsequent
holding period for any appreciated financial position that is subject to these constructive sale rules will be determined as if such position
were acquired on the date of the constructive sale.

Foreign
Investments and Currencies.
The Fund’s investments in foreign securities may be subject to foreign withholding
taxes or other foreign taxes with respect to income (possibly including, in some cases, capital gains), which would decrease the
Fund’s income on such securities. These taxes may be reduced or eliminated under the terms of an applicable U.S. income tax
treaty. If more than 50% of Fund assets at year end consists of the debt and equity securities of foreign corporations, the Fund may
elect to permit shareholders to claim a credit or deduction on their income tax returns for their pro rata portion of qualified
taxes paid by the Fund to foreign countries. If the election is made, shareholders will include in gross income from foreign sources
their pro rata share of such taxes. A shareholder’s ability to claim a foreign tax credit or deduction in respect of
foreign taxes paid by the Fund may be subject to certain limitations imposed by the Code (including a holding period requirement
applied at the Fund level, shareholder level and, if applicable, Portfolio level), as a result of which a shareholder may not
get a full credit or deduction for the amount of such taxes. In particular, the Fund or Portfolio, if applicable, must own a
dividend-paying stock for more than 15 days during the 31-day period beginning 15 days prior to the ex-dividend date in order to
pass through to shareholders a credit or deduction for any foreign withholding tax on a dividend paid with respect to such stock.
Likewise, shareholders must hold their Fund shares (without protection from risk or loss) on the ex-dividend date and for at least
15 additional days during the 31-day period beginning 15 days prior to the ex-dividend date to be eligible to claim the foreign tax
credit or deduction with respect to a given dividend. Shareholders who do not itemize deductions on their federal income tax returns
may claim a credit (but no deduction) for such taxes. Individual shareholders subject to the alternative minimum tax
(“AMT”) may not deduct such taxes for AMT purposes.

Transactions in foreign currencies, foreign currency-denominated debt
securities and certain foreign currency options, futures contracts, forward contracts and similar instruments (to the extent permitted)
may give rise to ordinary income or loss to the extent such income or loss results from fluctuations in the value of the foreign currency.
Under Section 988 of the Code, gains or losses attributable to fluctuations in exchange rates between the time the Fund accrues income
or receivables or expenses or other liabilities denominated in a foreign currency and the time the Fund actually collects such income
or pays such liabilities are generally treated as ordinary income or ordinary loss.

Investments in PFICs could subject the Fund to U.S. federal income tax
or other charges on certain distributions from such companies and on disposition of investments in such companies; however, the tax effects
of such investments may be mitigated by making an election to mark such investments to market annually or treat the PFIC as a “qualified
electing fund”. If the Fund were to invest in a PFIC and elect to treat the PFIC as a “qualified electing fund” under
the Code, the Fund might be required to include in income each year a portion of the ordinary earnings and net capital gains of the qualified
electing fund, even if not distributed to the Fund, and such amounts would be subject to the distribution requirements described above.
In order to make this election, the Fund would be required to obtain certain annual information from the PFICs in which it invests, which
may be difficult or impossible to obtain. Alternatively, if the Fund were to make a mark-to-market election with respect to a PFIC, the
Fund would be treated as if it had sold and repurchased the PFIC stock at the end of each year. In such case, the Fund would report any
such gains as ordinary income and would deduct any such losses as ordinary losses to the extent of previously recognized gains. This election
must be made separately for each PFIC, and once made, would be effective for all subsequent taxable years unless revoked with the consent
of the IRS. The Fund may be required to recognize income in excess of the distributions it receives from PFICs and its proceeds from dispositions
of PFIC stock in any particular year. As a result, the Fund may have to distribute this “phantom” income and gain to satisfy
the distribution requirement and to avoid imposition of the 4% excise tax.

U.S. Government
Securities.
Distributions paid by the Fund that are derived from interest on obligations of the U.S. Government and certain
of its agencies and instrumentalities (but generally not distributions of capital gains realized upon the disposition of such obligations)
may be exempt from state and local income taxes. The Fund generally intends to advise shareholders of the extent, if any, to which its
distributions consist of such interest. Shareholders are urged to consult their tax advisors regarding the possible exclusion of such
portion of their dividends for state and local income tax purposes.

Calvert Mortgage Access Fund 25 SAI dated [______], 2022

 

Real Estate
Investment Trusts (“REITs”).
Any investment by the Fund in equity securities of a REIT qualifying as such under
Subchapter M of the Code may result in the Fund’s receipt of cash in excess of the REIT’s earnings; if the Fund distributes
these amounts, these distributions could constitute a return of capital to Fund shareholders for U.S. federal income tax purposes. Dividends
received by the Fund from a REIT will not qualify for the corporate dividends-received deduction and generally will not constitute qualified
dividend income.

Distributions by the Fund to its shareholders that the Fund properly
reports as “section 199A dividends,” as defined and subject to certain conditions described below, are treated as qualified
REIT dividends in the hands of non-corporate shareholders. Non-corporate shareholders are permitted a federal income tax deduction equal
to 20% of qualified REIT dividends received by them, subject to certain limitations. Very generally, a “section 199A dividend”
is any dividend or portion thereof that is attributable to certain dividends received by a RIC from REITs, to the extent such dividends
are properly reported as such by the RIC in a written notice to its shareholders. A section 199A dividend is treated as a qualified REIT
dividend only if the shareholder receiving such dividend holds the dividend-paying RIC shares for at least 46 days of the 91-day period
beginning 45 days before the shares become ex-dividend, and is not under an obligation to make related payments with respect to a position
in substantially similar or related property. The Fund is permitted to report such part of its dividends as section 199A dividends as
are eligible, but is not required to do so.

Subject to any future regulatory guidance to the contrary, any distribution
of income attributable to qualified publicly traded partnership income from a Fund’s investment in a qualified publicly traded partnership
will not qualify for the deduction that would be available to a non-corporate shareholder were the shareholder to own such qualified publicly
traded partnership interest directly.

Inflation-Indexed
Bonds.
  Periodic adjustments for inflation to the principal amount of an inflation-indexed bond may give rise to original
issue discount, which will be includable in the Fund’s gross income (see “Securities Acquired at Market Discount or with Original
Issue Discount” above).  Also, if the principal value of an inflation-indexed bond is adjusted downward due to deflation, amounts
previously distributed in the taxable year may be characterized in some circumstances as a return of capital (see “Taxation of Fund
Shareholders” below).

Taxation
of Fund Shareholders.
Subject to the discussion of distributions of tax-exempt income below, Fund distributions of investment
income and net gains from investments held for one year or less will be taxable as ordinary income. Fund distributions of net gains from
investments held for more than one year and that are properly reported by the Fund as capital gain dividends are generally taxable as
long-term capital gains. The IRS and the Department of Treasury have issued regulations that impose special rules in respect of capital
gain dividends received through partnership interests constituting “applicable partnership interests” under Section 1061 of
the Code. Taxes on distributions of capital gains are determined by how long the Fund owned (or is treated as having owned) the investments
that generated the gains, rather than how long a shareholder has owned his or her shares in the Fund. Dividends and distributions
on the Fund’s shares are generally subject to federal income tax as described herein to the extent they are made out of the Fund’s
earnings and profits, even though such dividends and distributions may economically represent a return of a particular shareholder’s
investment. Such distributions are likely to occur in respect of shares purchased at a time when the Fund’s net asset value reflects
gains that are either unrealized, or realized but not distributed. Such realized gains may be required to be distributed even when the
Fund’s net asset value also reflects unrealized losses.

Distributions paid by the Fund during any period may be more or less
than the amount of net investment income and capital gains actually earned during the period. If the Fund makes a distribution to a shareholder
in excess of the Fund’s current and accumulated earnings and profits in any taxable year, the excess distribution will be treated
as a return of capital. A return of capital is not taxable, but it reduces a shareholder’s tax basis in its shares, thus reducing
any loss or increasing any gain on a subsequent taxable disposition by the shareholder of its shares. A shareholder’s tax basis
cannot go below zero and any return of capital in excess of a shareholder’s tax basis will be treated as capital gain.

Ordinarily, shareholders are required to take taxable distributions
by the Fund into account in the year in which the distributions are made. However, for federal income tax purposes, dividends that are
declared by the Fund in October, November or December as of a record date in such month and actually paid in January of the following
year will be treated as if they were paid on December 31 of the year declared. Therefore, such dividends will generally be taxable to
a shareholder in the year declared rather than in the year paid.

The amount of distributions payable by the Fund may vary depending on
general economic and market conditions, the composition of investments, current management strategy and Fund operating expenses. The Fund
will inform shareholders of the tax character of distributions annually to facilitate shareholder tax reporting.

The Fund may elect to retain its net capital gain, in which case the
Fund will be taxed thereon (except to the extent of any available capital loss carryovers) at regular corporate tax rates. In such a case,
it is expected that the Fund also will elect to have shareholders of record on the last day of its taxable year treated as if each received
a distribution of its pro rata share of such gain, with the result that each shareholder will be required to report its pro rata share
of such gain on its tax return as long-term capital gain, will receive a refundable tax credit for its pro rata share of tax paid by the
Fund on the gain, and will increase the tax basis for its shares by an amount equal
to the deemed distribution less the tax credit. The Fund is not required to, and there can be no assurance the Fund will, make this designation
if it retains all or a portion of its net capital gain in a taxable year.

Calvert Mortgage Access Fund 26 SAI dated [______], 2022

Any Fund distribution, other than dividends that are declared by the
Fund on a daily basis, will have the effect of reducing the per share net asset value of Fund shares by the amount of the distribution.
If a shareholder buys shares when the Fund has unrealized or realized but not yet distributed ordinary income or capital gains, the
shareholder will pay full price for the shares and then may receive a portion back as a taxable distribution even though such distribution
may economically represent a return of the shareholder’s investment.

Tax-Exempt
Income.
Distributions by the Fund of net tax-exempt interest income that are properly reported as “exempt-interest
dividends” may be treated by shareholders as interest excludable from gross income for federal income tax purposes under Section
103(a) of the Code. In order for the Fund to be entitled to pay the tax-exempt interest income as exempt-interest dividends to its shareholders,
the Fund must satisfy certain requirements, including the requirement that, at the close of each quarter of its taxable year, at least
50% of the value of its total assets consists of obligations the interest on which is exempt from regular federal income tax under Code
Section 103(a). Interest on certain municipal obligations may be taxable for purposes of the federal AMT for non-corporate and for state
and local purposes. Fund shareholders are required to report tax-exempt interest on their federal income tax returns.

Exempt-interest dividends received from the Fund are taken into
account in determining, and may increase, the portion of social security and certain railroad retirement benefits that may be
subject to federal income tax. Interest on indebtedness incurred by a shareholder to purchase or carry Fund shares that
distributes exempt-interest dividends will not be deductible for U.S. federal income tax purposes in proportion to the percentage
that the Fund’s distributions of exempt-interest dividends bears to all of the Fund’s distributions, excluding properly
reported capital gain dividends. If a shareholder receives exempt-interest dividends with respect to any Fund share and if the
share is held by the shareholder for six months or less, then any loss on the sale or exchange of the share may, to the extent of
the exempt-interest dividends, be disallowed. Furthermore, a portion of any exempt-interest dividend paid by the Fund that
represents income derived from certain revenue or private activity bonds held by the Fund may not retain its tax-exempt status in
the hands of a shareholder who is a “substantial user” of a facility financed by such bonds, or a “related
person” thereof. In addition, the receipt of exempt-interest dividends from the Fund may affect a foreign
corporate shareholder’s federal “branch profits” tax liability and the federal “excess net passive
income” tax liability of a shareholder of a Subchapter S corporation. Shareholders should consult their own tax advisors
as to whether they are (i) “substantial users” with respect to a facility or “related” to such users within
the meaning of the Code or (ii) subject to a federal AMT, the federal “branch profits” tax, or the federal “excess
net passive income” tax.

Qualified
Dividend Income.
“Qualified dividend income” received by an individual is generally taxed at the rates applicable
to long-term capital gain. In order for a dividend received by Fund shareholders to be qualified dividend income, the Fund must meet holding
period and other requirements with respect to the dividend-paying stock in its portfolio and the shareholder must meet holding period
and other requirements with respect to the Fund’s shares. A dividend will not be treated as qualified dividend income (at either
the Fund or shareholder level) (1) if the dividend is received with respect to any share of stock held for fewer than 61 days during the
121-day period beginning at the date which is 60 days before the date on which such share becomes ex-dividend with respect to such dividend
(or, in the case of certain preferred stock, 91 days during the 181-day period beginning 90 days before such date), (2) to the extent
that the recipient is under an obligation (whether pursuant to a short sale or otherwise) to make related payments with respect to positions
in substantially similar or related property, (3) if the recipient elects to have the dividend income treated as investment income for
purposes of the limitation on deductibility of investment interest, or (4) if the dividend is received from a foreign corporation that
is (a) not eligible for the benefits of a comprehensive income tax treaty with the U.S. (with the exception of dividends paid on stock
of such a foreign corporation readily tradable on an established securities market in the U.S.) or (b) treated as a PFIC. Payments in
lieu of dividends, such as payments pursuant to securities lending arrangements, also do not qualify to be treated as qualified dividend
income. In general, distributions of investment income properly reported by the Fund as derived from qualified dividend income will be
treated as qualified dividend income by a shareholder taxed as an individual provided the shareholder meets the holding period and
other requirements described above with respect to the Fund’s shares. In any event, if the aggregate qualified dividends received
by the Fund during any taxable year are 95% or more of its gross income (excluding net long-term capital gain over net short-term capital
loss), then 100% of the Fund’s dividends (other than properly reported capital gain dividends) will be eligible to be treated as
qualified dividend income. For this purpose, the only gain with respect to the sale of stocks and securities included in the term “gross
income” is the excess of net short-term capital gain over net long-term capital loss.

Calvert Mortgage Access Fund 27 SAI dated [______], 2022

 

Dividends-Received Deduction for Corporations. A portion of distributions made by the Fund which are derived from dividends from
U.S. corporations may qualify for the dividends-received deduction (“DRD”) for corporations. The DRD is reduced to the extent
the Fund shares with respect to which the dividends are received are treated as debt-financed under the Code and is eliminated if the
shares are deemed to have been held for less than a minimum period, generally more than 45 days (more than 90 days in the case of certain
preferred stock) during the 91-day period beginning 45 days before the ex-dividend date (during the 181-day period beginning 90 days before
such date in the case of certain preferred stock) or if the recipient is under an obligation (whether pursuant to a short sale or otherwise)
to make related payments with respect to positions in substantially similar or related property. Receipt of certain distributions qualifying
for the DRD may result in reduction of the tax basis of the corporate shareholder’s shares. Payments in lieu of dividends, such
as payments pursuant to securities lending arrangements, also do not qualify for the DRD.

Recognition
of Unrelated Business Taxable Income by Tax-Exempt Shareholders.
Under current law, tax-exempt investors generally will
not recognize unrelated business taxable income (“UBTI”) from distributions from the Fund. Notwithstanding the foregoing,
a tax-exempt shareholder could recognize UBTI if shares in the Fund constitute debt-financed property in the hands of a tax-exempt shareholder
within the meaning of Code section 514(b). In addition, certain types of income received by the Fund from REITs, real estate mortgage
investment conduits (“REMICs”), taxable mortgage pools or other investments may cause the Fund to designate some or all of
its distributions as “excess inclusion income.” To Fund shareholders such excess inclusion income may: (1) constitute income
taxable as UBTI for those shareholders who would otherwise be tax-exempt such as individual retirement accounts, employer sponsored retirement
plans and certain charitable entities; (2) not be offset by otherwise allowable deductions for tax purposes; (3) not be eligible for reduced
U.S. withholding for non-U.S. shareholders even from certain tax treaty countries; and (4) cause the Fund to be subject to tax if certain
“disqualified organizations” as defined by the Code are Fund shareholders.

Sale,
Redemption or Exchange of Fund Shares.
Generally, upon the sale, redemption or (if permitted) exchange of Fund shares,
a shareholder will realize a taxable gain or loss equal to the difference between the amount realized and the shareholder’s
basis in the shares. Such gain or loss will be treated as capital gain or loss if the shares are capital assets in the shareholder’s
hands, and generally will be long-term capital gain or loss if the shares are held for more than one year, and short-term capital gain
or loss if the shares are held for one year or less.

Any loss realized upon the sale or other disposition of Fund
shares with a tax holding period of six months or less will be treated as a long-term capital loss to the extent of any Fund
distributions of capital gain dividends with respect to such shares. In addition, all or a portion of a loss realized on a sale or
other disposition of Fund shares may be disallowed under “wash sale” rules to the extent the shareholder acquired other
shares of the same Fund (whether through the reinvestment of distributions or otherwise) within the period beginning 30 days before
the date of sale or other disposition of the loss shares and ending 30 days after such date. Any disallowed loss will result in an
adjustment to the shareholder’s tax basis in some or all of the other shares acquired. See the prospectus for information
regarding any permitted exchange of Fund shares.

Sales charges paid upon a purchase of shares subject to a front-end
sales charge cannot be taken into account for purposes of determining gain or loss on a redemption or exchange of the shares before the
91st day after their purchase to the extent a sales charge is reduced or eliminated in a subsequent acquisition of Fund shares (or shares
of another fund) on or before January 31 of the following calendar year pursuant to the reinvestment or exchange privilege. Any disregarded
amounts will result in an adjustment to the shareholder’s tax basis in some or all of any other shares acquired.

Applicability
of Medicare Contribution Tax.
The Code imposes a 3.8% Medicare contribution tax on the net investment income of
certain U.S. individuals, estates and trusts. For individuals, the tax is on the lesser of the “net investment income”
and the excess of modified adjusted gross income over $200,000 (or $250,000 if married filing jointly). Net investment income
includes, among other things, interest, dividends, and gross income and capital gains derived from passive activities and trading in
securities or commodities. Net investment income is reduced by deductions “properly allocable” to this income.

Back-Up
Withholding for U.S. Shareholders.
Amounts paid by the Fund to individuals and certain other shareholders who have not
provided the Fund with their correct taxpayer identification number (“TIN”) and certain certifications required by the IRS
as well as shareholders with respect to whom the Fund has received certain information from the IRS or a broker, may be subject to “backup”
withholding of federal income tax arising from the Fund’s taxable dividends and other distributions as well as the proceeds of redemption
transactions (including repurchases and exchanges). An individual’s TIN is generally his or her social security number. Backup withholding
is not an additional tax and any amount withheld may be credited against a shareholder’s U.S. federal income tax liability.

Calvert Mortgage Access Fund 28 SAI dated [______], 2022

 

Taxation
of Foreign Shareholders.
In general, dividends (other than capital gain dividends, interest-related short-term
capital gain dividends and exempt-interest dividends) paid to a shareholder that is not a “U.S. person” within the
meaning of the Code (a “foreign person” or “foreign shareholder”) are subject to withholding of U.S. federal
income tax at a rate of 30% (or lower applicable treaty rate). The withholding tax does not apply to regular dividends paid to a
foreign person who provides an IRS Form W-8ECI, certifying that the dividends are effectively connected with the foreign
person’s conduct of a trade or business within the United States. Instead, the effectively connected dividends will be subject
to regular U.S. income tax as if the foreign person were a U.S. shareholder. A non-U.S. corporation receiving effectively connected
dividends may also be subject to an additional “branch profits tax” imposed at a rate of 30% (or lower treaty rate). A
foreign person who fails to provide an IRS Form W-8BEN, IRS Form W-8BEN-E, or other applicable form may be subject to backup
withholding at the appropriate rate. A foreign shareholder would generally be exempt from U.S. federal income tax, including
withholding tax, on gains realized on the sale of shares of the Fund, capital gain dividends, short-term capital gain dividends,
interest-related dividends, exempt-interest dividends and amounts retained by the Fund that are reported as undistributed capital
gains.

Properly reported dividends are generally exempt from U.S. federal withholding
tax where they (i) are paid in respect of the Fund’s “qualified net interest income” (generally, the Fund’s U.S.
source interest income, other than certain contingent interest and interest from obligations of a corporation or partnership in which
the Fund is at least a 10% shareholder, reduced by expenses that are allocable to such income) or (ii) are paid in respect of the Fund’s
“qualified short-term capital gains” (generally, the excess of the Fund’s net short-term capital gain over the Fund’s
net long-term capital loss for such taxable year). However, depending on its circumstances, the Fund may report all, some or none of its
potentially eligible dividends as such qualified net interest income or as qualified short-term capital gains and/or treat such dividends,
in whole or in part, as ineligible for this exemption from withholding. In order to qualify for this exemption from withholding, a non-U.S.
shareholder would need to comply with applicable certification requirements relating to its non-U.S. status (including, in general, furnishing
an IRS Form W-8BEN, IRS Form W-8BEN-E, or substitute Form). In the case of shares held through an intermediary, the intermediary could
withhold even if the Fund designates the payment as qualified net interest income or qualified short-term capital gain. Non-U.S. shareholders
should contact their intermediaries with respect to the application of these rules to their accounts.

Distributions that the Fund reports as “short-term capital gain
dividends” or “long-term capital gain dividends” will not be treated as such to a recipient foreign shareholder if the
distribution is attributable to gain from the sale or exchange of U.S. real property or an interest in a U.S. real property holding corporation
and the Fund’s direct or indirect interests in U.S. real property exceeded certain levels. Instead, if the foreign shareholder has
not owned more than 5% of the outstanding shares of the Fund at any time during the one year period ending on the date of distribution,
such distributions will be subject to 30% (or lower applicable treaty rate) withholding by the Fund and will be treated as ordinary dividends
to the foreign shareholder; if the foreign shareholder owned more than 5% of the outstanding shares of the Fund at any time during the
one year period ending on the date of the distribution, such distribution will be treated as real property gain subject to 21% withholding
tax and could subject the foreign shareholder to U.S. filing requirements. The rules described in this paragraph, other than the withholding
rules, will apply notwithstanding the Fund’s participation or a foreign shareholder’s participation in a wash sale transaction
or the payment of a substitute dividend.

Additionally, if the Fund’s direct or indirect interests in U.S.
real property were to exceed certain levels, a foreign shareholder realizing gains upon redemption from the Fund could be subject to the
21% withholding tax and U.S. filing requirements unless the foreign person had not held more than 5% of the Fund’s outstanding shares
at any time during the one year period ending on the date of the redemption.

The same rules apply with respect to distributions to a foreign shareholder
from the Fund and redemptions of a foreign shareholder’s interest in the Fund attributable to a REIT’s distribution to the
Fund of gain from the sale or exchange of U.S. real property or an interest in a U.S. real property holding corporation, if the Fund’s
direct or indirect interests in U.S. real property were to exceed certain levels.

Provided that 50% or more of the value of the Fund’s stock is
held by U.S. shareholders, distributions of U.S. real property interests (including securities in a U.S. real property holding corporation,
unless such corporation is regularly traded on an established securities market and the Fund has held 5% or less of the outstanding shares
of the corporation during the five-year period ending on the date of distribution), in redemption of a foreign shareholder’s shares
of the Fund will cause the Fund to recognize gain. If the Fund is required to recognize gain, the amount of gain recognized will be equal
to the fair market value of such interests over the Fund’s adjusted basis to the extent of the greatest foreign ownership percentage
of the Fund during the five-year period ending on the date of redemption.

In the case of foreign non-corporate shareholders, the Fund may be required
to backup withhold U.S. federal income tax on distributions that are otherwise exempt from withholding tax unless such shareholders furnish
the Fund with proper notification of their foreign status.

Shares of the Fund held by a non-U.S. shareholder at death will be considered
situated within the United States and subject to the U.S. estate tax.

Calvert Mortgage Access Fund 29 SAI dated [______], 2022

Compliance
with FATCA.
A 30% withholding tax is imposed on U.S.-source dividends, interest and other income items, including those
paid by the Fund, paid to (i) foreign financial institutions including non-U.S. investment funds unless they agree to collect and disclose
to the IRS information regarding their direct and indirect U.S. account holders and (ii) certain other foreign entities, unless they certify
certain information regarding their direct and indirect U.S. owners. If a payment by the Fund is subject to withholding under FATCA, the
Fund is required to withhold even if such payment would otherwise be exempt from withholding under the rules applicable to foreign shareholders
described above (e.g., dividends attributable to qualified net interest income and dividends attributable to tax-exempt interest income).
The IRS and the Department of Treasury have issued proposed regulations providing that these withholding rules will not be applicable
to the gross proceeds of share redemptions or capital gain dividends the Funds pays. To avoid withholding, foreign financial institutions
will need to either enter into agreements with the IRS that state that they will provide the IRS information, including the names, addresses
and taxpayer identification numbers of direct and indirect U.S. account holders, comply with due diligence procedures with respect to
the identification of U.S. accounts, report to the IRS certain information with respect to U.S. accounts maintained, agree to withhold
tax on certain payments made to non-compliant foreign financial institutions or to account holders who fail to provide the required information,
and determine certain other information as to their account holders or, in the event that an applicable intergovernmental agreement and
implementing legislation are adopted, agree to provide certain information to other revenue authorities for transmittal to the IRS. Other
foreign entities will need to either provide the name, address, and taxpayer identification number of each substantial U.S. owner or certifications
of no substantial U.S. ownership unless certain exceptions apply or agree to provide certain information to other revenue authorities
for transmittal to the IRS. Non-U.S. shareholders should consult their own tax advisors regarding the possible implications of these requirements
on their investment in the Fund.

Requirements
of Form 8886.
Under Treasury Regulations, if a shareholder realizes a loss on disposition of the Fund’s shares
of at least $2 million in any single taxable year or $4 million in any combination of taxable years for an individual shareholder or at
least $10 million in any single taxable year or $20 million in any combination of taxable years for a corporate shareholder, the shareholder
must file with the IRS a disclosure statement on Form 8886. Direct shareholders of portfolio securities are in many cases excepted from
this reporting requirement, but under current guidance, shareholders of a RIC are not excepted. The fact that a loss is reportable under
these regulations does not affect the legal determination of whether the taxpayer’s treatment of the loss is proper. Shareholders
should consult their tax advisors to determine the applicability of these regulations in light of their individual circumstances. Under
certain circumstances, certain tax-exempt entities and their managers may be subject to excise tax if they are parties to certain reportable
transactions.

Tax Treatment
of Variable Annuity/Variable Life Insurance Funding Vehicles.
Special rules apply to insurance company separate accounts
and the Funds (the “Variable Funds”) in which such insurance company separate accounts invest. For federal income tax purposes,
the insurance company separate accounts that invest in a Variable Fund will be treated as receiving the income from the Variable Fund’s
distributions to such accounts, and holders of variable annuity contracts or variable life insurance policies (together, “Variable
Contracts”) generally will not be taxed currently on income or gains realized with respect to such contracts, provided that certain
diversification and “investor control” requirements are met. In order for owners of Variable Contracts to receive such favorable
tax treatment, diversification requirements in Section 817(h) of the Code (“Section 817(h)”) must be satisfied. To determine
whether such diversification requirements are satisfied, an insurance company that offers Variable Contracts generally may “look
through” to the assets of a RIC in which it owns shares (the “Underlying Fund”) if, among other requirements, (1) all
the shares of the Underlying Fund are held by segregated asset accounts of insurance companies and (2) public access to such shares is
only available through the purchase of a variable contract, in each case subject to certain limited exceptions. This provision permits
a segregated asset account to invest all of its assets in shares of a single Underlying Fund without being considered nondiversified,
provided that the Underlying Fund meets the Section 817(h) diversification requirements. This “look through” treatment typically
increases the diversification of the account, because a portion of each of the assets of the Underlying Fund is considered to be held
by the segregated asset account. Because each Variable Fund expects that this look-through rule will apply in determining whether the
Section 817(h) diversification requirements are satisfied with respect to the variable contracts invested in the insurance company separate
accounts that own shares in the Underlying Fund, each Variable Fund intends to comply with the Section 817(h) diversification requirements.
If a Variable Fund failed to qualify as a RIC, the insurance company separate accounts investing in the Variable Fund would no longer
be permitted to look through to the Variable Fund’s investments and, thus, would likely fail to satisfy the Section 817(h) diversification
requirements.

A Variable Fund can generally satisfy the Section 817(h) diversification
requirements in one of two ways. First, the requirements will be satisfied if each Variable Fund invests not more than 55 percent of the
total value of its assets in the securities of a single issuer; not more than 70 percent of the value of its total assets in the securities
of any two issuers; not more than 80 percent of the value of its total assets in the securities of any three issuers; and not more than
90 percent of the value of its total assets in the securities of any four issuers. Alternatively, the diversification requirements will
be satisfied with respect to Variable Fund shares owned by insurance companies as investments for variable contracts if (i) no more than
55 percent of the value of the Variable Fund’s total assets consists of cash, cash items

Calvert Mortgage Access Fund 30 SAI dated [______], 2022

(including receivables), U.S. Government securities, and securities
of other RICs, and (ii) the Variable Fund satisfies the additional diversification requirements for qualification as a RIC under Subchapter
M of the Code discussed above. For purposes of the Section 817(h) diversification rule, all securities of the same issuer are considered
a single investment. In the case of government securities, each United States government agency or instrumentality is generally treated
as a separate issuer. In addition, to the extent any security is guaranteed or insured by the U.S. or an instrumentality of the U.S.,
it will be treated as having been issued by the U.S. or the instrumentality, as applicable.

A Variable Fund will be considered to be in compliance with the Section
817(h) diversification requirements if it is adequately diversified on the last day of each calendar quarter. A Variable Fund that meets
the diversification requirements as of the close of a calendar quarter will not be considered nondiversified in a subsequent quarter because
of a discrepancy between the value of its assets and the diversification requirements unless the discrepancy exists immediately after
the acquisition of any asset and is attributable, in whole or in part, to such acquisition.

If the segregated asset account investing in the Variable Fund is not
adequately diversified at the required time and the correction procedure described below is not available, a Variable Contract based on
the account during the specified time will not be treated as an annuity or life insurance contract within the meaning of the Code and
all income accrued on the Variable Contract for the current and all prior taxable years will be subject to current federal taxation at
ordinary income rates to the holders of such contracts. The Variable Contract will also remain subject to current taxation for all subsequent
tax periods regardless of whether the Fund or separate account becomes adequately diversified in future periods.

In certain circumstances, an inadvertent failure to satisfy the Section
817(h) diversification requirements can be corrected, but generally will require the payment of a penalty to the IRS. The amount of such
penalty will be based on the tax the contract holders would have incurred if they were treated as receiving the income on the contract
for the period during which the diversification requirements were not satisfied. Any such failure also could result in adverse tax consequences
for the insurance company issuing the contracts.

In addition to the Section 817(h) diversification requirements, “investor
control” limitations also are imposed on owners of Variable Contracts. The IRS has issued rulings addressing the circumstances in
which a Variable Contract holder’s control of the investments of the insurance company separate account may cause the holder, rather
than the insurance company, to be treated as the owner of the assets held by the separate account. If the holder is considered the owner
of the securities underlying the separate account, income, and gains produced by those securities would be included currently in the holder’s
gross income. In determining whether an impermissible level of investor control is present, one factor the IRS considers is whether a
Variable Fund’s investment strategies are sufficiently broad to prevent a Variable Contract holder from being deemed to be making
particular investment decisions through its investment in the separate account. For this purpose, current IRS guidance indicates that
typical fund investment strategies, even those with a specific sector or geographical focus, are generally considered sufficiently broad.
Most, although not necessarily all, of the Variable Funds have objectives and strategies that are not materially narrower than the investment
strategies held not to constitute an impermissible level of investor control in recent IRS rulings (such as large company stocks, international
stocks, small company stocks, mortgage-backed securities, money market securities, telecommunications stocks, and financial services stocks).

The above discussion addresses only one of several factors that the
IRS considers in determining whether a Variable Contract holder has an impermissible level of investor control over a separate account.
Variable Contract holders should consult with their own tax advisors, as well as the prospectus relating to their particular Variable
Contract, for more information concerning this investor control issue.

In the event that there is a legislative change or the IRS or Treasury
Department issues rulings, regulations, or other guidance, there can be no assurance that a Variable Fund will be able to operate as currently
described, or that a Variable Fund will not have to change its investment objective or investment policies. While a Variable Fund’s
investment objective is fundamental and may be changed only by a vote of a majority of its outstanding shares, the investment policies
of the Variable Funds may be modified as necessary to prevent any prospective rulings, regulations, or legislative change from causing
Variable Contract owners to be considered the owners of the shares of a Variable Fund.

For a discussion of the tax consequences to owners of Variable Contracts
of Variable Fund distributions to insurance company separate accounts, please see the prospectus provided by the insurance company for
your Variable Contract. Because of the unique tax status of Variable Contracts, you also should consult your tax advisor regarding the
tax consequences of owning Variable Contracts under the federal, state, and local tax rules that apply to you.

Other
Taxes.
Dividends, distributions and redemption proceeds may also be subject to additional state, local and foreign taxes
depending on each shareholder’s particular situation.

Changes in
Taxation.
The taxation of the Fund and shareholders may be adversely affected by future legislation, Treasury Regulations,
IRS revenue procedures and/or guidance issued by the IRS.

Calvert Mortgage Access Fund 31 SAI dated [______], 2022

 

PORTFOLIO SECURITIES TRANSACTIONS

Decisions concerning the execution of portfolio security transactions,
including the selection of the market and the broker-dealer firm, or other financial intermediary (each an “intermediary”),
are made by the investment adviser. The Fund is responsible for the expenses associated with its portfolio transactions. The investment
adviser is also responsible for the execution of transactions for all other accounts managed by it. The investment adviser places the
portfolio security transactions for execution with one or more intermediaries. The investment adviser uses its best efforts to obtain
execution of portfolio security transactions at prices that in the investment adviser’s judgment are advantageous to the client
and at a reasonably competitive spread or (when a disclosed commission is being charged) at reasonably competitive commission rates. In
seeking such execution, the investment adviser will use its best judgment in evaluating the terms of a transaction, and will give consideration
to various relevant factors, which may include, without limitation, the full range and quality of the intermediary’s services, responsiveness
of the intermediary to the investment adviser, the size and type of the transaction, the nature and character of the market for the security,
the confidentiality, speed and certainty of effective execution required for the transaction, the general execution and operational capabilities
of the intermediary, the reputation, reliability, experience and financial condition of the intermediary, the value and quality of the
services rendered by the intermediary in this and other transactions, and the amount of the spread or commission, if any. In addition,
the investment adviser may consider the receipt of Research Services (as defined below), provided it does not compromise the investment
adviser’s obligation to seek best overall execution for the Fund and is otherwise in compliance with applicable law. The investment
adviser may engage in portfolio transactions with an intermediary that sells shares of Calvert funds, provided such transactions are not
directed to that intermediary as compensation for the promotion or sale of such shares.

As described in the Prospectus, following the closing of the Transaction
on March 1, 2021, the investment adviser became an “affiliated person,” as defined in the 1940 Act, of Morgan Stanley and
its affiliates, including certain intermediaries (as previously defined). As a result, the investment adviser is subject to certain restrictions
regarding transactions with Morgan Stanley-affiliated intermediaries, as set forth in the 1940 Act. Under certain circumstances, such
restrictions may limit the investment adviser’s ability to place portfolio transactions on behalf of the Fund at the desired
time or price. Any transaction the investment adviser enters into with a Morgan Stanley-affiliated intermediary on behalf of the Fund
will be done in compliance with applicable laws, rules, and regulations; will be subject to any restrictions contained in the Fund’s
investment advisory agreement; will be subject to the investment adviser’s duty to seek best execution; and, will comply with any
applicable policies and procedures of the investment adviser, as described below.

Subject to the overriding objective of obtaining the best execution
of orders and applicable rules and regulations, as described above, the Fund may use an affiliated intermediary, including a Morgan
Stanley-affiliated intermediary, to effect Fund portfolio transactions, including transactions in futures contracts and options on futures
contracts, under procedures adopted by the Board. In order to use such affiliated intermediaries, the Fund’s Board must approve
and periodically review procedures reasonably designed to ensure that commission rates and other remuneration paid to the affiliated intermediaries
are fair and reasonable in comparison to those of other intermediaries for comparable transactions involving similar securities being
purchased or sold during a comparable time period.

Pursuant to an order issued by the SEC, the Fund is permitted
to engage in principal transactions in money market instruments, subject to certain conditions, with Morgan Stanley & Co. LLC, a broker-dealer
affiliated with Morgan Stanley. Since March 1, 2021, the Fund did not effect any principal transactions with any broker-dealer affiliated
with Morgan Stanley.

Transactions on stock exchanges and other agency transactions involve
the payment of negotiated brokerage commissions. Such commissions vary among different broker-dealer firms, and a particular broker-dealer
may charge different commissions according to such factors as the difficulty and size of the transaction and the volume of business done
with such broker-dealer. Transactions in foreign securities often involve the payment of brokerage commissions, which may be higher than
those in the United States. There is generally no stated commission in the case of securities traded in the over-the-counter markets including
transactions in fixed-income securities which are generally purchased and sold on a net basis (i.e., without commission) through intermediaries
and banks acting for their own account rather than as brokers. Such intermediaries attempt to profit from such transactions by buying
at the bid price and selling at the higher asked price of the market for such obligations, and the difference between the bid and asked
price is customarily referred to as the spread. Fixed-income transactions may also be transacted directly with the issuer of the obligations.
In an underwritten offering the price paid often includes a disclosed fixed commission or discount retained by the underwriter or dealer.
Although spreads or commissions paid on portfolio security transactions will, in the judgment of the investment adviser, be reasonable
in relation to the value of the services provided, commissions exceeding those which another firm might charge may be paid to intermediaries
who were selected to execute transactions on behalf of the investment adviser’s clients in part for providing brokerage and research
services to the investment adviser as permitted by applicable law.

Calvert Mortgage Access Fund 32 SAI dated [______], 2022

Pursuant to the safe harbor provided in Section 28(e) of the Securities
Exchange Act of 1934, as amended (“Section 28(e)”) and to the extent permitted by other applicable law, a broker or dealer
who executes a portfolio transaction may receive a commission that is in excess of the amount of commission another broker or dealer would
have charged for effecting that transaction if the investment adviser determines in good faith that such compensation was reasonable in
relation to the value of the brokerage and research services provided. This determination may be made on the basis of either that particular
transaction or on the basis of the overall responsibility which the investment adviser and its affiliates have for accounts over which
they exercise investment discretion. “Research Services” as used herein includes any and all brokerage and research services
to the extent permitted by Section 28(e) and other applicable law. Generally, Research Services may include, but are not limited to, such
matters as research, analytical and quotation services, data, information and other services products and materials which assist the investment
adviser in the performance of its investment responsibilities. More specifically, Research Services may include general economic, political,
business and market information, industry and company reviews, evaluations of securities and portfolio strategies and transactions, technical
analysis of various aspects of the securities markets, recommendations as to the purchase and sale of securities and other portfolio transactions,
certain financial, industry and trade publications, certain news and information services, and certain research oriented computer software,
data bases and services. Any particular Research Service obtained through a broker-dealer may be used by the investment adviser in connection
with client accounts other than those accounts which pay commissions to such broker-dealer, to the extent permitted by applicable law.
Any such Research Service may be broadly useful and of value to the investment adviser in rendering investment advisory services to all
or a significant portion of its clients, or may be relevant and useful for the management of only one client’s account or of a few
clients’ accounts, or may be useful for the management of merely a segment of certain clients’ accounts, regardless of whether
any such account or accounts paid commissions to the broker-dealer through which such Research Service was obtained. The investment adviser
evaluates the nature and quality of the various Research Services obtained through broker-dealer firms and, to the extent permitted by
applicable law, may attempt to allocate sufficient portfolio security transactions to such firms to ensure the continued receipt of Research
Services which the investment adviser believes are useful or of value to it in rendering investment advisory services to its clients.
The investment adviser may also receive brokerage and Research Services from underwriters and dealers in fixed-price offerings, when permitted
under applicable law.

Research Services provided by (and produced by) broker-dealers that
execute portfolio transactions or from affiliates of executing broker-dealers are referred to as “Proprietary Research.” Except
for trades executed in jurisdictions where such consideration is not permissible, the investment adviser may and does consider the receipt
of Proprietary Research Services as a factor in selecting broker dealers to execute client portfolio transactions, provided it does not
compromise the investment adviser’s obligation to seek best overall execution. In jurisdictions where permissible, the investment
adviser also may consider the receipt of Research Services under so called “client commission arrangements” or “commission
sharing arrangements” (both referred to as “CCAs”) as a factor in selecting broker dealers to execute transactions,
provided it does not compromise the investment adviser’s obligation to seek best overall execution. Under a CCA arrangement, the
investment adviser may cause client accounts to effect transactions through a broker-dealer and request that the broker-dealer allocate
a portion of the commissions paid on those transactions to a pool of commission credits that are paid to other firms that provide Research
Services to the investment adviser. Under a CCA, the broker-dealer that provides the Research Services need not execute the trade. Participating
in CCAs may enable the investment adviser to consolidate payments for research using accumulated client commission credits from transactions
executed through a particular broker-dealer to periodically pay for Research Services obtained from and provided by other firms, including
other broker-dealers that supply Research Services. The investment adviser believes that CCAs offer the potential to optimize the execution
of trades and the acquisition of a variety of high quality Research Services that the investment adviser might not be provided access
to absent CCAs. The investment adviser may enter into CCA arrangements with a number of broker-dealers and other firms, including certain
affiliates of the investment adviser. The investment adviser will only enter into and utilize CCAs to the extent permitted by Section
28(e) and other applicable law.

The EU’s Markets in Financial Instruments Directive II (“MiFID II”), which became effective January 3, 2018, requires
investment advisers regulated under MiFID II to pay for research services separately from trade execution services, either through their
own resources or a research payment account funded by a specific charge to a client. Following its withdrawal from the EU, the United
Kingdom adopted many of the provisions of MiFID II, and investment managers in the United Kingdom are required to comply with certain
MiFID II equivalent requirements in accordance with rules and guidance issued by the Financial Conduct Authority.

Although the Adviser is not directly subject to the provisions of MiFID II, certain of its affiliated advisers are subject to MiFID II
or equivalent requirements under the law of the United Kingdom, such as Morgan Stanley Investment Management Limited and Eaton Vance Advisers
International Ltd (collectively, the “Affiliated Advisers”); accordingly, as applicable, the Adviser makes a reasonable valuation
and allocation of the cost of research services as between MiFID II client accounts and other accounts that are able to participate in
CSAs, and the Affiliated Adviser will pay for research services received with respect to MiFID II client accounts from its own resources.

The investment companies sponsored by the investment adviser or
certain of its affiliates also may allocate brokerage commissions to acquire information relating to the performance, fees and
expenses of such companies and other investment companies, which information is used by the members of the Board of such companies
to fulfill their responsibility to oversee the quality of the services provided to various
entities, including the investment adviser, to such companies. Such companies may also pay cash for such information.

Calvert Mortgage Access Fund 33 SAI dated [______], 2022

Securities considered as investments for the Fund may also be appropriate
for other investment accounts managed by the investment adviser or certain of its affiliates. Whenever decisions are made to buy or sell
securities by the Fund and one or more of such other accounts simultaneously, the investment adviser will allocate the security transactions
(including “new” issues) in a manner which it believes to be equitable under the circumstances. As a result of such allocations,
there may be instances where the Fund will not participate in a transaction that is allocated among other accounts. If an aggregated order
cannot be filled completely, allocations will generally be made on a pro rata basis. An order may not be allocated on a pro rata basis
where, for example: (i) consideration is given to portfolio managers who have been instrumental in developing or negotiating a particular
investment; (ii) consideration is given to an account with specialized investment policies that coincide with the particulars of a specific
investment; (iii) pro rata allocation would result in odd-lot or de minimis amounts being allocated to a portfolio or other client; or
(iv) where the investment adviser reasonably determines that departure from a pro rata allocation is advisable. While these aggregation
and allocation policies could have a detrimental effect on the price or amount of the securities available to the Fund from time to time,
it is the opinion of the members of the Board that the benefits from the investment adviser organization outweigh any disadvantage that
may arise from exposure to simultaneous transactions.

POTENTIAL CONFLICTS OF INTEREST

As a diversified global financial services firm, Morgan Stanley engages
in a broad spectrum of activities, including financial advisory services, investment management activities, lending, commercial banking,
sponsoring and managing private investment funds, engaging in broker-dealer transactions and principal securities, commodities and foreign
exchange transactions, research publication and other activities. In the ordinary course of its business, Morgan Stanley is a full-service
investment banking and financial services firm and therefore engages in activities where Morgan Stanley’s interests or the interests
of its clients may conflict with the interests of a Fund or Portfolio, if applicable, (collectively for the purposes of this section,
“Fund” or “Funds”). Morgan Stanley advises clients and sponsors, manages or advises other investment funds and
investment programs, accounts and businesses (collectively, together with the Morgan Stanley funds, any new or successor funds, programs,
accounts or businesses, (other than funds, programs, accounts or businesses sponsored, managed, or advised by former direct or indirect
subsidiaries of Eaton Vance Corp. (“Eaton Vance Investment Accounts”)), the “MS Investment Accounts,” and, together
with the Eaton Vance Investment Accounts, the ‘‘Affiliated Investment Accounts’’) with a wide variety of investment
objectives that in some instances may overlap or conflict with a Fund’s investment objectives and present conflicts of interest.
In addition, Morgan Stanley or the investment adviser may also from time to time create new or successor Affiliated Investment Accounts
that may compete with a Fund and present similar conflicts of interest. The discussion below enumerates certain actual, apparent and potential
conflicts of interest. There is no assurance that conflicts of interest will be resolved in favor of Fund shareholders and, in fact, they
may not be. Conflicts of interest not described below may also exist. The discussions below with respect to actual, apparent and potential
conflicts of interest also may be applicable to or arise from the MS Investment Accounts whether or not specifically identified.

Material
Non-public and Other Information.
It is expected that confidential or material non-public information regarding an investment
or potential investment opportunity may become available to the investment adviser. If such information becomes available, the investment
adviser may be precluded (including by applicable law or internal policies or procedures) from pursuing an investment or disposition opportunity
with respect to such investment or investment opportunity.

The investment adviser may also from time to time be subject to contractual
‘‘stand-still’’ obligations and/or confidentiality obligations that may restrict its ability to trade in certain
investments on a Fund’s behalf. In addition, the investment adviser may be precluded from disclosing such information to an investment
team, even in circumstances in which the information would be beneficial if disclosed. Therefore, the investment team may not be provided
access to material non-public information in the possession of Morgan Stanley that might be relevant to an investment decision to be made
on behalf of a Fund, and the investment team may initiate a transaction or sell an investment that, if such information had been known
to it, may not have been undertaken. In addition, certain members of the investment team may be recused from certain investment-related
discussions so that such members do not receive information that would limit their ability to perform functions of their employment with
the investment adviser or its affiliates unrelated to that of a Fund. Furthermore, access to certain parts of Morgan Stanley may be subject
to third party confidentiality obligations and to information barriers established by Morgan Stanley in order to manage potential conflicts
of interest and regulatory restrictions, including without limitation joint transaction restrictions pursuant to the 1940 Act. Accordingly,
the investment adviser’s ability to source investments from other business units within Morgan Stanley may be limited and there
can be no assurance that the investment adviser will be able to source any investments from any one or more parts of the Morgan Stanley
network.

Calvert Mortgage Access Fund 34 SAI dated [______], 2022

The investment adviser may restrict its investment decisions and activities
on behalf of the Funds in various circumstances, including because of applicable regulatory requirements or information held by the investment
adviser or Morgan Stanley. The investment adviser might not engage in transactions or other activities for, or enforce certain rights
in favor of, a Fund due to Morgan Stanley’s activities outside the Funds. In instances where trading of an investment is restricted,
the investment adviser may not be able to purchase or sell such investment on behalf of a Fund, resulting in the Fund’s inability
to participate in certain desirable transactions. This inability to buy or sell an investment could have an adverse effect on a Fund’s
portfolio due to, among other things, changes in an investment’s value during the period its trading is restricted. Also, in situations
where the investment adviser is required to aggregate its positions with those of other Morgan Stanley business units for position limit
calculations, the investment adviser may have to refrain from making investments due to the positions held by other Morgan Stanley business
units or their clients. There may be other situations where the investment adviser refrains from making an investment due to additional
disclosure obligations, regulatory requirements, policies, and reputational risk, or the investment adviser may limit purchases or sales
of securities in respect of which Morgan Stanley is engaged in an underwriting or other distribution capacity.

Morgan Stanley has established certain information barriers and other
policies to address the sharing of information between different businesses within Morgan Stanley. As a result of information barriers,
the investment adviser generally will not have access, or will have limited access, to certain information and personnel in other areas
of Morgan Stanley relating to business transactions for clients (including transactions in investing, banking, prime brokerage and certain
other areas), and generally will not manage the Funds with the benefit of the information held by such other areas. Morgan Stanley, due
to its access to and knowledge of funds, markets and securities based on its prime brokerage and other businesses, may make decisions
based on information or take (or refrain from taking) actions with respect to interests in investments of the kind held (directly or indirectly)
by the Funds in a manner that may be adverse to the Funds, and will not have any obligation or other duty to share information with the
investment adviser.

In limited circumstances, however, including for purposes of managing
business and reputational risk, and subject to policies and procedures and any applicable regulations, Morgan Stanley personnel, including
personnel of the investment adviser, on one side of an information barrier may have access to information and personnel on the other side
of the information barrier through “wall crossings.” The investment adviser faces conflicts of interest in determining whether
to engage in such wall crossings. Information obtained in connection with such wall crossings may limit or restrict the ability of the
investment adviser to engage in or otherwise effect transactions on behalf of the Funds (including purchasing or selling securities that
the investment adviser may otherwise have purchased or sold for a Fund in the absence of a wall crossing). In managing conflicts of interest
that arise because of the foregoing, the investment adviser generally will be subject to fiduciary requirements. The investment adviser
may also implement internal information barriers or ethical walls, and the conflicts described herein with respect to information barriers
and otherwise with respect to Morgan Stanley and the investment adviser will also apply internally within the investment adviser. As a
result, a Fund may not be permitted to transact in (e.g., dispose of a security in whole or in part) during periods when it otherwise
would have been able to do so, which could adversely affect a Fund. Other investors in the security that are not subject to such restrictions
may be able to transact in the security during such periods. There may also be circumstances in which, as a result of information held
by certain portfolio management teams in the investment adviser, the investment adviser limits an activity or transaction for a Fund,
including if the Fund is managed by a portfolio management team other than the team holding such information.

Investments
by Morgan Stanley and its Affiliated Investment Accounts.
In serving in multiple capacities to Affiliated Investment Accounts,
Morgan Stanley, including the investment adviser and its investment teams, may have obligations to other clients or investors in Affiliated
Investment Accounts, the fulfillment of which may not be in the best interests of a Fund or its shareholders. A Fund’s investment
objectives may overlap with the investment objectives of certain Affiliated Investment Accounts. As a result, the members of an investment
team may face conflicts in the allocation of investment opportunities among a Fund and other investment funds, programs, accounts and
businesses advised by or affiliated with the investment adviser. Certain Affiliated Investment Accounts may provide for higher management
or incentive fees or greater expense reimbursements or overhead allocations, all of which may contribute to this conflict of interest
and create an incentive for the investment adviser to favor such other accounts.

Morgan Stanley currently invests and plans to continue to invest on
its own behalf and on behalf of its Affiliated Investment Accounts in a wide variety of investment opportunities globally. Morgan Stanley
and its Affiliated Investment Accounts, to the extent consistent with applicable law and policies and procedures, will be permitted to
invest in investment opportunities without making such opportunities available to a Fund beforehand. Subject to the foregoing, Morgan
Stanley may offer investments that fall into the investment objectives of an Affiliated Investment Account to such account or make such
investment on its own behalf, even though such investment also falls within a Fund’s investment objectives. A Fund may invest in
opportunities that Morgan Stanley and/or one or more Affiliated Investment Accounts has declined, and vice versa. All of the foregoing
may reduce the number of investment opportunities available to a Fund and may create conflicts of interest in allocating investment opportunities.
Investors should note that the conflicts inherent in making such allocation decisions may not always be resolved to a Fund’s
advantage. There can be no assurance that a Fund will have an opportunity to participate in certain opportunities that fall within their
investment objectives.

Calvert Mortgage Access Fund 35 SAI dated [______], 2022

To seek to reduce potential conflicts of interest and to attempt to
allocate such investment opportunities in a fair and equitable manner, the investment adviser has implemented allocation policies and
procedures. These policies and procedures are intended to give all clients of the investment adviser, including the Funds, fair access
to investment opportunities consistent with the requirements of organizational documents, investment strategies, applicable laws and regulations,
and the fiduciary duties of the investment adviser. Each client of the investment adviser that is subject to the allocation policies and
procedures, including each Fund, is assigned an investment team and portfolio manager(s) by the investment adviser. The investment team
and portfolio managers review investment opportunities and will decide with respect to the allocation of each opportunity considering
various factors and in accordance with the allocation policies and procedures. The allocation policies and procedures are subject to change.
Investors should note that the conflicts inherent in making such allocation decisions may not always be resolved to the advantage of a
Fund.

It is possible that Morgan Stanley or an Affiliated Investment Account,
including another Eaton Vance fund, will invest in or advise a company that is or becomes a competitor of a company of which a Fund holds
an investment. Such investment could create a conflict between the Fund, on the one hand, and Morgan Stanley or the Affiliated Investment
Account, on the other hand. In such a situation, Morgan Stanley may also have a conflict in the allocation of its own resources to the
portfolio investment. Furthermore, certain Affiliated Investment Accounts will be focused primarily on investing in other funds which
may have strategies that overlap and/or directly conflict and compete with a Fund.

In addition, certain investment professionals who are involved in a
Fund’s activities remain responsible for the investment activities of other Affiliated Investment Accounts managed by the investment
adviser and its affiliates, and they will devote time to the management of such investments and other newly created Affiliated Investment
Accounts (whether in the form of funds, separate accounts or other vehicles), as well as their own investments. In addition, in connection
with the management of investments for other Affiliated Investment Accounts, members of Morgan Stanley and its affiliates may serve on
the boards of directors of or advise companies which may compete with a Fund’s portfolio investments. Moreover, these Affiliated
Investment Accounts managed by Morgan Stanley and its affiliates may pursue investment opportunities that may also be suitable for a Fund.

It should be noted that Morgan Stanley may, directly or indirectly,
make large investments in certain of its Affiliated Investment Accounts, and accordingly Morgan Stanley’s investment in a Fund may
not be a determining factor in the outcome of any of the foregoing conflicts. Nothing herein restricts or in any way limits the activities
of Morgan Stanley, including its ability to buy or sell interests in, or provide financing to, equity and/or debt instruments, funds or
portfolio companies, for its own accounts or for the accounts of Affiliated Investment Accounts or other investment funds or clients in
accordance with applicable law.

Different clients of the investment adviser, including a Fund, may invest
in different classes of securities of the same issuer, depending on the respective clients’ investment objectives and policies.
As a result, the investment adviser and its affiliates, at times, will seek to satisfy fiduciary obligations to certain clients owning
one class of securities of a particular issuer by pursuing or enforcing rights on behalf of those clients with respect to such class of
securities, and those activities may have an adverse effect on another client which owns a different class of securities of such issuer.
For example, if one client holds debt securities of an issuer and another client holds equity securities of the same issuer, if the issuer
experiences financial or operational challenges, the investment adviser and its affiliates may seek a liquidation of the issuer on behalf
of the client that holds the debt securities, whereas the client holding the equity securities may benefit from a reorganization of the
issuer. Thus, in such situations, the actions taken by the investment adviser or its affiliates on behalf of one client can negatively
impact securities held by another client. These conflicts also exist as between the investment adviser’s clients, including the
Funds, and the Affiliated Investment Accounts managed by Morgan Stanley.

The investment adviser and its affiliates may give advice and recommend
securities to other clients which may differ from advice given to, or securities recommended or bought for, a Fund even though such other
clients’ investment objectives may be similar to those of the Fund.

The investment adviser and its affiliates manage long and short portfolios.
The simultaneous management of long and short portfolios creates conflicts of interest in portfolio management and trading in that opposite
directional positions may be taken in client accounts, including client accounts managed by the same investment team, and creates risks
such as: (i) the risk that short sale activity could adversely affect the market value of long positions in one or more portfolios (and
vice versa) and (ii) the risks associated with the trading desk receiving opposing orders in the same security simultaneously. The investment
adviser and its affiliates have adopted policies and procedures that are reasonably designed to mitigate these conflicts. In certain circumstances,
the investment adviser invests on behalf of itself in securities and other instruments that would be appropriate for, held by, or may
fall within the investment guidelines of its clients, including a Fund. At times, the investment adviser may give advice or take action
for its own accounts that differs from, conflicts with, or is adverse to advice given or action taken for any client.

Calvert Mortgage Access Fund 36 SAI dated [______], 2022

From time to time, conflicts also arise due to the fact that certain
securities or instruments may be held in some client accounts, including a Fund, but not in others, or that client accounts may have different
levels of holdings in certain securities or instruments. In addition, due to differences in the investment strategies or restrictions
among client accounts, the investment adviser may take action with respect to one account that differs from the action taken with respect
to another account. In some cases, a client account may compensate the investment adviser based on the performance of the securities held
by that account. The existence of such a performance based fee may create additional conflicts of interest for the investment adviser
in the allocation of management time, resources and investment opportunities. The investment adviser has adopted several policies and
procedures designed to address these potential conflicts including a code of ethics and policies that govern the investment adviser’s
trading practices, including, among other things, the aggregation and allocation of trades among clients, brokerage allocations, cross
trades and best execution.

In addition, at times an investment adviser investment team will give
advice or take action with respect to the investments of one or more clients that is not given or taken with respect to other clients
with similar investment programs, objectives, and strategies. Accordingly, clients with similar strategies will not always hold the same
securities or instruments or achieve the same performance. The investment adviser’s investment teams also advise clients with conflicting
programs, objectives or strategies. These conflicts also exist as between the investment adviser’s clients, including the Funds,
and the Affiliated Investment Accounts managed by Morgan Stanley.

The investment adviser maintains separate trading desks by investment
team and generally based on asset class, including two trading desks trading equity securities. These trading desks operate independently
of one another. The two equity trading desks do not share information. The separate equity trading desks may result in one desk competing
against the other desk when implementing buy and sell transactions, possibly causing certain accounts to pay more or receive less for
a security than other accounts. In addition, Morgan Stanley and its affiliates maintain separate trading desks that operate independently
of each other and do not share trading information with the investment adviser. These trading desks may compete against the investment
adviser trading desks when implementing buy and sell transactions, possibly causing certain Affiliated Investment Accounts to pay more
or receive less for a security than other Affiliated Investment Accounts.

Investments
by Separate Investment Departments.
The entities and individuals that provide investment-related services for the Fund and
certain other Eaton Vance Investment Accounts (the “Eaton Vance Investment Department”) may be different from the entities
and individuals that provide investment-related services to MS Investment Accounts (the “MS Investment Department and, together
with the Eaton Vance Investment Department, the ”Investment Departments“). Although Morgan Stanley has implemented information
barriers between the Investment Departments in accordance with internal policies and procedures, each Investment Department may engage
in discussions and share information and resources with the other Investment Department on certain investment-related matters. The sharing
of information and resources between the Investment Departments is designed to further increase the knowledge and effectiveness of each
Investment Department. Because each Investment Department generally makes investment decisions and executes trades independently of the
other, the quality and price of execution, and the performance of investments and accounts, can be expected to vary. In addition, each
Investment Department may use different trading systems and technology and may employ differing investment and trading strategies. As
a result, a MS Investment Account could trade in advance of the Fund (and vice versa), might complete trades more quickly and efficiently
than the Fund, and/or achieve different execution than the Fund on the same or similar investments made contemporaneously, even when the
Investment Departments shared research and viewpoints that led to that investment decision. Any sharing of information or resources between
the Investment Department servicing the Fund and the MS Investment Department may result, from time to time, in the Fund simultaneously
or contemporaneously seeking to engage in the same or similar transactions as an account serviced by the other Investment Department and
for which there are limited buyers or sellers on specific securities, which could result in less favorable execution for the Fund than
such account. The Eaton Vance Investment Department will not knowingly or intentionally cause the Fund to engage in a cross trade with
an account serviced by the MS Investment Department, however, subject to applicable law and internal policies and procedures, the Fund
may conduct cross trades with other accounts serviced by the Eaton Vance Investment Department. Although the Eaton Vance Investment Department
may aggregate the Fund’s trades with trades of other accounts serviced by the Eaton Vance Investment Department, subject to applicable
law and internal policies and procedures, there will be no aggregation or coordination of trades with accounts serviced by the MS Investment
Department, even when both Investment Departments are seeking to acquire or dispose of the same investments contemporaneously.

Payments
to Broker-Dealers and Other Financial Intermediaries.
The investment adviser and/or EVD may pay compensation, out of their
own funds and not as an expense of the Funds, to certain financial intermediaries (which may include affiliates of the investment adviser
and EVD), including recordkeepers and administrators of various deferred compensation plans, in connection with the sale, distribution,
marketing and retention of shares of the Funds and/or shareholder servicing. For example, the investment adviser or EVD may pay additional
compensation to a financial intermediary for, among other things, promoting the sale and distribution of Fund shares, providing access
to various programs, mutual fund platforms or preferred or recommended mutual fund lists that may be offered by a financial

Calvert Mortgage Access Fund 37 SAI dated [______], 2022

intermediary, granting EVD access to a financial intermediary’s
financial advisors and consultants, providing assistance in the ongoing education and training of a financial intermediary’s financial
personnel, furnishing marketing support, maintaining share balances and/or for sub-accounting, recordkeeping, administrative, shareholder
or transaction processing services. Such payments are in addition to any distribution fees, shareholder servicing fees and/or transfer
agency fees that may be payable by the Funds. The additional payments may be based on various factors, including level of sales (based
on gross or net sales or some specified minimum sales or some other similar criteria related to sales of the Funds and/or some or all
other Eaton Vance funds), amount of assets invested by the financial intermediary’s customers (which could include current or aged
assets of the Funds and/or some or all other Eaton Vance funds), a Fund’s advisory fee, some other agreed upon amount or other measures
as determined from time to time by the investment adviser and/or EVD. The amount of these payments may be different for different financial
intermediaries.

The prospect of receiving, or the receipt of, additional compensation,
as described above, by financial intermediaries may provide such financial intermediaries and their financial advisors and other salespersons
with an incentive to favor sales of shares of the Funds over other investment options with respect to which these financial intermediaries
do not receive additional compensation (or receive lower levels of additional compensation). These payment arrangements, however, will
not change the price that an investor pays for shares of the Funds or the amount that the Funds receive to invest on behalf of an investor.
Investors may wish to take such payment arrangements into account when considering and evaluating any recommendations relating to Fund
shares and should review carefully any disclosures provided by financial intermediaries as to their compensation. In addition, in certain
circumstances, the investment adviser may restrict, limit or reduce the amount of a Fund’s investment, or restrict the type of governance
or voting rights it acquires or exercises, where the Fund (potentially together with Morgan Stanley) exceeds a certain ownership interest,
or possesses certain degrees of voting or control or has other interests.

Morgan Stanley
Trading and Principal Investing Activities.
Notwithstanding anything to the contrary herein, Morgan Stanley will generally
conduct its sales and trading businesses, publish research and analysis, and render investment advice without regard for a Fund’s
holdings, although these activities could have an adverse impact on the value of one or more of the Fund’s investments, or could
cause Morgan Stanley to have an interest in one or more portfolio investments that is different from, and potentially adverse to that
of a Fund. Furthermore, from time to time, the investment adviser or its affiliates may invest “seed” capital in a Fund, typically
to enable the Fund to commence investment operations and/or achieve sufficient scale. The investment adviser and its affiliates may hedge
such seed capital exposure by investing in derivatives or other instruments expected to produce offsetting exposure. Such hedging transactions,
if any, would occur outside of a Fund.

Morgan Stanley’s sales and trading, financing and principal investing
businesses (whether or not specifically identified as such, and including Morgan Stanley’s trading and principal investing businesses)
will not be required to offer any investment opportunities to a Fund. These businesses may encompass, among other things, principal trading
activities as well as principal investing.

Morgan Stanley’s sales and trading, financing and principal investing
businesses have acquired or invested in, and in the future may acquire or invest in, minority and/or majority control positions in equity
or debt instruments of diverse public and/or private companies. Such activities may put Morgan Stanley in a position to exercise contractual,
voting or creditor rights, or management or other control with respect to securities or loans of portfolio investments or other issuers,
and in these instances Morgan Stanley may, in its discretion and subject to applicable law, act to protect its own interests or interests
of clients, and not a Fund’s interests.

Subject to the limitations of applicable law, a Fund may purchase from
or sell assets to, or make investments in, companies in which Morgan Stanley has or may acquire an interest, including as an owner, creditor
or counterparty.

Morgan Stanley’s
Investment Banking and Other Commercial Activities.
Morgan Stanley advises clients on a variety of mergers, acquisitions, restructuring,
bankruptcy and financing transactions. Morgan Stanley may act as an advisor to clients, including other investment funds that may compete
with a Fund and with respect to investments that a Fund may hold. Morgan Stanley may give advice and take action with respect to any of
its clients or proprietary accounts that may differ from the advice given, or may involve an action of a different timing or nature than
the action taken, by a Fund. Morgan Stanley may give advice and provide recommendations to persons competing with a Fund and/or any of
a Fund’s investments that are contrary to the Fund’s best interests and/or the best interests of any of its investments.

Morgan Stanley could be engaged in financial advising, whether on the
buy-side or sell-side, or in financing or lending assignments that could result in Morgan Stanley’s determining in its discretion
or being required to act exclusively on behalf of one or more third parties, which could limit a Fund’s ability to transact with
respect to one or more existing or potential investments. Morgan Stanley may have relationships with third-party funds, companies or investors
who may have invested in or may look to invest in portfolio companies, and there could be conflicts between a Fund’s best interests,
on the one hand, and the interests of a Morgan Stanley client or counterparty, on the other hand.

Calvert Mortgage Access Fund 38 SAI dated [______], 2022

To the extent that Morgan Stanley advises creditor or debtor companies
in the financial restructuring of companies either prior to or after filing for protection under Chapter 11 of the U.S. Bankruptcy Code
or similar laws in other jurisdictions, the investment adviser’s flexibility in making investments in such restructurings on a Fund’s
behalf may be limited. Morgan Stanley could provide investment banking services to competitors of portfolio companies, as well as to private
equity and/or private credit funds; such activities may present Morgan Stanley with a conflict of interest vis-a-vis a Fund’s investment
and may also result in a conflict in respect of the allocation of investment banking resources to portfolio companies.

To the extent permitted by applicable law, Morgan Stanley may provide
a broad range of financial services to companies in which a Fund invests, including strategic and financial advisory services, interim
acquisition financing and other lending and underwriting or placement of securities, and Morgan Stanley generally will be paid fees (that
may include warrants or other securities) for such services. Morgan Stanley will not share any of the foregoing interest, fees and other
compensation received by it (including, for the avoidance of doubt, amounts received by the investment adviser) with a Fund, and any advisory
fees payable will not be reduced thereby.

Morgan Stanley may be engaged to act as a financial advisor to a company
in connection with the sale of such company, or subsidiaries or divisions thereof, may represent potential buyers of businesses through
its mergers and acquisition activities and may provide lending and other related financing services in connection with such transactions.
Morgan Stanley’s compensation for such activities is usually based upon realized consideration and is usually contingent, in substantial
part, upon the closing of the transaction. Under these circumstances, a Fund may be precluded from participating in a transaction with
or relating to the company being sold or participating in any financing activity related to merger or acquisition.

The involvement or presence of Morgan Stanley in the investment banking
and other commercial activities described above (or the financial markets more broadly) may restrict or otherwise limit investment opportunities
that may otherwise be available to the Funds. For example, issuers may hire and compensate Morgan Stanley to provide underwriting, financial
advisory, placement agency, brokerage services or other services and, because of limitations imposed by applicable law and regulation,
a Fund may be prohibited from buying or selling securities issued by those issuers or participating in related transactions or otherwise
limited in its ability to engage in such investments.

The investment adviser believes that the nature and range of clients
to whom Morgan Stanley and its subsidiaries render investment banking and other services is such that it would be inadvisable to exclude
these companies from the Fund’s portfolio.

Morgan Stanley’s
Marketing Activities.
Morgan Stanley is engaged in the business of underwriting, syndicating, brokering, administering, servicing,
arranging and advising on the distribution of a wide variety of securities and other investments in which a Fund may invest. Subject to
the restrictions of the 1940 Act, including Sections 10(f) and 17(e) thereof, a Fund may invest in transactions in which Morgan Stanley
acts as underwriter, placement agent, syndicator, broker, administrative agent, servicer, advisor, arranger or structuring agent and receives
fees or other compensation from the sponsors of such products or securities. Any fees earned by Morgan Stanley in such capacity will not
be shared with the investment adviser or the Funds. Certain conflicts of interest, in addition to the receipt of fees or other compensation,
would be inherent in these transactions. Moreover, the interests of one of Morgan Stanley’s clients with respect to an issuer of
securities in which a Fund has an investment may be adverse to the investment adviser’s or a Fund’s best interests. In conducting
the foregoing activities, Morgan Stanley will be acting for its other clients and will have no obligation to act in the investment adviser’s
or a Fund’s best interests.

Client Relationships.
Morgan Stanley has existing and potential relationships with a significant number of corporations, institutions and individuals.
In providing services to its clients, Morgan Stanley may face conflicts of interest with respect to activities recommended to or performed
for such clients, on the one hand, and a Fund, its shareholders or the entities in which the Fund invests, on the other hand. In addition,
these client relationships may present conflicts of interest in determining whether to offer certain investment opportunities to a Fund.

In acting as principal or in providing advisory and other services to
its other clients, Morgan Stanley may engage in or recommend activities with respect to a particular matter that conflict with or are
different from activities engaged in or recommended by the investment adviser on a Fund’s behalf.

Principal
Investments.
To the extent permitted by applicable law, there may be situations in which a Fund’s interests may conflict
with the interests of one or more general accounts of Morgan Stanley and its affiliates or accounts managed by Morgan Stanley or its affiliates.
This may occur because these accounts hold public and private debt and equity securities of many issuers which may be or become portfolio
companies, or from whom portfolio companies may be acquired.

Calvert Mortgage Access Fund 39 SAI dated [______], 2022

 

Transactions
with Portfolio Companies of Affiliated Investment Accounts.
The companies in which a Fund may invest may be counterparties
to or participants in agreements, transactions or other arrangements with portfolio companies or other entities of portfolio investments
of Affiliated Investment Accounts (for example, a company in which a Fund invests may retain a company in which an Affiliated Investment
Account invests to provide services or may acquire an asset from such company or vice versa). Certain of these agreements, transactions
and arrangements involve fees, servicing payments, rebates and/or other benefits to Morgan Stanley or its affiliates. For example, portfolio
entities may, including at the encouragement of Morgan Stanley, enter into agreements regarding group procurement and/or vendor discounts.
Morgan Stanley and its affiliates may also participate in these agreements and may realize better pricing or discounts as a result of
the participation of portfolio entities. To the extent permitted by applicable law, certain of these agreements may provide for commissions
or similar payments and/or discounts or rebates to be paid to a portfolio entity of an Affiliated Investment Account, and such payments
or discounts or rebates may also be made directly to Morgan Stanley or its affiliates. Under these arrangements, a particular portfolio
company or other entity may benefit to a greater degree than the other participants, and the funds, investment vehicles and accounts (which
may or may not include a Fund) that own an interest in such entity will receive a greater relative benefit from the arrangements than
the Eaton Vance funds, investment vehicles or accounts that do not own an interest therein. Fees and compensation received by portfolio
companies of Affiliated Investment Accounts in relation to the foregoing will not be shared with a Fund or offset advisory fees payable.

Investments
in Portfolio Investments of Other Funds.
To the extent permitted by applicable law, when a Fund invests in certain companies
or other entities, other funds affiliated with the investment adviser may have made or may be making an investment in such companies or
other entities. Other funds that have been or may be managed by the investment adviser may invest in the companies or other entities in
which a Fund has made an investment. Under such circumstances, a Fund and such other funds may have conflicts of interest (e.g., over
the terms, exit strategies and related matters, including the exercise of remedies of their respective investments). If the interests
held by a Fund are different from (or take priority over) those held by such other funds, the investment adviser may be required to make
a selection at the time of conflicts between the interests held by such other funds and the interests held by a Fund.

Allocation
of Expenses
. Expenses may be incurred that are attributable to a Fund and one or more other Affiliated Investment Accounts
(including in connection with issuers in which a Fund and such other Affiliated Investment Accounts have overlapping investments). The
allocation of such expenses among such entities raises potential conflicts of interest. The investment adviser and its affiliates intend
to allocate such common expenses among a Fund and any such other Affiliated Investment Accounts on a pro rata basis or in such other manner
as the investment adviser deems to be fair and equitable or in such other manner as may be required by applicable law.

Temporary
Investments.
To more efficiently invest short-term cash balances held by a Fund, the investment adviser may invest such balances
on an overnight “sweep” basis in shares of one or more money market funds or other short-term vehicles. It is anticipated
that the investment adviser to these money market funds or other short-term vehicles may be the investment adviser (or an affiliate) to
the extent permitted by applicable law, including Rule 12d1-1 under the 1940 Act. The Fund may invest in Eaton Vance Cash Reserves Fund,
LLC (Cash Reserves Fund), an affiliated investment company managed by Eaton Vance, for this purpose. Eaton Vance does not currently receive
a fee for advisory services provided to Cash Reserves Fund.

Transactions
with Affiliates.
The investment adviser and any investment sub-adviser might purchase securities from underwriters or placement
agents in which a Morgan Stanley affiliate is a member of a syndicate or selling group, as a result of which an affiliate might benefit
from the purchase through receipt of a fee or otherwise. Neither the investment adviser nor any investment sub-adviser will purchase securities
on behalf of a Fund from an affiliate that is acting as a manager of a syndicate or selling group. Purchases by the investment adviser
on behalf of a Fund from an affiliate acting as a placement agent must meet the requirements of applicable law. Furthermore, Morgan Stanley
may face conflicts of interest when the Funds use service providers affiliated with Morgan Stanley because Morgan Stanley receives greater
overall fees when they are used.

General Process
for Potential Conflicts.
All of the transactions described above involve the potential for conflicts of interest between the
investment adviser, related persons of the investment adviser and/or their clients. The Advisers Act, the 1940 Act and ERISA impose certain
requirements designed to decrease the possibility of conflicts of interest between an investment adviser and its clients. In some cases,
transactions may be permitted subject to fulfillment of certain conditions. Certain other transactions may be prohibited. In addition,
the investment adviser has instituted policies and procedures designed to prevent conflicts of interest from arising and, when they do
arise, to ensure that it effects transactions for clients in a manner that is consistent with its fiduciary duty to its clients and in
accordance with applicable law. The investment adviser seeks to ensure that potential or actual conflicts of interest are appropriately
resolved taking into consideration the overriding best interests of the client.

Calvert Mortgage Access Fund 40 SAI dated [______], 2022

 

FINANCIAL STATEMENTS

There are no financial statements for the Fund because, prior to the
date of this SAI, the Fund had not commenced operations.

Householding.
Consistent with applicable law, duplicate mailings of shareholder reports and certain other Fund information to shareholders residing
at the same address may be eliminated.

ADDITIONAL INFORMATION ABOUT INVESTMENT STRATEGIES
AND RISKS

Asset Coverage To the extent required by SEC guidance, if a transaction creates a future obligation of the Fund to another party the Fund will: (1) cover the obligation by entering into an offsetting position or transaction; and/or (2) segregate cash and/or liquid securities with a value (together with any collateral posted with respect to the obligation) at least equal to the marked-to-market value of the obligation. Assets used as cover or segregated cannot be sold while the position(s) requiring coverage is open unless replaced with other appropriate assets. The types of transactions that may require asset coverage include (but are not limited to) reverse repurchase agreements, repurchase agreements, short sales, securities lending, forward contracts, certain options, forward commitments, futures contracts, when-issued securities, swap agreements and residual interest bonds.
Asset-Backed Securities (“ABS”)

ABS are collateralized by pools of automobile loans, educational loans,
home equity loans, credit card receivables, equipment or automobile leases, commercial mortgage-backed securities (“MBS”),
utilities receivables, secured or unsecured bonds issued by corporate or sovereign obligors, unsecured loans made to a variety of corporate
commercial and industrial loan customers of one or more lending banks, or a combination of these bonds and loans. ABS are “pass
through” securities, meaning that principal and interest payments made by the borrower on the underlying assets are passed through
to the ABS holder. ABS are issued through special purpose vehicles that are bankruptcy remote from the issuer of the collateral. ABS are
subject to interest rate risk and prepayment risk. Some ABS may receive prepayments that can change their effective maturities. Issuers
of ABS may have limited ability to enforce the security interest in the underlying assets or may have no security in the underlying assets,
and credit enhancements provided to support the securities, if any, may be inadequate to protect investors in the event of default. In
addition, ABS may experience losses on the underlying assets as a result of certain rights provided to consumer debtors under federal
and state law. The value of ABS may be affected by the factors described above and other factors, such as the availability of information
concerning the pool and its structure, the creditworthiness of the servicing agent for the pool, the originator of the underlying assets
or the entities providing credit enhancements and the ability of the servicer to service the underlying collateral. The value of ABS representing
interests in a pool of utilities receivables may be adversely affected by changes in government regulations. While certain ABS may be
insured as to the payment of principal and interest, this insurance does not protect the market value of such obligations or the Fund’s
net asset value. The value of an insured security will be affected by the credit standing of its insurer.

Collateralized debt obligations (“CDOs”) and collateralized
loan obligations (“CLOs”) are types of ABS that are backed solely by a pool of other debt securities. CDOs and CLOs are typically
issued in various classes with varying priorities. The risks of an investment in a CDO or CLO depend largely on the type of the collateral
securities and the class of the CDO or CLO in which the Fund invests. In addition to interest rate, prepayment, default and other risks
of ABS and fixed income securities, in general, CDOs and CLOs are subject to additional risks, including the possibility that distributions
from collateral securities will not be adequate to make interest or other payments, the quality of the collateral may decline in value
or default, the Fund may invest in CDOs or CLOs that are subordinate to other classes, and the complex structure may produce disputes
with the issuer or unexpected investment results. The Fund’s investment in CDOs and CLOs may decrease in market value if they experience
loan defaults or credit impairment, the disappearance of a subordinate tranche or class of debt, or due to market anticipation of defaults
and investor aversion to the securities as a class.

Calvert Mortgage Access Fund 41 SAI dated [______], 2022

 

 

Auction Rate Securities Auction rate securities, such as auction preferred shares of closed-end investment companies, are preferred securities and debt securities with dividends/coupons based on a rate set at auction. The auction is usually held weekly for each series of a security, but may be held less frequently. The auction sets the rate, and securities may be bought and sold at the auction.  Provided that the auction mechanism is successful, auction rate securities normally permit the holder to sell the securities in an auction at par value at specified intervals. The dividend is reset by a “Dutch” auction in which bids are made by broker-dealers and other institutions for a certain amount of securities at a specified minimum yield. The dividend rate set by the auction is the lowest interest or dividend rate that covers all securities offered for sale. While this process is designed to permit auction rate securities to be traded at par value, there is the risk that an auction will fail due to insufficient demand for the securities. Security holders that submit sell orders in a failed auction may not be able to sell any or all of the shares for which they have submitted sell orders. Security holders may sell their shares at the next scheduled auction, subject to the same risk that the subsequent auction will not attract sufficient demand for a successful auction to occur. Broker-dealers may also try to facilitate secondary trading in the auction rate securities, although such secondary trading may be limited and may only be available for shareholders willing to sell at a discount.  Since mid-February 2008, existing markets for certain auction rate securities have become generally illiquid and investors have not been able to sell their securities through the regular auction process. It is uncertain when or whether there will be a revival of investor interest in purchasing securities sold through auctions. There may be limited or no active secondary markets for many auction rate securities. Auction rate securities that do trade in a secondary market may trade at a significant discount from their liquidation preference. There have been a number of governmental investigations and regulatory settlements involving certain broker-dealers with respect to their prior activities involving auction rate securities.
  Valuations of such securities is highly speculative, however, dividends on auction rate preferred securities issued by a closed-end fund may be reported, generally on Form 1099, as exempt from federal income tax to the extent they are attributable to tax-exempt interest income earned by the Fund on the securities and distributed to holders of the preferred securities, provided that the preferred securities are treated as equity securities for federal income tax purposes, and the closed-end fund complies with certain requirements under the Code. Investments in auction rate preferred securities of closed-end funds are subject to limitations on investments in other U.S. registered investment companies, which limitations are prescribed by the 1940 Act.
Average Effective Maturity Average effective maturity is a weighted average of all the maturities of bonds owned by the Fund. Average effective maturity takes into consideration all mortgage payments, puts and adjustable coupons.  In the event the Fund invests in multiple Portfolios, its average weighted maturity is the sum of its allocable share of the average weighted maturity of each of the Portfolios in which it invests, which is determined by multiplying the Portfolio’s average weighted maturity by the Fund’s percentage ownership of that Portfolio.
Borrowing for Investment Purposes Successful use of a borrowing strategy depends on the investment adviser’s ability to predict correctly interest rates and market movements. There is no assurance that a borrowing strategy will be successful. Upon the expiration of the term of the Fund’s existing credit arrangement, the lender may not be willing to extend further credit to the Fund or may be willing to do so at an increased cost to the Fund. If the Fund is not able to extend its credit arrangement, it may be required to liquidate holdings to repay amounts borrowed from the lender. Borrowing to increase investments generally will magnify the effect on the Fund’s net asset value of any increase or decrease in the value of the security purchased with the borrowings. Successful use of a borrowing strategy depends on the investment adviser’s ability to predict correctly interest rates and market movements. There can be no assurance that the use of borrowings will be successful. In connection with its borrowings, the Fund will be required to maintain specified asset coverage with respect to such borrowings by both the 1940 Act and the terms of its credit facility with the lender.  The Fund may be required to dispose of portfolio investments on unfavorable terms if market fluctuations or other factors reduce the required asset coverage to less than the prescribed amount. Borrowings involve additional expense to the Fund.

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Borrowing for Temporary Purposes The Fund may borrow for temporary purposes (such as to satisfy redemption requests, to remain fully invested in advance of the settlement of share purchases, and to settle transactions).  The Fund’s ability to borrow is subject to its terms and conditions of its credit arrangements, which in some cases may limit the Fund’s ability to borrow under the arrangement.  The Fund will be required to maintain a specified level of asset coverage with respect to all borrowings and may be required to sell some of its holdings to reduce debt and restore coverage at times when it may not be advantageous to do so.  The rights of the lender to receive payments of interest and repayments of principal of any borrowings made by the Fund under a credit arrangement are senior to the rights of holders of shares with respect to the payment of dividends or upon liquidation. In the event of a default under a credit arrangement, the lenders may have the right to cause a liquidation of the collateral (i.e., sell Fund assets) and, if any such default is not cured, the lenders may be able to control the liquidation as well.  Credit arrangements are subject to annual renewal, which cannot be assured.  If the Fund does not have the ability to borrow for temporary purposes, it may be required to sell securities at inopportune times to meet short-term liquidity needs.  Because the Fund is a party to a joint credit arrangement, it may be unable to borrow some or all of its requested amounts at any particular time.  Borrowings involve additional expense to the Fund.
Build America Bonds Build America Bonds are taxable municipal obligations issued pursuant to the American Recovery and Reinvestment Act of 2009 (the “Act”) or other legislation providing for the issuance of taxable municipal debt on which the issuer receives federal support. Enacted in February 2009, the Act authorizes state and local governments to issue taxable bonds on which, assuming certain specified conditions are satisfied, issuers may either (i) receive reimbursement from the U.S. Treasury with respect to its interest payments on the bonds (“direct pay” Build America Bonds); or (ii) provide tax credits to investors in the bonds (“tax credit” Build America Bonds). Unlike most other municipal obligations, interest received on Build America Bonds is subject to federal income tax and may be subject to state income tax. Under the terms of the Act, issuers of direct pay Build America Bonds are entitled to receive reimbursement from the U.S. Treasury currently equal to 35% (or 45% in the case of Recovery Zone Economic Development Bonds) of the interest paid. Holders of tax credit Build America Bonds can receive a federal tax credit currently equal to 35% of the coupon interest received. The Fund may invest in “principal only” strips of tax credit Build America Bonds, which entitle the holder to receive par value of such bonds if held to maturity. The Fund does not expect to receive (or pass through to shareholders) tax credits as a result of its investments.  The federal interest subsidy or tax credit continues for the life of the bonds. Build America Bonds are an alternative form of financing to state and local governments whose primary means for accessing the capital markets has been through issuance of tax-free municipal bonds. Build America Bonds can appeal to a broader array of investors than the high income U.S. taxpayers that have traditionally provided the market for municipal bonds. Build America Bonds may provide a lower net cost of funds to issuers. Pursuant to the terms of the Act, the issuance of Build America Bonds ceased on December 31, 2010.  As a result, the availability of such bonds is limited and the market for the bonds and/or their liquidity may be affected.
Call and Put Features on Securities Issuers of securities may reserve the right to call (redeem) the securities. If an issuer redeems a security with a call right during a time of declining interest rates, the holder of the security may not be able to reinvest the proceeds in securities providing the same investment return as provided by the securities redeemed. Some securities may have “put” or “demand” features that allow early redemption by the holder. Longer term fixed-rate securities may give the holder a right to request redemption at certain times (often annually after the lapse of an intermediate term). This “put” or “demand” feature enhances a security’s liquidity by shortening its effective maturity and enables the security to trade at a price equal to or very close to par. If a demand feature terminates prior to being exercised, the holder of the security would be subject to the longer maturity of the security, which could experience substantially more volatility.  Securities with a “put” or “demand” feature are more defensive than conventional long term securities (protecting to some degree against a rise in interest rates) while providing greater opportunity than comparable intermediate term securities, because they can be retained if interest rates decline.

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Collateralized Mortgage Obligations (“CMOs”)   CMOs are backed by a pool of mortgages or mortgage loans.  The key feature of the CMO structure is the prioritization of the cash flows from the pool of mortgages among the several classes, or tranches, of the CMO, thereby creating a series of obligations with varying rates and maturities.  Senior CMO classes will typically have priority over residual CMOs as to the receipt of principal and or interest payments on the underlying mortgages.  CMOs also issue sequential and parallel pay classes, including planned amortization and target amortization classes, and fixed and floating rate CMO tranches.  CMOs issued by U.S. government agencies are backed by agency mortgages, while privately issued CMOs may be backed by either government agency mortgages or private mortgages.  Payments of principal and interest are passed through to each CMO tranche at varying schedules resulting in bonds with different coupons, effective maturities and sensitivities to interest rates. Parallel pay CMOs are structured to provide payments of principal on each payment date to more than one class, concurrently on a proportionate or disproportionate basis.  Sequential pay CMOs generally pay principal to only one class at a time while paying interest to several classes.  CMOs generally are secured by an assignment to a trustee under the indenture pursuant to which the bonds are issued as collateral consisting of a pool of mortgages. Payments with respect to the underlying mortgages generally are made to the trustee under the indenture. CMOs are designed to be retired as the underlying mortgages are repaid. In the event of sufficient early prepayments on such mortgages, the class or series of CMO first to mature generally will be retired prior to maturity. Therefore, although in most cases the issuer of CMOs will not supply additional collateral in the event of such prepayments, there will be sufficient collateral to secure CMOs that remain outstanding. Floating rate CMO tranches carry interest rates that are tied in a fixed relationship to an index subject to an upper limit, or “cap,” and sometimes to a lower limit, or “floor.” CMOs may be less liquid and may exhibit greater price volatility than other types of mortgage- or asset-backed securities.
Commercial Mortgage-Backed Securities (“CMBS”) CMBS include securities that reflect an interest in, and are secured by, mortgage loans on commercial real property, such as hotels, office buildings, retail stores, hospitals and other commercial buildings. CMBS may have a lower repayment uncertainty than other mortgage-related securities because commercial mortgage loans generally prohibit or impose penalties on prepayment of principal.  The risks of investing in CMBS reflect the risks of investing in the real estate securing the underlying mortgage loans, including the effects of local and other economic conditions on real estate markets, the ability of tenants to make loan payment, and the ability of a property to attract and retain tenants. CMBS may be less liquid and may exhibit greater price volatility than other types of mortgage- or asset-backed securities.
Commodity-Related Investments The value of commodities investments will generally be affected by overall market movements and factors specific to a particular industry or commodity, which may include weather, embargoes, tariffs, and health, political, international and regulatory developments. Economic and other events (whether real or perceived) can reduce the demand for commodities, which may reduce market prices and cause the value of Fund shares to fall. The frequency and magnitude of such changes cannot be predicted. Exposure to commodities and commodities markets may subject the Fund to greater volatility than investments in traditional securities. No active trading market may exist for certain commodities investments, which may impair the ability of the Fund to sell or to realize the full value of such investments in the event of the need to liquidate such investments. In addition, adverse market conditions may impair the liquidity of actively traded commodities investments. Certain types of commodities instruments (such as total return swaps and commodity-linked notes) are subject to the risk that the counterparty to the instrument will not perform or will be unable to perform in accordance with the terms of the instrument.  A Fund’s ability to invest in commodity-related investments may be limited by the Code.

Calvert Mortgage Access Fund 44 SAI dated [______], 2022

 

  Certain commodities are subject to limited pricing flexibility because of supply and demand factors. Others are subject to broad price fluctuations as a result of the volatility of the prices for certain raw materials and the instability of supplies of other materials. These additional variables may create additional investment risks and result in greater volatility than investments in traditional securities.  The commodities that underlie commodity futures contracts and commodity swaps may be subject to additional economic and non-economic variables, such as drought, floods, weather, livestock disease, embargoes, tariffs, and international economic, political and regulatory developments.  Unlike the financial futures markets, in the commodity futures markets there are costs of physical storage associated with purchasing the underlying commodity. The price of the commodity futures contract will reflect the storage costs of purchasing the physical commodity, including the time value of money invested in the physical commodity. To the extent that the storage costs for an underlying commodity change while the Fund is invested in futures contracts on that commodity, the value of the futures contract may change proportionately.
  In the commodity futures markets, producers of the underlying commodity may decide to hedge the price risk of selling the commodity by selling futures contracts today to lock in the price of the commodity at delivery tomorrow. In order to induce speculators to purchase the other side of the same futures contract, the commodity producer generally must sell the futures contract at a lower price than the expected future spot price. Conversely, if most hedgers in the futures market are purchasing futures contracts to hedge against a rise in prices, then speculators will only sell the other side of the futures contract at a higher futures price than the expected future spot price of the commodity. The changing nature of the hedgers and speculators in the commodity markets will influence whether futures prices are above or below the expected future spot price, which can have significant implications for the Fund. If the nature of hedgers and speculators in futures markets has shifted when it is time for the Fund to reinvest the proceeds of a maturing contract in a new futures contract, the Fund might reinvest at higher or lower futures prices, or choose to pursue other investments.
Common Stocks Common stock represents an equity ownership interest in the issuing corporation. Holders of common stock generally have voting rights in the issuer and are entitled to receive common stock dividends when, as and if declared by the corporation’s board of directors. Common stock normally occupies the most subordinated position in an issuer’s capital structure. Returns on common stock investments consist of any dividends received plus the amount of appreciation or depreciation in the value of the stock.
  Although common stocks have historically generated higher average returns than fixed-income securities over the long term and particularly during periods of high or rising concerns about inflation, common stocks also have experienced significantly more volatility in returns and may not maintain their real value during inflationary periods. An adverse event, such as an unfavorable earnings report, may depress the value of a particular common stock. Also, the prices of common stocks are sensitive to general movements in the stock market and a drop in the stock market may depress the price of common stocks. Common stock prices fluctuate for many reasons, including changes in investors’ perceptions of the financial condition of an issuer or the general condition of the relevant stock market, or when political or economic events affecting the issuer occur. In addition, common stock prices may be sensitive to rising interest rates as the costs of capital rise and borrowing costs increase.

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Contingent Convertible Securities Contingent convertible securities (sometimes referred to as “CoCos”) are convertible securities with loss absorption characteristics. These securities provide for mandatory conversion into common stock of the issuer under certain circumstances. The mandatory conversion may be automatically triggered, for instance, if a company fails to meet the capital minimum with respect to the security, the company’s regulator makes a determination that the security should convert or the company receives specified levels of extraordinary public support. Since the common stock of the issuer may not pay a dividend, investors in these instruments could experience a reduced income rate, potentially to zero; and conversion would deepen the subordination of the investor, hence worsening standing in a bankruptcy. In addition, some such instruments have a set stock conversion rate that would cause an automatic write-down of capital if the price of the stock is below the conversion price on the conversion date. Under similar circumstances, the liquidation value of certain types of contingent convertible securities may be adjusted downward to below the original par value. The write down of the par value would occur automatically and would not entitle the holders to seek bankruptcy of the company. In certain circumstances, contingent convertible securities may write down to zero and investors could lose the entire value of the investment, even as the issuer remains in business.  CoCos may be subject to redemption at the option of the issuer at a predetermined price.  See also “Hybrid Securities.”
Convertible Securities A convertible security is a bond, debenture, note, preferred security, or other security that entitles the holder to acquire common stock or other equity securities of the same or a different issuer.   A convertible security entitles the holder to receive interest paid or accrued or the dividend paid on such security until the convertible security matures or is redeemed, converted or exchanged. Before conversion, convertible securities have characteristics similar to nonconvertible income securities in that they ordinarily provide a stable stream of income with generally higher yields than those of common stocks of the same or similar issuers, but lower yields than comparable nonconvertible securities. The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security’s investment value. A convertible security ranks senior to common stock in a corporation’s capital structure but is usually subordinated to comparable nonconvertible securities.  Convertible securities may be purchased for their appreciation potential when they yield more than the underlying securities at the time of purchase or when they are considered to present less risk of principal loss than the underlying securities. Generally speaking, the interest or dividend yield of a convertible security is somewhat less than that of a non-convertible security of similar quality issued by the same company.  A convertible security may be subject to redemption at the option of the issuer at a price established in the convertible security’s governing instrument.
  Convertible securities are issued and traded in a number of securities markets. Even in cases where a substantial portion of the convertible securities held by the Fund are denominated in U.S. dollars, the underlying equity securities may be quoted in the currency of the country where the issuer is domiciled. As a result, fluctuations in the exchange rate between the currency in which the debt security is denominated and the currency in which the share price is quoted will affect the value of the convertible security.  With respect to convertible securities denominated in a currency different from that of the underlying equity securities, the conversion price may be based on a fixed exchange rate established at the time the securities are issued, which may increase the effects of currency risk.
  Holders of convertible securities generally have a claim on the assets of the issuer prior to the common stockholders but may be subordinated to other debt securities of the same issuer. Certain convertible debt securities may provide a put option to the holder, which entitles the holder to cause the securities to be redeemed by the issuer at a premium over the stated principal amount of the debt securities under certain circumstances.  Certain convertible securities may include loss absorption characteristics that make the securities more equity-like.  This is particularly true of convertible securities issued by companies in the financial services sector.  See “Contingent Convertible Securities.”

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  Synthetic convertible securities may include either cash-settled convertibles or manufactured convertibles.  Cash-settled convertibles are instruments that are created by the issuer and have the economic characteristics of traditional convertible securities but may not actually permit conversion into the underlying equity securities in all circumstances. As an example, a private company may issue a cash-settled convertible that is convertible into common stock only if the company successfully completes a public offering of its common stock prior to maturity and otherwise pays a cash amount to reflect any equity appreciation. Manufactured convertibles are created by the investment adviser or another party by combining separate securities that possess one of the two principal characteristics of a convertible security, i.e., fixed-income (“fixed-income component”) or a right to acquire equity securities (“convertibility component”). The fixed-income component is achieved by investing in nonconvertible fixed-income securities, such as nonconvertible bonds, preferred securities and money market instruments. The convertibility component is achieved by investing in call options, warrants, or other securities with equity conversion features (“equity features”) granting the holder the right to purchase a specified quantity of the underlying stocks within a specified period of time at a specified price or, in the case of a stock index option, the right to receive a cash payment based on the value of the underlying stock index. A manufactured convertible differs from traditional convertible securities in several respects. Unlike a traditional convertible security, which is a single security that has a unitary market value, a manufactured convertible is comprised of two or more separate securities, each with its own market value. Therefore, the total “market value” of such a manufactured convertible is the sum of the values of its fixed-income component and its convertibility component. More flexibility is possible in the creation of a manufactured convertible than in the purchase of a traditional convertible security. Because many corporations have not issued convertible securities, the investment adviser may combine a fixed-income instrument and an equity feature with respect to the stock of the issuer of the fixed-income instrument to create a synthetic convertible security otherwise unavailable in the market. The investment adviser may also combine a fixed-income instrument of an issuer with an equity feature with respect to the stock of a different issuer when the investment adviser believes such a manufactured convertible would better promote the Fund’s objective than alternative investments. For example, the investment adviser may combine an equity feature with respect to an issuer’s stock with a fixed-income security of a different issuer in the same industry to diversify the Fund’s credit exposure, or with a U.S. Treasury instrument to create a manufactured convertible with a higher credit profile than a traditional convertible security issued by that issuer. A manufactured convertible also is a more flexible investment in that its two components may be purchased separately and, upon purchasing the separate securities, “combined” to create a manufactured convertible. For example, the Fund may purchase a warrant for eventual inclusion in a manufactured convertible while postponing the purchase of a suitable bond to pair with the warrant pending development of more favorable market conditions.  The value of a manufactured convertible may respond to certain market fluctuations differently from a traditional convertible security with similar characteristics. For example, in the event the Fund created a manufactured convertible by combining a short-term U.S. Treasury instrument and a call option on a stock, the manufactured convertible would be expected to outperform a traditional convertible of similar maturity that is convertible
into that stock during periods when Treasury instruments outperform corporate fixed-income securities and underperform during periods when corporate fixed-income securities outperform Treasury instruments.

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Credit Linked Securities See also “Derivative Instruments and Related Risks” herein.  Credit linked securities are issued by a limited purpose trust or other vehicle that, in turn, invests in a derivative instrument or basket of derivative instruments, such as credit default swaps, interest rate swaps, and other securities in order to provide exposure to certain fixed-income markets. Credit linked securities may be used as a cash management tool in order to gain exposure to a certain market and to remain fully invested when more traditional income producing securities are not available.  Like an investment in a bond, investments in credit linked securities represent the right to receive periodic income payments (in the form of distributions) and payment of principal at the end of the term of the security. However, these payments are conditioned on the issuer’s receipt of payments from, and the issuer’s potential obligations to, the counterparties to the derivative instruments and other securities in which the issuer invests. An issuer may sell one or more credit default swaps under which the issuer would receive a stream of payments over the term of the swap agreements provided that no event of default has occurred with respect to the reference instrument (in this case a debt obligation) upon which the swap is based. If a default occurs, the stream of payments may stop and the issuer would be obligated to pay the counterparty the par (or other agreed upon value) of the reference instrument. This, in turn, would reduce the amount of income and principal that the holder of the credit linked security would receive. Credit linked securities generally will be exempt from registration under the 1933 Act. Accordingly, there may be no established trading market for the securities and they may constitute illiquid investments.
Credit Spread Trades A credit spread trade is an investment position relating to a difference in the prices or interest rates of two securities or currencies, where the value of the investment position is determined by movements in the difference between the prices or interest rates, as the case may be, of the respective securities or currencies.
Cybersecurity Risk With the
increased use of technologies by Fund service providers to conduct business, such as the Internet, the Fund is susceptible to
operational, information security and related risks. The Fund relies on communications technology, systems, and networks to engage
with clients, employees, accounts, shareholders, and service providers, and a cyber incident may inhibit the Fund’s ability to
use these technologies. In general, cyber incidents can result from deliberate attacks or unintentional events. Cyber attacks
include, but are not limited to, gaining unauthorized access to digital systems (e.g., through “hacking” or malicious
software coding) for purposes of misappropriating assets or sensitive information, corrupting data, or causing operational
disruption. Cyber attacks may also be carried out in a manner that does not require gaining unauthorized access, such as causing
denial-of-service attacks on websites or via “ransomware” that renders the systems inoperable until appropriate actions are taken. A
denial-of-service attack is an effort to make network services unavailable to intended users, which could cause shareholders to lose
access to their electronic accounts, potentially indefinitely. Employees and service providers also may not be able to access
electronic systems to perform critical duties for the Fund, such as trading, NAV calculation, shareholder accounting or fulfillment
of Fund share purchases and redemptions, during a denial-of-service attack. There is also the possibility for systems failures due
to malfunctions, user error and misconduct by employees and agents, natural disasters, or other foreseeable and unforeseeable
events.
  Because technology is consistently changing, new ways to carry out cyber attacks are always developing. Therefore, there is a chance that some risks have not been identified or prepared for, or that an attack may not be detected, which puts limitations on the Fund’s ability to plan for or respond to a cyber attack. Like other funds and business enterprises, the Fund and its service providers have experienced, and will continue to experience, cyber incidents consistently. In addition to deliberate cyber attacks, unintentional cyber incidents can occur, such as the inadvertent release of confidential information by the Fund or its service providers.

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  The Fund uses third party service providers who are also heavily dependent on computers and technology for their operations. Cybersecurity failures or breaches by the Fund’s investment adviser or administrator and other service providers (including, but not limited to, the custodian or transfer agent), and the issuers of securities in which the Fund invests, may disrupt and otherwise adversely affect their business operations. This may result in financial losses to the Fund, impede Fund trading, interfere with the Fund’s ability to calculate its NAV, limit a shareholder’s ability to purchase or redeem shares of the Fund or cause violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, reimbursement or other compensation costs, litigation costs or additional compliance costs. In addition, substantial costs may be incurred in order to prevent any cyber incidents in the future. While many of the Fund’s service providers have established business continuity plans and risk management systems intended to identify and mitigate cyber attacks, there are inherent limitations in such plans and systems including the possibility that certain risks have not been identified. The Fund cannot control the cybersecurity plans and systems put in place by service providers to the Fund and issuers in which the Fund invests. The Fund and its shareholders could be negatively impacted as a result.
Derivative Instruments and Related Risks Generally, derivatives can be characterized as financial instruments whose performance is derived at least in part from the performance of an underlying reference instrument.  Derivative instruments may be acquired in the United States or abroad and include the various types of exchange-traded and over-the-counter (“OTC”) instruments described herein and other instruments with substantially similar characteristics and risks.  Depending on the type of derivative instrument and the Fund’s investment strategy, a derivative instrument may be based on a security, instrument, index, currency, commodity, economic indicator or event (referred to as “reference instruments”).  Fund obligations created pursuant to derivative instruments may be subject to the requirements described under “Asset Coverage” herein.
  Derivative instruments are subject to a number of risks, including adverse or unexpected movements in the price of the reference instrument, and counterparty, credit, interest rate, leverage, liquidity, market and tax risks.  Use of derivative instruments may cause the realization of higher amounts of short-term capital gains (generally taxed at ordinary income tax rates) than if such instruments had not been used. Success in using derivative instruments to hedge portfolio assets depends on the degree of price correlation between the derivative instruments and the hedged asset.  Derivatives also involve the risk that changes in their value may not correlate perfectly with the assets, rates or indices they are designed to hedge or closely track.  Imperfect correlation may be caused by several factors, including temporary price disparities among the trading markets for the derivative instrument, the reference instrument and the Fund’s assets.  To the extent that a derivative instrument is intended to hedge against an event that does not occur, the Fund may realize losses.
  OTC derivative instruments involve an additional risk in that the issuer or counterparty may fail to perform its contractual obligations. Some derivative instruments are not readily marketable or may become illiquid under adverse market conditions. In addition, during periods of market volatility, an option or commodity exchange or swap execution facility or clearinghouse may suspend or limit trading in an exchange-traded derivative instrument, which may make the contract temporarily illiquid and difficult to price. Commodity exchanges may also establish daily limits on the amount that the price of a futures contract or futures option can vary from the previous day’s settlement price. Once the daily limit is reached, no trades may be made that day at a price beyond the limit. This may prevent the closing out of positions to limit losses.  The ability to terminate OTC derivative instruments may depend on the cooperation of the counterparties to such contracts. For thinly traded derivative instruments, the only source of price quotations may be the selling dealer or counterparty. In addition, certain provisions of the Code limit the use of derivative instruments.   Derivatives permit the Fund to increase or decrease the level of risk, or change the character of the risk, to which its portfolio is exposed in much the same way as the Fund can increase or decrease the level of risk, or change the character of the risk, of its portfolio by making investments in specific securities.  There can be no assurance that the use of derivative instruments will benefit the Fund.

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  The regulation of derivatives has undergone substantial change in recent years. In particular, although many of the provisions of the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) have yet to be fully implemented or are subject to phase-in periods, it is possible that upon implementation these provisions, or any future regulatory or legislative activity, could limit or restrict the ability of a Fund to use derivative instruments, including futures, options on futures and swap agreements as a part of its investment strategy, increase the costs of using these instruments or make them less effective. New position limits imposed on a Fund or its counterparty may also impact the Fund’s ability to efficiently utilize futures, options, and swaps.
  As of October 28, 2020, the SEC has adopted new regulations that may significantly alter a Fund’s regulatory obligations with regard to its derivatives usage. In particular, the new regulations will, upon implementation, eliminate the current asset segregation framework for covering derivatives and certain other financial instruments, impose new responsibilities on the Board and establish new reporting and recordkeeping requirements for a Fund and may, depending on the extent to which a Fund uses derivatives, impose value at risk limitations on a Fund’s use of derivatives, and require the Fund’s Board to adopt a derivative risk management program. The implementation of these requirements may limit the ability of a Fund to use derivative instruments as part of its investment strategy, increase the costs of using these instruments or make them less effective. Limits or restrictions applicable to the counterparties with which a Fund engages in derivative transactions also could prevent the Fund from using these instruments or affect the pricing or other factors relating to these instruments, or may change the availability of certain investments.
  Legislation may be enacted that could negatively affect the assets of the Fund. Legislation or regulation may also change the way in which the Fund itself is regulated. The effects of any new governmental regulation cannot be predicted and there can be no assurance that any new governmental regulation will not adversely affect the Fund’s performance or ability to achieve its investment objective(s).
Derivative-Linked and Commodity-Linked Hybrid Instruments A derivative-linked or commodity-linked hybrid instrument (referred to herein as a “hybrid instrument”) is a type of potentially high-risk derivative that combines a traditional stock, bond, or commodity with an option or forward contract. Generally, the principal amount, amount payable upon maturity or redemption, or interest rate of a hybrid instrument is tied (positively or negatively) to the price of some commodity, currency or securities index or another interest rate or some other economic factor (each a “benchmark”). The interest rate or (unlike most fixed-income securities) the principal amount payable at maturity of a hybrid instrument may be increased or decreased, depending on changes in the value of the benchmark. An example of a hybrid instrument is a bond issued by an oil company that pays a small base level of interest with additional interest that accrues in correlation to the extent to which oil prices exceed a certain predetermined level. Such a hybrid instrument would be a combination of a bond and a call option on oil.
  The risks of investing in hybrid instruments reflect a combination of the risks of investing in securities, options, futures and currencies. An investment in a hybrid instrument may entail significant risks that are not associated with a similar investment in a traditional debt instrument that has a fixed principal amount, is denominated in U.S. dollars or bears interest either at a fixed rate or a floating rate determined by reference to a common, nationally published benchmark. The risks of a particular hybrid instrument will depend upon the terms of the instrument, but may include the possibility of significant changes in the benchmark(s) or the prices of the underlying assets to which the instrument is linked. Such risks generally depend upon factors unrelated to the operations or credit quality of the issuer of the hybrid instrument, which may not be foreseen by the purchaser, such as economic and political events, the supply and demand of the underlying assets and interest rate movements. Hybrid instruments may be highly volatile and their use by the Fund may not be successful.  Hybrid instruments may also carry liquidity risk since the instruments are often “customized” to meet the portfolio needs of a particular investor, and therefore, the number of investors that are willing and able to buy such instruments in the secondary market may be smaller than that for more traditional debt securities.  

Calvert Mortgage Access Fund 50 SAI dated [______], 2022

 

  Hybrid instruments may bear interest or pay preferred dividends at below market (or even relatively nominal) rates. Alternatively, hybrid instruments may bear interest at above market rates but bear an increased risk of principal loss (or gain). The latter scenario may result if “leverage” is used to structure the hybrid instrument. Leverage risk occurs when the hybrid instrument is structured so that a given change in a benchmark or underlying asset is multiplied to produce a greater value change in the hybrid instrument, thereby magnifying the risk of loss as well as the potential for gain.
  Hybrid instruments are potentially more volatile and carry greater market risks than traditional debt instruments. Depending on the structure of the particular hybrid instrument, changes in a benchmark may be magnified by the terms of the hybrid instrument and have an even more dramatic and substantial effect upon the value of the hybrid instrument. Also, the prices of the hybrid instrument and the benchmark or underlying asset may not move in the same direction or at the same time.
  Hybrid instruments can be used as an efficient means of pursuing a variety of investment goals, including currency hedging, duration management, and increased total return and creating exposure to a particular market or segment of that market. The value of a hybrid instrument or its interest rate may be a multiple of a benchmark and, as a result, may be leveraged and move (up or down) more steeply and rapidly than the benchmark. These benchmarks may be sensitive to economic and political events, such as commodity shortages and currency devaluations, which cannot be readily foreseen by the purchaser of a hybrid instrument. Under certain conditions, the redemption value of a hybrid instrument could be zero. The purchase of hybrid instruments also exposes the Fund to the credit risk of the issuer of the hybrids. These risks may cause significant fluctuations in the net asset value of the Fund.
  Certain hybrid instruments may provide exposure to the commodities markets. These are derivative securities with one or more commodity-linked components that have payment features similar to commodity futures contracts, commodity options, or similar instruments. Commodity-linked hybrid instruments may be either equity or debt securities, leveraged or unleveraged, and are considered hybrid instruments because they have both security and commodity-like characteristics. A portion of the value of these instruments may be derived from the value of a commodity, futures contract, index or other economic variable. The Fund will invest only in commodity-linked hybrid instruments that qualify under applicable rules of the CFTC for an exemption from the provisions of the CEA.  Certain issuers of structured products such as hybrid instruments may be deemed to be investment companies as defined in the 1940 Act. As a result, the Fund’s investments in these products may be subject to limits applicable to investments in investment companies and may be subject to restrictions contained in the 1940 Act.
Direct Investments Direct investments include (i) the private purchase from an enterprise of an equity interest in the enterprise in the form of shares of common stock or equity interests in trusts, partnerships, joint ventures or similar enterprises, and (ii) the purchase of such an equity interest in an enterprise from a principal investor in the enterprise. At the time of making a direct investment, the Fund will enter into a shareholder or similar agreement with the enterprise and one or more other holders of equity interests in the enterprise. These agreements may, in appropriate circumstances, provide the ability to appoint a representative to the board of directors or similar body of the enterprise and for eventual disposition of the investment in the enterprise. Such a representative would be expected to monitor the investment and protect the Fund’s rights in the investment and would not be appointed for the purpose of exercising management or control of the enterprise.
Diversified Status With respect to 75% of its total assets, an investment company that is registered with the SEC as a “diversified” fund: (1) may not invest more than 5% of its total assets in the securities of any one issuer (except obligations issued or guaranteed by the U.S. Government, its agencies or instrumentalities and securities of other investment companies); and (2) may not own more than 10% of the outstanding voting securities of any one issuer.

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Duration Duration measures the time-weighted expected cash flows of a fixed-income security, which can determine its sensitivity to changes in the general level of interest rates. Securities with longer durations generally tend to be more sensitive to interest rate changes than securities with shorter durations. A mutual fund with a longer dollar-weighted average duration generally can be expected to be more sensitive to interest rate changes than a fund with a shorter dollar-weighted average duration. Duration differs from maturity in that it considers a security’s coupon payments in addition to the amount of time until the security matures. Various techniques may be used to shorten or lengthen Fund duration. As the value of a security changes over time, so will its duration.  The duration of a Fund that invests in underlying funds is the sum of its allocable share of the duration of each of the underlying funds in which it invests, which is determined by multiplying the underlying fund’s duration by the Fund’s percentage ownership of that underlying fund.
Emerging Market Investments The risks described under “Foreign Investments” herein generally are heightened in connection with investments in emerging markets.  Also, investments in securities of issuers domiciled in countries with emerging capital markets may involve certain additional risks that do not generally apply to investments in securities of issuers in more developed capital markets, such as (i) low or non-existent trading volume, resulting in a lack of liquidity and increased volatility in prices for such securities, as compared to securities of comparable issuers in more developed capital markets; (ii) uncertain national policies and social, political and economic instability, increasing the potential for expropriation of assets, confiscatory taxation, high rates of inflation or unfavorable diplomatic developments; (iii) possible fluctuations in exchange rates, differing legal systems and the existence or possible imposition of exchange controls, custodial restrictions or other foreign or U.S. governmental laws or restrictions applicable to such investments; (iv) governmental actions or  policies that may limit investment opportunities, such as restrictions on investment in, or required divestment of, certain issuers or industries; and (v) the lack or relatively early development of legal structures governing private and foreign investments and private property. Governmental actions may effectively restrict or eliminate the Fund’s ability to purchase or sell investments in emerging market countries, and thus may make them less liquid or more difficult to value, or may force the Fund to sell or otherwise dispose of such investments at inopportune times or prices. Trading practices in emerging markets also may be less developed, resulting in inefficiencies relative to trading in more developed markets, which may result in increased transaction costs.  
  Repatriation of investment income, capital and proceeds of sales by foreign investors may require governmental registration and/or approval in emerging market countries.  There can be no assurance that repatriation of income, gain or initial capital from these countries will occur.  In addition to withholding taxes on investment income, some countries with emerging markets may impose differential capital gains taxes on foreign investors.  
  Political and economic structures in emerging market countries may undergo significant evolution and rapid development, and these countries may lack the social, political and economic stability characteristic of more developed countries. In such a dynamic environment, there can be no assurance that any or all of these capital markets will continue to present viable investment opportunities. In the past, governments of such nations have expropriated substantial amounts of private property, and most claims of the property owners have never been fully settled. There is no assurance that such expropriations will not reoccur. In such an event, it is possible that the entire value of an investment in the affected market could be lost. In addition, unanticipated political or social developments may affect the value of investments in these countries and the availability of additional investments. The small size and inexperience of the securities markets in certain of these countries and the limited volume of trading in securities in these countries may make investments in the countries illiquid and more volatile than investments in developed markets.

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  Also, there may be less publicly available information about issuers in emerging markets than would be available about issuers in more developed capital markets, and such issuers may not be subject to accounting, auditing and financial reporting standards and requirements comparable to those to which U.S. companies are subject. In certain countries with emerging capital markets, reporting standards vary widely. As a result, traditional investment measurements used in the United States, such as price/earnings ratios, may not be applicable. Certain emerging market securities may be held by a limited number of persons. This may adversely affect the timing and pricing of the acquisition or disposal of securities.  The prices at which investments may be acquired may be affected by trading by persons with material non-public information and by securities transactions by brokers in anticipation of transactions in particular securities.
  Practices in relation to settlement of securities transactions in emerging markets involve higher risks than those in developed markets, in part because brokers and counterparties in such markets may be less well capitalized, and custody and registration of assets in some countries may be unreliable. The possibility of fraud, negligence, undue influence being exerted by the issuer or refusal to recognize ownership exists in some emerging markets.  As an alternative to investing directly in emerging markets, exposure may be obtained through derivative investments.
  Additionally, there may be difficulties in obtaining and/or enforcing legal judgements against non-U.S. companies and non-U.S. persons, including company directors or officers, in foreign jurisdictions. Shareholders of emerging market issuers often have limited rights and few practical remedies in jurisdictions located in emerging markets. In addition, due to jurisdictional limitations, U.S. authorities (e.g., the SEC and the U.S. Department of Justice) may be limited in their ability to enforce regulatory or legal obligations in emerging market countries. Such risks vary from jurisdiction to jurisdiction and company to company.
  Investments in China may involve a high risk of currency fluctuations, currency non-convertibility, interest rate fluctuations and higher rates of inflation as a result of internal social unrest or conflicts with other countries. Increasing trade tensions, particularly regarding trading arrangements between the U.S. and China, may result in additional tariffs or other actions that could have an adverse impact on an investment in the China region, including but not limited to restrictions on investments in certain Chinese companies. Accounting, auditing, financial, and other reporting standards, practices and disclosure requirements in China are different, sometimes in fundamental ways, from those in the United States and certain western European countries. For example, there is less regulatory oversight of financial reporting by companies domiciled in China than for companies in the United States.
  The foregoing risks may be even greater in frontier markets. Frontier markets are countries with investable stock markets that are less established than those in the emerging markets. The economies of frontier market countries generally are smaller than those of traditional emerging market countries, and frontier capital markets and legal systems are typically less developed.
Equity Investments Equity investments include common stocks; preferred stocks; depositary receipts; equity interests in trusts, partnerships, joint ventures and other unincorporated entities or enterprises; convertible and contingent convertible preferred stocks; rights and warrants and other securities that are treated as equity for U.S. federal income tax purposes (see “Preferred Stock” and “Hybrid Securities”).  Market conditions may affect certain types of stocks to a greater extent than other types of stocks.
Equity-Linked Securities See also “Derivative Instruments and Related Risks” and “Participation Notes” herein.  Equity-linked securities are privately issued securities whose investment results are designed to correspond generally to the performance of a specified stock index or “basket” of securities, or sometimes a single stock.  These securities are used for many of the same purposes as derivative instruments and share many of the same risks.  Equity-linked securities may be considered illiquid and thus subject to the Fund’s restrictions on investments in illiquid securities.

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Event-Linked Instruments The Fund may obtain event-linked exposure by investing in “event-linked bonds”, “event-linked swaps” or other “event-linked instruments”.  Event-linked instruments are obligations for which the return of capital and dividend/interest payments are contingent on, or formulaically related to, the non-occurrence of a pre-defined “trigger” event. For some event-linked instruments, the trigger event’s magnitude may be based on losses to a company or industry, industry indexes or readings of scientific instruments rather than specified actual losses.  Examples of trigger events include hurricanes, earthquakes, weather-related phenomena, or statistics relating to such events.
  Some event-linked instruments are referred to as “catastrophe bonds.” Catastrophe bonds entitle a Fund to receive principal and interest payments so long as no trigger event occurs of the description and magnitude specified by the instrument. If a trigger event occurs, the Fund may lose a portion of its entire principal invested in the bond.
  Event-linked instruments may be sponsored by government agencies, insurance companies or reinsurers and issued by special purpose corporations or other off-shore or on-shore entities (such special purpose entities are created to accomplish a narrow and well-defined objective, such as the issuance of a note in connection with a specific reinsurance transaction). Typically, event-linked instruments are issued by off-shore entities and may be non-dollar denominated.  As a result, the Fund may be subject to currency risk.
  Often, event-linked instruments provide for extensions of maturity that are mandatory or optional at the discretion of the issuer or sponsor, in order to process and audit loss claims in those cases where a trigger event has, or possibly has, occurred. An extension of maturity may increase the instrument’s volatility and potentially make it more difficult to value.  In addition, pricing of event-linked instruments is subject to the added uncertainty caused by the inability to generally predict whether, when or where a natural disaster or other triggering event will occur.  If a trigger event occurs, the Fund may lose all or a portion of its investment in an event-linked instrument or the notional amount of an event-linked swap. Such losses may be substantial.  Event-linked instruments carry large uncertainties and major risk exposures to adverse conditions.  In addition to the specified trigger events, event-linked instruments also may expose the Fund to issuer, credit, counterparty, restricted securities, liquidity, and valuation risks as well as exposures to specific geographic areas, adverse regulatory or jurisdictional interpretations, and adverse tax consequences.  Event-linked instruments are generally rated below investment grade or the unrated equivalent and have the same or similar risks as high yield debt securities (also known as junk bonds) and are subject to the risk that the Fund may lose some or all of its investment in such instruments if the particular trigger occurs.  Event-linked instruments may be rated by a nationally recognized statistical rating agency, but are often unrated. Frequently, the issuer of an event-linked instrument will use an independent risk model to calculate the probability and economic consequences of a trigger event.
  The Fund may invest in event-linked instruments in one or more of three ways: may purchase event-linked instruments when initially offered; may purchase event-linked instruments in the secondary, over-the-counter market; or may gain indirect exposure to event-linked instruments using derivatives. As the market for event-linked instruments evolves, the Fund may invest in new types of event-linked instruments.  However, there can be no assurance that a liquid market in these instruments will develop. Lack of a liquid market may impose the risk of higher transaction costs and the possibility that the Fund may be forced to liquidate positions when it would not be advantageous to do so.
  Event-linked instruments typically are restricted to qualified institutional buyers and, therefore, are not subject to registration with the SEC or any state securities commission and are not always listed on any national securities exchange. The amount of public information available with respect to event-linked instruments is generally less extensive than that which is available for issuers of registered or exchange listed instruments. There can be no assurance that future regulatory determinations will not adversely affect the overall market for event-linked instruments.

Calvert Mortgage Access Fund 54 SAI dated [______], 2022

 

 

Exchange-Traded Funds (“ETFs”)

ETFs are pooled investment vehicles that trade their shares on stock
exchanges at market prices (rather than net asset value) and are only redeemable from the ETF itself in large increments or in exchange
for baskets of securities. As an exchange traded security, an ETF’s shares are priced continuously and trade throughout the day.
ETFs may track a securities index, a particular market sector, a particular segment of a securities index or market sector (“Passive
ETFs”), or they may be actively managed (“Active ETFs”). An investment in an ETF generally involves the same primary
risks as an investment in a fund that is not exchange-traded that has the same investment objectives, strategies and policies of the ETF,
such as liquidity risk, sector risk and foreign and emerging market risk, as well as risks associated with equity securities, fixed income
securities, real estate investments and commodities, as applicable. In addition, a Passive ETF may fail to accurately track the market
segment or index that underlies its investment objective or may fail to fully replicate its underlying index, in which case the Passive
ETF’s investment strategy may not produce the intended results. The way in which shares of ETFs are traded, purchased and redeemed
involves certain risks. An ETF may trade at a price that is lower than its net asset value. Secondary market trading of an ETF may result
in frequent price fluctuations, which in turn may result in a loss to a Fund. Additionally, there is no guarantee that an active market
for the ETF’s shares will develop or be maintained. An ETF may fail to meet the listing requirements of any applicable exchanges
on which it is listed. Further, trading in an ETF may be halted if the trading in one or more of the securities held by an ETF is halted.
The existence of extreme market volatility or potential lack of an active trading market for an ETF’s shares could result in such
shares trading at a significant premium or discount to their NAV and/or being more volatile than an ETF’s underlying securities.

A Fund will indirectly bear its proportionate share of any management
fees and other operating expenses of an ETF in which it invests. A Fund may pay brokerage commissions in connection with the purchase
and sale of shares of ETFs.

Exchange-Traded Notes (“ETNs”) ETNs are senior, unsecured, unsubordinated debt securities whose returns are linked to the performance of a particular market benchmark or strategy minus applicable fees. ETNs are traded on an exchange during normal trading hours. However, investors can also hold the ETN until maturity. At maturity, the issuer pays to the investor a cash amount equal to the principal amount, subject to the day’s market benchmark or strategy factor.
  ETNs do not make periodic coupon payments or provide principal protection. ETNs are subject to credit risk and the value of the ETN may drop due to a downgrade in the issuer’s credit rating, despite the underlying market benchmark or strategy remaining unchanged. The value of an ETN may also be influenced by time to maturity, level of supply and demand for the ETN, volatility and lack of liquidity in underlying assets, changes in the applicable interest rates, changes in the issuer’s credit rating, and economic, legal, political, or geographic events that affect the referenced underlying asset. When the Fund invests in ETNs it will bear its proportionate share of any fees and expenses borne by the ETN. The Fund’s decision to sell its ETN holdings may be limited by the availability of a secondary market. In addition, although an ETN may be listed on an exchange, the issuer may not be required to maintain the listing and there can be no assurance that a secondary market will exist for an ETN.
  ETNs are subject to tax risk. No assurance can be given that the IRS will accept, or a court will uphold, how the Fund characterizes and treats ETNs for tax purposes. Further, the IRS and Congress are considering proposals that would change the timing and character of income and gains from ETNs.
  An ETN that is tied to a specific market benchmark or strategy may not be able to replicate and maintain exactly the composition and relative weighting of securities, commodities or other components in the applicable market benchmark or strategy. Some ETNs that use leverage can, at times, be relatively illiquid and, thus, they may be difficult to purchase or sell at a fair price. Leveraged ETNs are subject to the same risk as other instruments that use leverage in any form.
  The market value of ETN shares may differ from that of their market benchmark or strategy. This difference in price may be due to the fact that the supply and demand in the market for ETN shares at any point in time is not always identical to the supply and demand in the market for the securities, commodities or other components underlying the market benchmark or strategy that the ETN seeks to track. As a result, there may be times when an ETN share trades at a premium or discount to its market benchmark or strategy.

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Fixed-Income Securities Fixed-income
securities include bonds, preferred, preference and convertible securities, notes, debentures, asset-backed securities (including
those backed by mortgages), loan participations and assignments, equipment lease certificates, equipment trust certificates and
conditional sales contracts. Generally, issuers of fixed-income securities pay investors periodic interest and repay the amount
borrowed either periodically during the life of the security and/or at maturity.  Some fixed-income securities, such as
zero coupon bonds, do not pay current interest, but are purchased at a discount from their face values, and values accumulate over
time to face value at maturity.  The market prices of fixed-income securities fluctuate depending on such factors as
interest rates, credit quality and maturity.  In general, market prices of fixed-income securities decline when interest
rates rise and increase when interest rates fall. Fixed-income securities are subject to risk factors such as sensitivity to
interest rate and real or perceived changes in economic conditions, payment expectations, credit quality, liquidity and
valuation.  Fixed-income securities with longer maturities (for example, over ten years) are more affected by changes in
interest rates and provide less price stability than securities with short-term maturities (for example, one to ten
years). Fixed-income securities bear the risk of principal and interest default by the issuer, which will be greater with
higher yielding, lower grade securities. During an economic downturn, the ability of issuers to service their debt may be
impaired.  The rating assigned to a fixed-income security by a rating agency does not reflect assessment of the volatility
of the security’s market value or of the liquidity of an investment in the securities. Credit ratings are based largely on the
issuer’s historical financial condition and a rating agency’s investment analysis at the time of rating, and the rating
assigned to any particular security is not necessarily a reflection of the issuer’s current financial condition. Credit
quality can change from time to time, and recently issued credit ratings may not fully reflect the actual risks posed by a
particular high yield security. If relevant to the Fund(s) in this SAI, corporate bond ratings are described in an appendix to the
SAI (see the table of contents).  Preferred stock and certain other hybrid securities may pay a fixed-dividend rate, but
may be considered equity securities for purposes of a Fund’s investment restrictions (see “Preferred Stock” and
“Hybrid Securities”).  
  The fixed-income securities market has been and may continue to be negatively affected by the COVID-19 pandemic. As with other serious economic disruptions, governmental authorities and regulators are responding to this crisis with significant fiscal and monetary policy changes, including considerably lowering interest rates, which, in some cases could result in negative interest rates. These actions, including their possible unexpected or sudden reversal or potential ineffectiveness, could further increase volatility in securities and other financial markets and reduce market liquidity. To the extent the Fund has a bank deposit or holds a debt instrument with a negative interest rate to maturity, the Fund would generate a negative return on that investment. Similarly, negative rates on investments by money market funds and similar cash management products could lead to losses on investments, including on investments of the Fund’s uninvested cash.
Foreign Currency Transactions As measured in U.S. dollars, the value of assets denominated in foreign currencies may be affected favorably or unfavorably by changes in foreign currency rates and exchange control regulations. Currency exchange rates can also be affected unpredictably by intervention by U.S. or foreign governments or central banks, or the failure to intervene, or by currency controls or political developments in the United States or abroad.  If the U.S. dollar rises in value relative to a foreign currency, a security denominated in that foreign currency will be worth less in U.S. dollars. If the U.S. dollar decreases in value relative to a foreign currency, a security denominated in that foreign currency will be worth more in U.S. dollars. A devaluation of a currency by a country’s government or banking authority will have a significant impact on the value of any investments denominated in that currency.  Foreign currency exchange transactions may be conducted on a spot (i.e., cash) basis at the spot rate prevailing in the foreign currency exchange market or through entering into derivative currency transactions (see “Forward Foreign Currency Exchange Contracts,” “Option Contracts,” “Futures Contracts” and “Swap Agreements – Currency Swaps” herein).  Currency transactions are subject to the risk of a number of complex political and economic factors applicable to the countries issuing the underlying currencies. Furthermore, unlike trading in most other types of instruments, there is no systematic reporting of last sale information with respect to the foreign currencies underlying the derivative currency transactions. As a result, available information may not be complete. In an over-the-counter trading environment, there are no daily price fluctuation limits.

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Foreign Investments Investing in securities issued by companies whose principal business activities are outside the United States may involve significant risks not present in domestic investments. For example, because foreign companies may not be subject to uniform accounting, auditing and financial reporting standards, practices and requirements and regulatory measures comparable to those applicable to U.S. companies, there may be less publicly available information about a foreign company than about a domestic company. Volume and liquidity in most foreign debt markets is less than in the United States and securities of some foreign companies are less liquid and more volatile than securities of comparable U.S. companies. There is generally less government supervision and regulation of securities exchanges, broker-dealers and listed companies than in the United States. In addition, with respect to certain foreign countries, there is the possibility of nationalization, expropriation or confiscatory taxation, currency blockage, political or social instability, or diplomatic developments, which could affect investments in those countries. If a deterioration occurs in a country’s balance of payments, the country could impose temporary restrictions on foreign capital remittances. The Fund could also be adversely affected by delays in, or a refusal to grant, any required governmental approval for repatriation. Any of these actions could adversely affect securities prices, impair the Fund’s ability to purchase or sell foreign securities, or transfer the Fund’s assets or income back to the United States, or otherwise adversely affect Fund operations. In the event of nationalization, expropriation or confiscation, the Fund could lose its entire investment in that country. The risks posed by such actions with respect to a particular foreign country, its nationals or industries or businesses within the country may be heightened to the extent the Fund invests significantly in the affected country or region or in issuers from the affected country that depend on global markets.
  Other
potential foreign market risks include exchange controls, difficulties in valuing securities, defaults on foreign government
securities, and difficulties of enforcing favorable legal judgments in foreign courts.  Moreover, individual foreign
economies may differ favorably or unfavorably from the U.S. economy in such respects as growth of gross national product,
reinvestment of capital, rate of inflation, capital reinvestment, resource self-sufficiency, and balance of payments position.
Certain economies may rely heavily on particular industries or foreign capital and are more vulnerable to diplomatic developments,
the imposition of economic sanctions against a particular country or countries, changes in international trading patterns, trade
barriers, and other protectionist or retaliatory measures.  Foreign securities markets, while growing in volume and
sophistication, are generally not as developed as those in the United States.  Foreign countries may not have the
infrastructure or resources to respond to natural and other disasters that interfere with economic activities, which may adversely
affect issuers located in such countries. Foreign investment in the securities markets of certain foreign countries is restricted or
controlled to varying degrees. In addition, to the extent that a Fund holds such a security, one or more Fund intermediaries may
decline to process customer orders with respect to such Fund unless and until certain representatives are made by the Fund or the
prohibited holdings are divested. As a result of forced sales of a security, or inability to participate in an investment the
manager otherwise believes is attractive, a Fund may incur losses. The U.S. is also renegotiating many of its global trade
relationships and has imposed or threatened to impose significant import tariffs. These actions could lead to price volatility and
overall declines in U.S. and global investment markets.
  Settlement and clearance procedures in certain foreign markets differ significantly from those in the United States. Payment for securities before delivery may be required and in some countries delayed settlements are customary, which increases the Fund’s risk of loss. The Fund generally holds its foreign securities and related cash in foreign banks and securities depositories. Some foreign banks and securities depositories may be recently organized or new to the foreign custody business. In addition, there may be limited or no regulatory oversight over their operations. Also, the laws of certain countries may put limits on the Fund’s ability to recover its assets if a foreign bank, depository or issuer of a security or any of their agents goes bankrupt.  Certain countries may require withholding on dividends paid on portfolio securities and on realized capital gains.
  In addition, it is often more expensive to buy, sell and hold securities in certain foreign markets than in the United States. Foreign brokerage commissions are generally higher than commissions on securities traded in the United States and may be non-negotiable.  The fees paid to foreign banks and securities depositories generally are higher than those charged by U.S. banks and depositories.  The increased expense of investing in foreign markets reduces the amount earned on investments and typically results in a higher operating expense ratio for the Fund as compared to investment companies that invest only in the United States.

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  Depositary receipts (including American Depositary Receipts (“ADRs”) and Global Depositary Receipts “GDRs”)) are certificates evidencing ownership of shares of a foreign issuer and are alternatives to directly purchasing the underlying foreign securities in their national markets and currencies. However, they continue to be subject to many of the risks associated with investing directly in foreign securities. These risks include the political and economic risks of the underlying issuer’s country, as well as in the case of depositary receipts traded on foreign markets, exchange risk.  Depositary receipts may be sponsored or unsponsored. Unsponsored depositary receipts are established without the participation of the issuer. As a result, available information concerning the issuer of an unsponsored depository receipt may not be as current as for sponsored depositary receipts, and the prices of unsponsored depositary receipts may be more volatile than if such instruments were sponsored by the issuer. Unsponsored depositary receipts may involve higher expenses, may not pass through voting or other shareholder rights and they may be less liquid.
 

Unless otherwise provided in the Prospectus, in determining the domicile
of an issuer, the investment adviser may consider the domicile determination of the Fund’s benchmark index or a leading provider
of global indexes and may take into account such factors as where the company’s securities are listed, and where the company is
legally organized, maintains principal corporate offices and/or conducts its principal operations.

In June 2016, the United Kingdom (“UK”) voted in a referendum
to leave the European Union (“EU”) (“Brexit”). Effective January 31, 2020, the UK ceased to be a member of the
EU and, following a transition period, during which the EU and the UK Government engaged in a series of negotiations regarding the terms
of the UK’s future relationship with the EU, the EU and the UK Government signed an agreement on December 30, 2020 regarding the
economic relationship between the UK and the EU. This agreement became effective on a provisional basis on January 1, 2021 and entered
into full force on May 1, 2021. There remains significant market uncertainty regarding Brexit’s ramifications, and the range and
potential implications of possible political, regulatory, economic, and market outcomes are difficult to predict. Moreover, the uncertainty
about the ramifications of Brexit may cause significant volatility and/or declines in the value of the Euro and the British pound. The
end of the Brexit transition period may cause greater market volatility and illiquidity, currency fluctuations, deterioration in economic
activity, a decrease in business confidence, and an increased likelihood of a recession in the UK. Brexit may create additional substantial
economic stresses for the UK, including price volatility in UK stocks, capital outflows, wider corporate bond spreads due to uncertainty
and declines in business and consumer spending as well as foreign direct investment. Brexit may also adversely affect UK-based financial
firms that have counterparties in the EU or participate in market infrastructure (trading venues, clearing houses, settlement facilities)
based in the EU. These consequences may be exacerbated by the COVID-19 pandemic. Political events, including nationalist unrest in Europe,
uncertainties surrounding the sovereign debt of a number of EU countries and the viability of the EU (or the euro) itself, also may cause
market disruptions. If one or more countries leave the EU or the EU dissolves, the world’s securities markets likely will be significantly
disrupted.

Calvert Mortgage Access Fund 58 SAI dated [______], 2022

 

 

Forward Foreign Currency Exchange Contracts See also “Derivative Instruments and Related Risks” herein.  A forward foreign currency exchange contract involves an obligation to purchase or sell a specific currency at a future date, which may be any fixed number of days from the date of the contract agreed upon by the parties, at a price set at the time of the contract. These contracts may be bought or sold to protect against an adverse change in the relationship between currencies or to increase exposure to a particular foreign currency. Cross-hedging may be done by using forward contracts in one currency (or basket of currencies) to hedge against fluctuations in the value of instruments denominated in a different currency (or the basket of currencies and the underlying currency). Use of a different foreign currency (for hedging or non-hedging purposes) magnifies exposure to foreign currency exchange rate fluctuations. Forward foreign currency exchange contracts are individually negotiated and privately traded so they are dependent upon the creditworthiness of the counterparty. The precise matching of the forward contract amounts and the value of the instruments denominated in the corresponding currencies will not generally be possible because the future value of such securities in foreign currencies will change as a consequence of market movements in the value of those securities between the date on which the contract is entered into and the date it matures. There is additional risk that the use of currency forwards may reduce or preclude the opportunity for gain if the value of the currency should move in the direction opposite to the position taken and that currency forwards may create exposure to currencies in which the Fund’s securities are not denominated. In addition, it may not be possible to hedge against long-term currency changes.
  When a currency is difficult to hedge or to hedge against the U.S. dollar, the Fund may enter into a forward contract to sell a currency whose changes in value are generally considered to be linked to such currency. Currency transactions can result in losses if the currency being hedged fluctuates in value to a degree or in a direction that is not anticipated. In addition, there is the risk that the perceived linkage between various currencies may not be present or may not be present during the particular time the hedge is in place. If the Fund purchases a bond denominated in a foreign currency with a higher interest rate than is available on U.S. bonds of a similar maturity, the additional yield on the foreign bond could be substantially reduced or lost if the Fund were to enter into a direct hedge by selling the foreign currency and purchasing the U.S. dollar.  
  Some of the forward foreign currency exchange contracts may be classified as non-deliverable forwards (“NDFs”). NDFs are cash-settled, forward contracts that may be thinly traded. NDFs are commonly quoted for time periods of one month up to two years, and are normally quoted and settled in U.S. dollars, but may be settled in other currencies. They are often used to gain exposure to or hedge exposure to foreign currencies that are not internationally traded.  NDFs may also be used to gain or hedge exposure to gold.
Forward Rate Agreements See also “Derivative Instruments and Related Risks” herein.  Under a forward rate agreement, the buyer locks in an interest rate at a future settlement date. If the interest rate on the settlement date exceeds the lock rate, the buyer pays the seller the difference between the two rates. If the lock rate exceeds the interest rate on the settlement date, the seller pays the buyer the difference between the two rates. Any such gain received by the Fund would be taxable.  These instruments are traded in the OTC market.

Calvert Mortgage Access Fund 59 SAI dated [______], 2022

 

 

Futures Contracts See also “Derivative Instruments and Related Risks” herein.  Futures contracts are standardized contracts that obligate a purchaser to take delivery, and a seller to make delivery, of a specific amount of the underlying reference instrument at a specified future date at a specified price.  These contracts are traded on exchanges, so that, in most cases, either party can close out its position on the exchange for cash, without delivering the underlying asset.  Upon purchasing or selling a futures contract, a purchaser or seller is required to deposit collateral (initial margin).  Each day thereafter until the futures position is closed, the purchaser or seller will pay additional margin (variation margin) representing any loss experienced as a result of the futures position the prior day or be entitled to a payment representing any profit experienced as a result of the futures position the prior day.  A public market exists in futures contracts covering a number of indexes as well as financial instruments and foreign currencies. It is expected that other futures contracts will be developed and traded in the future.  In computing daily net asset value, the Fund will mark to market its open futures positions. The Fund is also required to deposit and maintain margin with respect to put and call options on futures contracts written by it. Futures contracts are traded on exchanges or boards of trade that are licensed by the CFTC and must be executed through a futures commission merchant or brokerage firm that is a member of the relevant exchange or board.
  Although some futures contracts call for making or taking delivery of the underlying reference instrument, generally these obligations are closed out prior to delivery by offsetting purchases or sales of matching futures contracts (same exchange, underlying security or index, and delivery month). Closing a futures contract sale is effected by purchasing a futures contract for the same aggregate amount of the specific type of financial instrument or commodity with the same delivery date. If an offsetting purchase price is less than the original sale price, the Fund realizes a capital gain, or if it is more, the Fund realizes a capital loss. Conversely, if an offsetting sale price is more than the original purchase price, the Fund realizes a capital gain, or if it is less, the Fund realizes a capital loss.

Calvert Mortgage Access Fund 60 SAI dated [______], 2022

 

 

High Social Impact Investments

High Social Impact Investments are investments that, in the Adviser’s
opinion, offer the opportunity for significant sustainability and social impact. High Social Impact Investments include (i) debt obligations
that offer a below-market interest rate and (ii) equity investments that may not generate a market rate of return.

High Social Impact Investment debt obligations are unrated and of below-investment
grade quality, and involve a greater risk of default and price decline than investment grade investments. High Social Impact Investments
are illiquid, and the Fund may be unable to dispose of them at current carrying values.

Any Fund investment in High Social Impact Investments is fair valued
pursuant to valuation procedures adopted by the Fund’s Board and implemented by the Adviser. See “Valuing Shares” in
this Prospectus. High Social Impact Investments by the Fund may be direct investments in an issuer or investments in an intermediate entity
that then makes High Social Impact Investments, such as Calvert Impact Capital, Inc. (as discussed below).

Pursuant to an exemptive order issued by the SEC, the Fund may invest
in Community Investment Notes (“Notes”) issued by Calvert Impact Capital, Inc. (“CIC”) as part of the Fund’s
High Social Impact Investments. CIC is a nonstock corporation organized under the laws of the State of Maryland and designed to operate
as a non-profit organization within the meaning of the Internal Revenue Code of 1986, as amended. CIC focuses its work on offering investors
the ability to support organizations that strengthen communities and sustain our planet. CIC issues Notes with fixed-rates of interest
to domestic individuals and institutional investors and the proceeds from the Notes primarily are used to provide financing to community
development organizations, projects, funds and other social enterprises across a variety of impact sectors, including community development,
microfinance, affordable housing, small business, renewable energy, environmental sustainability, education, health, and sustainable agriculture
(collectively, the “Participating Borrowers”) with missions that may include addressing climate change, supporting quality
education, promoting financial inclusion, strengthening women’s empowerment, and increasing access to quality affordable housing.
CIC issues Notes with interest rates that currently range from 0%–4% and terms currently ranging from one to 15 years, and in turn
makes loans to Participating Borrowers at rates determined through consideration of the general current market, the Participating Borrower’s
positive social and/or environmental impact and the Participating Borrower’s risk level.

The Adviser has licensed use of the Calvert name to CIC and provides
other types of support. The Adviser’s President and Chief Executive Officer (and the only director/trustee on the Fund Board that
is an “interested person” of the Fund) serves on the CIC Board. In addition, another director/trustee on the Fund Board serves
as a director emeritus on the CIC Board.

Hybrid Securities Hybrid securities generally possess certain characteristics of both equity and debt securities. These securities may at times behave more like equity than debt, or vice versa. Preferred stocks, convertible securities, trust preferred securities and certain debt obligations are types of hybrid securities.  The investment adviser has sole discretion to determine whether an investment has hybrid characteristics and generally will consider the instrument’s preference over the issuer’s common shares, the term of the instrument at the time of issuance and/or the tax character of the instrument’s distributions.  Debt instruments with a preference over common shares and a perpetual term or a term at issuance of thirty years or more generally are considered by the investment adviser to be hybrid securities. Hybrid securities generally do not have voting rights or have limited voting rights.  Because hybrid securities have both debt and equity characteristics, their values vary in response to many factors, including general market and economic conditions, issuer-specific events, changes in interest rates, credit spreads and the credit quality of the issuer, and, for convertible securities, factors affecting the securities into which they convert.  Hybrid securities may be subject to redemption at the option of the issuer at a predetermined price. Hybrid securities may pay a fixed or variable rate of interest or dividends. The prices and yields of nonconvertible hybrid securities generally move with changes in interest rates and the issuer’s credit quality, similar to the factors affecting debt securities. If the issuer of a hybrid security experiences financial difficulties, the value of such security may be adversely affected similar to the issuer’s outstanding common stock or subordinated debt instruments.  Trust preferred securities are issued by a special purpose trust that holds the subordinated debt of a company and, as such, are subject to the risks associated with such debt obligation.  See also “Preferred Stock,” “Convertible Securities” and “Contingent Convertible Securities.”   

Calvert Mortgage Access Fund 61 SAI dated [______], 2022

 

 

Illiquid Investments Certain investments are considered illiquid or restricted due to a limited trading market or legal or contractual restrictions on resale or transfer, or are otherwise illiquid because they cannot be sold or disposed of in seven calendar days or less under then-current market conditions without the sale or disposition significantly changing the market value of the investment.  Such illiquid investments may include commercial paper issued pursuant to Section 4(a)(2) of the 1933 Act and securities eligible for resale pursuant to Rule 144A thereunder. Rule 144A securities may increase the level of portfolio illiquidity if eligible buyers become uninterested in purchasing such securities.
  It may be difficult to sell illiquid investments at a price representing fair value until such time as the investments may be sold publicly. It also may be more difficult to determine the fair value of such investments for purposes of computing the Fund’s net asset value.  Where registration is required, a considerable period of time may elapse between a decision to sell the investments and the time when the Fund would be permitted to sell. Thus, the Fund may not be able to obtain as favorable a price as that prevailing at the time of the decision to sell. The Fund may incur additional expense when disposing of illiquid investments, including all or a portion of the cost to register the investments.  The Fund also may acquire investments through private placements under which it may agree to contractual restrictions on the resale of such investments that are in addition to applicable legal restrictions. Such restrictions might prevent the sale of such investments at a time when such sale would otherwise be desirable.
  At times, a portion of the Fund’s assets may be invested in investments as to which the Fund, by itself or together with other accounts managed by the investment adviser and its affiliates, holds a major portion or all of such investments. Under adverse market or economic conditions or in the event of adverse changes in the financial condition of the issuer, the Fund could find it more difficult to sell such investments when the investment adviser believes it advisable to do so or may be able to sell such investments only at prices lower than if such investments were more widely held.  It may also be more difficult to determine the fair value of such investments for purposes of computing the Fund’s net asset value.  See also “Restricted Securities.”
Index Tracking The Fund’s portfolio will be invested in a manner intended to track the Index as discussed in the Prospectus. To the extent that a Fund has investments in the Special Equities program and/or the High Social Impact Investments program, the Fund may be less able to closely track the Index than if it did not have investments in these programs. Both of these investment programs are of limited size so that the tracking error induced by such investments would be limited.
Indexed Securities See also “Derivative Instruments and Related Risks” herein.  Indexed securities are securities that fluctuate in value with an index. The interest rate or, in some cases, the principal payable at the maturity of an indexed security may change positively or inversely in relation to one or more interest rates, financial indices, securities prices or other financial indicators (“reference prices”). An indexed security may be leveraged to the extent that the magnitude of any change in the interest rate or principal payable on an indexed security is a multiple of the change in the reference price. Thus, indexed securities may decline in value due to adverse market changes in reference prices. Because indexed securities derive their value from another instrument, security or index, they are considered derivative debt securities, and are subject to different combinations of prepayment, extension, interest rate and/or other market risks. Indexed securities may include interest only (“IO”) and principal only (“PO”) securities, floating rate securities linked to the Cost of Funds Index (“COFI floaters”), other “lagging rate” floating securities, floating rate securities that are subject to a maximum interest rate (“capped floaters”), leveraged floating rate securities (“super floaters”), leveraged inverse floating rate securities (“inverse floaters”), dual index floaters, range floaters, index amortizing notes and various currency indexed notes.  Indexed securities may be issued by the U.S. Government or one of its agencies or instrumentalities or, if privately issued, collateralized by mortgages that are insured, guaranteed or otherwise backed by the U.S. Government, its agencies or instrumentalities.

Calvert Mortgage Access Fund 62 SAI dated [______], 2022

 

 

Inflation-Indexed (or Inflation-Linked) Bonds Inflation-indexed bonds are fixed-income securities the principal value of which is periodically adjusted according to the rate of inflation. Inflation-indexed bonds are issued by governments, their agencies or instrumentalities and corporations. Two structures are common: The U.S. Treasury and some other issuers use a structure that accrues inflation into the principal value of the bond. Most other issuers pay out the inflation accruals as part of a semiannual coupon.  The principal amount of an inflation-indexed bond is adjusted in response to changes in the level of inflation.  Repayment of the original bond principal upon maturity (as adjusted for inflation) is guaranteed in the case of U.S. Treasury inflation-indexed bonds, and therefore, the principal amount of such bonds cannot be reduced below par even during a period of deflation.  However, the current market value of these bonds is not guaranteed and will fluctuate, reflecting the risk of changes in their yields.  In certain jurisdictions outside the United States, the repayment of the original bond principal upon the maturity of an inflation-indexed bond is not guaranteed, allowing for the amount of the bond repaid at maturity to be less than par.  The interest rate for inflation-indexed bonds is fixed at issuance as a percentage of this adjustable principal.  Accordingly, the actual interest income may both rise and fall as the principal amount of the bonds adjusts in response to movements in the Consumer Price Index.  
  The value of inflation-indexed bonds is expected to change in response to changes in real interest rates. Real interest rates in turn are tied to the relationship between nominal interest rates and the rate of inflation. Therefore, if inflation were to rise at a faster rate than nominal interest rates, real interest rates might decline, leading to an increase in value of inflation-indexed bonds. In contrast, if nominal interest rates increased at a faster rate than inflation, real interest rates might rise, leading to a decrease in value of inflation-indexed bonds. While these securities are expected to be protected from long-term inflationary trends, short-term increases in inflation may lead to a decline in value. If interest rates rise due to reasons other than inflation (for example, due to changes in currency exchange rates), investors in these securities may not be protected to the extent that the increase is not reflected in the bond’s inflation measure.
Junior Loans Due to their lower place in the borrower’s capital structure and possible unsecured status, certain loans (“Junior Loans”) involve a higher degree of overall risk than Senior Loans (described below) of the same borrower.  Junior Loans may be direct loans or purchased either in the form of an assignment or a loan participation.  Junior Loans are subject to the same general risks inherent in any loan investment (see “Loans” below). Junior Loans include secured and unsecured subordinated loans, as well as second lien loans and subordinated bridge loans. A second lien loan is generally second in line in terms of repayment priority and may have a claim on the same collateral pool as the first lien, or it may be secured by a separate set of assets. Second lien loans generally give investors priority over general unsecured creditors in the event of an asset sale.
  Bridge loans or bridge facilities are short-term loan arrangements (e.g., 12 to 18 months) typically made by a borrower in anticipation of intermediate-term or long-term permanent financing. Most bridge loans are structured as floating-rate debt with step-up provisions under which the interest rate on the bridge loan rises the longer the loan remains outstanding and may be converted into senior exchange notes if the loan has not been prepaid in full on or prior to its maturity date. Bridge loans may be subordinate to other debt and may be secured or unsecured. Bridge loans are generally made with the expectation that the borrower will be able to obtain permanent financing in the near future. Any delay in obtaining permanent financing subjects the bridge loan investor to increased risk. A borrower with an outstanding bridge loan may be unable to locate permanent financing to replace the bridge loan, which may impair the borrower’s perceived creditworthiness. From time to time, the Fund may make a commitment to participate in a bridge loan facility, obligating itself to participate in the facility if it funds. In return for this commitment, the Fund receives a fee.
  For additional disclosure relating to investing in loans (including Junior Loans), see “Loans” below.  

Calvert Mortgage Access Fund 63 SAI dated [______], 2022

 

 

LIBOR Transition and Associated Risk

The London Interbank Offered Rate (‘LIBOR“) is the average
offered rate for various maturities of short-term loans between major international banks who are members of the British Bankers Association.
LIBOR is the most common benchmark interest rate index used to make adjustments to variable-rate loans. It is used throughout global banking
and financial industries to determine interest rates for a variety of financial instruments (such as debt instruments and derivatives)
and borrowing arrangements. In July 2017, the Financial Conduct Authority (the ”FCA“), the United Kingdom financial regulatory
body, announced a desire to phase out the use of LIBOR. The ICE Benchmark Administration Limited, the administrator of LIBOR, is expected
to cease publishing certain LIBOR settings on December 31, 2021, and the remaining LIBOR settings on June 30, 2023. Many market participants
are in the process of transitioning to the use of alternative reference or benchmark rates.

Although the transition process away from LIBOR has become increasingly
well-defined in advance of the anticipated discontinuation, the impact on certain debt securities, derivatives and other financial instruments
that utilize LIBOR remains uncertain. The transition process may involve, among other things, increased volatility or illiquidity in markets
for instruments that currently rely on LIBOR. The transition may also result in a change in (i) the value of certain instruments held
by the Fund, (ii) the cost of temporary or other borrowing for the Fund (if applicable), or (iii) the effectiveness of related Fund transactions
such as hedges, as applicable.

Various financial industry groups are planning for the transition away
from LIBOR, but there are obstacles to converting certain longer term securities and transactions to a new benchmark. In June 2017, the
Alternative Reference Rates Committee, a group of large U.S. banks working with the Federal Reserve, announced its selection of a new
Secured Overnight Financing Rate (“SOFR”), which is intended to be a broad measure of secured overnight U.S. Treasury repo
rates, as an appropriate replacement for LIBOR. Bank working groups and regulators in other countries have suggested other alternatives
for their markets, including the Sterling Overnight Interbank Average Rate (“SONIA”) in England. Both SOFR and SONIA, as well
as certain other proposed replacement rates, are materially different from LIBOR, and changes in the applicable spread for financial instruments
transitioning away from LIBOR need to be made to accommodate the differences. Liquid markets for newly-issued instruments that use an
alternative reference rate are still developing. Consequently, there may be challenges for a Fund to enter into hedging transactions against
instruments tied to alternative reference rates until a market for such hedging transactions develops.

  Additionally, while some existing LIBOR-based instruments may contemplate a scenario where LIBOR is no longer available by providing for an alternative or “fallback” rate-setting methodology, there may be significant uncertainty regarding the effectiveness of any such alternative methodologies to replicate LIBOR. Not all existing LIBOR-based instruments have such fallback provisions, and many that do, do not contemplate the permanent cessation of LIBOR. While it is expected that market participants will amend legacy financial instruments referencing LIBOR to include fallback provisions to alternative reference rates, there remains uncertainty regarding the willingness and ability of parties to add or amend such fallback provisions in legacy instruments maturing after the end of 2021, particularly with respect to legacy cash products. Although there are ongoing efforts among certain government entities and other organizations to address these uncertainties, the ultimate effectiveness of such efforts in not yet known.
  Any effects of the transition away from LIBOR and the adoption of alternative reference rates, as well as other unforeseen effects, could result in losses to the Fund. Since the usefulness of LIBOR as a benchmark could deteriorate during the transition period, these effects may occur prior to the discontinuation. Furthermore, the risks associated with the expected discontinuation of LIBOR and transition to replacement rates may be exacerbated if an orderly transition to an alternative reference rate is not completed in a timely manner.
Liquidity or Protective Put Agreements See also “Derivative Instruments and Related Risks” herein.  The Fund may enter into a separate agreement with the seller of an instrument or some other person granting the Fund the right to put the instrument to the seller thereof or the other person at an agreed upon price.  Interest income generated by certain municipal bonds with put or demand features may be taxable.

Calvert Mortgage Access Fund 64 SAI dated [______], 2022

 

 

Loans Loans may be primary, direct investments or investments in loan assignments or participation interests.  A loan assignment represents a portion or the entirety of a loan and a portion of the entirety of a position previously attributable to a different lender. The purchaser of an assignment typically succeeds to all the rights and obligations under the loan agreement and has the same rights and obligations as the assigning investor.  However, assignments through private negotiations may cause the purchaser of an assignment to have different and more limited rights than those held by the assigning investor.  Loan participation interests are interests issued by a lender or other entity and represent a fractional interest in a loan. The Fund typically will have a contractual relationship only with the financial institution that issued the participation interest. As a result, the Fund may have the right to receive payments of principal, interest and any fees to which it is entitled only from the financial institution and only upon receipt by such entity of such payments from the borrower. In connection with purchasing a participation interest, the Fund generally will have no right to enforce compliance by the borrower with the terms of the loan agreement, nor any rights with respect to any funds acquired by other investors through set-off against the borrower and the Fund may not directly benefit from the collateral supporting the loan in which it has purchased the participation interest. As a result, the Fund may assume the credit risk of both the borrower and the financial institution issuing the participation interest. In the event of the insolvency of the entity issuing a participation interest, the Fund may be treated as a general creditor of such entity.
  Loans may be originated by a lending agent, such as a financial institution or other entity, on behalf of a group or “syndicate” of loan investors (the “Loan Investors”).  In such a case, the agent administers the terms of the loan agreement and is responsible for the collection of principal, and interest payments from the borrower and the apportionment of these payments to the Loan Investors. Failure by the agent to fulfill its obligations may delay or adversely affect receipt of payment by the Fund. Furthermore, unless under the terms of a loan agreement or participation (as applicable) the Fund has direct recourse against the borrower, the Fund must rely on the Agent and the other Loan Investors to pursue appropriate remedies against the borrower.
  Loan investments may be made at par or at a discount or premium to par.  The interest payable on a loan may be fixed or floating rate, and paid in cash or in-kind.  In connection with transactions in loans, the Fund may be subject to facility or other fees.  Loans may be secured by specific collateral or other assets of the borrower, guaranteed by a third party, unsecured or subordinated.  During the term of a loan, the value of any collateral securing the loan may decline in value, causing the loan to be under collateralized. Collateral may consist of assets that may not be readily liquidated, and there is no assurance that the liquidation of such assets would satisfy fully a borrower’s obligations under the loan. In addition, if a loan is foreclosed, the Fund could become part owner of the collateral and would bear the costs and liabilities associated with owning and disposing of such collateral.
  A lender’s repayment and other rights primarily are determined by governing loan, assignment or participation documents, which (among other things) typically establish the priority of payment on the loan relative to other indebtedness and obligations of the borrower.  A borrower typically is required to comply with certain covenants contained in a loan agreement between the borrower and the holders of the loan.  The types of covenants included in loan agreements generally vary depending on market conditions, the creditworthiness of the issuer, and the nature of the collateral securing the loan.  Loans with fewer covenants that restrict activities of the borrower may provide the borrower with more flexibility to take actions that may be detrimental to the loan holders and provide fewer investor protections in the event covenants are breached.  The Fund may experience relatively greater realized or unrealized losses or delays and expense in enforcing its rights with respect to loans with fewer restrictive covenants.  Loans to entities located outside of the U.S. (including to sovereign entities) may have substantially different lender protections and covenants as compared to loans to U.S. entities and may involve greater risks.  In the event of bankruptcy, applicable law may impact a lender’s ability to enforce its rights.  The Fund may have difficulties and incur expense enforcing its rights with respect to non-U.S. loans and such loans could be subject to bankruptcy laws that are materially different than in the U.S.  Sovereign entities may be unable or unwilling to meet their obligations under a loan due to budgetary limitations or economic or political changes within the country.   

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  Investing in loans involves the risk of default by the borrower or other party obligated to repay the loan.  In the event of insolvency of the borrower or other obligated party, the Fund may be treated as a general creditor of such entity unless it has rights that are senior to that of other creditors or secured by specific collateral or assets of the borrower.  Fixed-rate loans are also subject to the risk that their value will decline in a rising interest rate environment.  This risk is mitigated for floating-rate loans, where the interest rate payable on the loan resets periodically by reference to a base lending rate.  The base lending rate usually is the London Interbank Offered Rate (“LIBOR”), the Federal Reserve federal funds rate, the prime rate or other base lending rates used by commercial lenders. LIBOR usually is an average of the interest rates quoted by several designated banks as the rates at which they pay interest to major depositors in the London interbank market on U.S. dollar-denominated deposits.
  Many financial instruments use or may use a floating rate based on LIBOR, which is the offered rate for short-term Eurodollar deposits between major international banks.  On July 27, 2017, the head of the United Kingdom’s Financial Conduct Authority announced a desire to phase out the use of LIBOR beginning at the end of 2021.  The ICE Benchmark Administration Limited, the administrator of LIBOR, ceased publishing certain LIBOR settings on December 31, 2021, and is expected to cease publishing the remaining LIBOR settings on June 30, 2023.  Although the transition process away from LIBOR has become increasingly well-defined, the impact on financial instruments that utilize LIBOR remains uncertain.  See “LIBOR Transition and Associated Risk” herein.
  The Fund will take whatever action it considers appropriate in the event of anticipated financial difficulties, default or bankruptcy of the borrower or other entity obligated to repay a loan. Such action may include: (i) retaining the services of various persons or firms (including affiliates of the investment adviser) to evaluate or protect any collateral or other assets securing the loan or acquired as a result of any such event; (ii) managing (or engaging other persons to manage) or otherwise dealing with any collateral or other assets so acquired; and (iii) taking such other actions (including, but not limited to, payment of operating or similar expenses relating to the collateral) as the investment adviser may deem appropriate to reduce the likelihood or severity of loss on the Fund’s investment and/or maximize the return on such investment.  The Fund will incur additional expenditures in taking protective action with respect to loans in (or anticipated to be in) default and assets securing such loans.  In certain circumstances, the Fund may receive equity or equity-like securities from a borrower to settle the loan or may acquire an equity interest in the borrower.  Representatives of the Fund also may join creditor or similar committees relating to loans.
  Lenders can be sued by other creditors and the debtor and its shareholders. Losses could be greater than the original loan amount and occur years after the loan’s recovery. If a borrower becomes involved in bankruptcy proceedings, a court may invalidate the Fund’s security interest in any loan collateral or subordinate the Fund’s rights under the loan agreement to the interests of the borrower’s unsecured creditors or cause interest previously paid to be refunded to the borrower. There are also other events, such as the failure to perfect a security interest due to faulty documentation or faulty official filings, which could lead to the invalidation of the Fund’s security interest in loan collateral. If any of these events occur, the Fund’s performance could be negatively affected.
  Interests in loans generally are not listed on any national securities exchange or automated quotation system and no active market may exist for many loans, making them illiquid. As described below, a secondary market exists for many Senior Loans, but it may be subject to irregular trading activity, wide bid/ask spreads and extended trade settlement periods.
  From time to time the investment adviser and its affiliates may borrow money from various banks in connection with their business activities. Such banks may also sell interests in loans to or acquire them from the Fund or may be intermediate participants with respect to loans in which the Fund owns interests. Such banks may also act as agents for loans held by the Fund.
  To the extent that legislation or state or federal regulators that regulate certain financial institutions impose additional requirements or restrictions with respect to the ability of such institutions to make loans, particularly in connection with highly leveraged transactions, the availability of loans for investment may be adversely affected. Further, such legislation or regulation could depress the market value of loans.

Calvert Mortgage Access Fund 66 SAI dated [______], 2022

 

  For additional disclosures relating to Junior and Senior Loans, see “Junior Loans” and “Senior Loans” herein.
Lower Rated Investments Lower rated investments (commonly referred to as “junk”) are of below investment grade quality and generally provide greater income potential and/or increased opportunity for capital appreciation than higher quality investments but they also typically entail greater potential price volatility and principal and income risk.  Lower rated investments are regarded as predominantly speculative with respect to the entity’s continuing ability to make timely principal and interest payments.  Also, their yields and market values may fluctuate more than higher rated investments.  Fluctuations in value do not affect the cash income from lower rated investments, but are reflected in the Fund’s net asset value.  The greater risks and fluctuations in yield and value occur, in part, because investors generally perceive issuers of lower rated and unrated investments to be less creditworthy. The secondary market for lower rated investments may be less liquid than the market for higher grade investments.
Master Limited Partnerships (“MLPs”) MLPs
are publicly-traded limited partnership interests or units. An MLP that invests in a particular industry (e.g., oil and gas) will be
harmed by detrimental economic events within that industry. As partnerships, MLPs may be subject to less regulation (and less
protection for investors) under state laws than corporations. In addition, MLPs may be subject to state taxation in certain
jurisdictions, which may reduce the amount of income paid by an MLP to its investors. Effective for taxable years beginning after
December 31, 2017 and before January 1, 2026, the Tax Cuts and Jobs Act generally allows individuals and certain other non-corporate entities, such as
partnerships, a deduction for 20% of “qualified publicly traded partnership income” such as income from
MLPs.  However, the law does not include any provision for a regulated investment company to pass the character of its
qualified publicly traded partnership income through to its shareholders.  As a result, an investor who invests directly
in MLPs will be able to receive the benefit of that deduction, while a shareholder of the Fund will not.
Money Market Instruments Money market instruments include short term, high quality, U.S. dollar denominated instruments such as commercial paper, certificates of deposit or time deposits and bankers’ acceptances issued by U.S. or foreign banks, and Treasury bills and other obligations with a maturity of one year or less, including those issued or guaranteed by U.S. Government agencies and instrumentalities.  See “U.S. Government Securities” below. Certificates of deposit or time deposits are certificates issued against funds deposited in a commercial bank, are for a definite period of time, earn a specified rate of return, and are normally negotiable. Bankers’ acceptances are short-term credit instruments used to finance the import, export, transfer or storage of goods. They are termed “accepted” when a bank guarantees their payment at maturity.
  The obligations of foreign branches of U.S. banks may be general obligations of the parent bank in addition to the issuing branch, or may be limited by the terms of a specific obligation and by governmental regulation.  Payment of interest and principal upon these obligations may also be affected by governmental action in the country of domicile of the branch (generally referred to as sovereign risk). In addition, evidence of ownership of portfolio securities may be held outside of the U.S. and generally will be subject to the risks associated with the holding of such property overseas. Various provisions of U.S. law governing the establishment and operation of domestic branches do not apply to foreign branches of domestic banks. The obligations of U.S. branches of foreign banks may be general obligations of the parent bank in addition to the issuing branch, or may be limited by the terms of a specific obligation and by federal and state regulation as well as by governmental action in the country in which the foreign bank has its head office.

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  Money market instruments are often acquired directly from the issuers thereof or otherwise are normally traded on a net basis (without commission) through broker-dealers and banks acting for their own account. Such firms attempt to profit from such transactions by buying at the bid price and selling at the higher asked price of the market, and the difference is customarily referred to as the spread. Money market instruments may be adversely affected by market and economic events, such as a sharp rise in prevailing short-term interest rates; adverse developments in the banking industry, which issues or guarantees many money market securities; adverse economic, political or other developments affecting domestic issuers of money market securities; changes in the credit quality of issuers; and default by a counterparty. These securities may be subject to federal income, state income and/or other taxes.  Instead of investing in money market instruments directly, the Fund may invest in an affiliated or unaffiliated money market fund. Recent actions by governmental authorities in response to the economic disruptions caused by the COVID-19 pandemic have included dramatic reductions in interest rates, which in some cases could result in negative rates on investments in money market funds and similar cash management products. During unusual market conditions, the Fund may invest up to 100% of its assets in cash or cash equivalents temporarily, which may be inconsistent with its investment objective(s) and other policies.
Mortgage-Backed Securities (“MBS”) MBS are “pass through” securities, meaning that a pro rata share of regular interest and principal payments, as well as unscheduled early prepayments, on the underlying mortgage pool is passed through monthly to the holder.  MBS may include conventional mortgage pass through securities, participation interests in pools of adjustable and fixed rate mortgage loans, stripped securities (described herein), floating rate mortgage-backed securities and certain classes of multiple class CMOs. MBS pay principal to the holder over their term, which differs from other forms of debt securities that normally provide for principal payment at maturity or specified call dates. MBS are subject to the general risks associated with investing in real estate securities; that is, they may lose value if the value of the underlying real estate to which a pool of mortgages relates declines.  In addition, investments in MBS involve certain specific risks, including the failure of a party to meet its commitments under the related operative documents, adverse interest rate changes, and the effects of prepayments on mortgage cash flows and that any guarantee or other structural feature, if present, is insufficient to enable the timely payment of interest and principal on the MBS. Although certain MBS are guaranteed as to timely payment of interest and principal by a government-sponsored enterprise, the market price for such securities is not guaranteed and will fluctuate.  Certain MBS may be purchased on a when-issued basis subject to certain limitations and requirements.
  There are currently four types of MBS: (1) those issued by the U.S. Government or one of its agencies or instrumentalities, such as the Government National Mortgage Association (“GNMA”), the Federal National Mortgage Association (“FNMA”) and the Federal Home Loan Mortgage Corporation (“FHLMC”); (2) those issued by private issuers that represent an interest in or are collateralized by pass through securities issued or guaranteed by the U.S. Government or one of its agencies or instrumentalities; (3) those issued by the U.S. Government or one of its agencies or instrumentalities without a government guarantee, such as credit risk transfer bonds; and (4) those issued by private issuers that represent an interest in or are collateralized by whole mortgage loans or pass through securities without a government guarantee but that usually have some form of private credit enhancement.  Privately issued MBS are structured similar to GNMA, FNMA and FHLMC MBS, and are issued by originators or and investors in mortgage loans, including depositary institutions mortgage banks and special purpose subsidiaries of the foregoing.

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  GNMA Certificates and FNMA Mortgage-Backed Certificates are MBS representing part ownership of a pool of mortgage loans. GNMA loans (issued by lenders such as mortgage bankers, commercial banks and savings and loan associations) are either insured by the Federal Housing Administration or guaranteed by the Veterans Administration. A pool of such mortgages is assembled and, after being approved by GNMA, is offered to investors through securities dealers. Once such pool is approved by GNMA, the timely payment of interest and principal on the Certificates issued representing such pool is guaranteed by the full faith and credit of the U.S. Government. GNMA is a wholly owned U.S. Government corporation within the Department of Housing and Urban Development.  FNMA, a federally chartered corporation owned entirely by private stockholders, purchases both conventional and federally insured or guaranteed residential mortgages from various entities, including savings and loan associations, savings banks, commercial banks, credit unions and mortgage bankers, and packages pools of such mortgages in the form of pass-through securities generally called FNMA Mortgage-Backed Certificates, which are guaranteed as to timely payment of principal and interest by FNMA but are not backed by the full faith and credit of the U.S. Government; however, they are supported by the right of FNMA to borrow from the U.S. Treasury Department.
   FHLMC, a corporate instrumentality of the U.S. Government created by Congress for the purposes of increasing the availability of mortgage credit for residential housing, issues participation certificates (“PCs”) representing undivided interest in FHLMC’S mortgage portfolio. While FHLMC guarantees the timely payment of interest and ultimate collection of the principal of its PCs, its PCs are not backed by the full faith and credit of the U.S. Government. FHLMC PCs differ from GNMA Certificates in that the mortgages underlying the PCs are monthly “conventional” mortgages rather than mortgages insured or guaranteed by a federal agency or instrumentality. However, in several other respects, such as the monthly pass-through of interest and principal (including unscheduled prepayments) and the unpredictability of future unscheduled prepayments on the underlying mortgage pools, FHLMC PCs are similar to GNMA Certificates.  
  While it is not possible to accurately predict the life of a particular issue of MBS, the actual life of any such security is likely to be substantially less than the final maturities of the mortgage loans underlying the security. This is because unscheduled early prepayments of principal on MBS will result from the prepayment, refinancings or foreclosure of the underlying mortgage loans in the mortgage pool. Prepayments of MBS may not be able to be reinvested at the same interest rate.  Because of the regular scheduled payments of principal and the early unscheduled prepayments of principal, MBS are less effective than other types of obligations as a means of “locking-in” attractive long-term interest rates. As a result, this type of security may have less potential for capital appreciation during periods of declining interest rates than other U.S. Government securities of comparable maturities, although many issues of MBS may have a comparable risk of decline in market value during periods of rising interest rates. If MBS are purchased at a premium above their par value, a scheduled payment of principal and an unscheduled prepayment of principal, which would be made at par, will accelerate the realization of a loss equal to that portion of the premium applicable to the payment or prepayment. If MBS have been purchased at a discount from their par value, both a scheduled payment of principal and an unscheduled prepayment of principal will increase current returns and will accelerate the recognition of income, which, when distributed to Fund shareholders, will be taxable as ordinary income.
Mortgage Dollar Rolls In a mortgage dollar roll, the Fund sells MBS for delivery in the current month and simultaneously contracts to repurchase substantially similar (same type, coupon and maturity) MBS on a specified future date. During the roll period, the Fund forgoes principal and interest paid on the MBS.  The Fund is compensated by the difference between the current sales price and the lower forward price for the future purchase (often referred to as the “drop”) as well as by the interest earned on the cash proceeds of the initial sales. Cash proceeds may be invested in instruments that are permissible investments for the Fund.  The use of mortgage dollar rolls is a speculative technique involving leverage.  A “covered roll” is a specific type of dollar roll for which there is an offsetting cash position or permissible liquid assets earmarked or in a segregated account to secure the obligation for the forward commitment to buy MBS, or a cash equivalent security position that matures on or before the forward settlement date of the dollar roll transaction. The Fund will enter into only covered rolls. Covered rolls are not treated as a borrowing or other senior security and will be excluded from the calculation of the Fund’s borrowings and other senior securities.

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Municipal Lease Obligations (“MLOs”) An MLO is a bond that is secured by lease payments made by the party, typically a state or municipality, leasing the facilities (e.g., schools or office buildings) that were financed by the bond.  Such lease payments may be subject to annual appropriation or may be made only from revenues associated with the facility financed.  In other cases, the leasing state or municipality is obligated to appropriate funds from its general tax revenues to make lease payments as long as it utilizes the leased property.  MLOs, like other municipal debt obligations, are subject to the risk of non-payment. Although MLOs do not constitute general obligations of the issuer for which the issuer’s unlimited taxing power is pledged, a lease obligation is frequently backed by the issuer’s covenant to budget for, appropriate and make the payments due under the lease obligation.  However, certain lease obligations contain “non-appropriation” clauses, which provide that the issuer has no obligation to make lease or installment purchase payments in future years unless money is appropriated for such purpose on a yearly basis. Although “non-appropriation” lease obligations may be secured by the leased property, disposition of the property in the event of foreclosure might prove difficult. A certificate of participation (also referred to as a “participation”) in a municipal lease is an instrument evidencing a pro rata share in a specific pledged revenue stream, usually lease payments by the issuer that are typically subject to annual appropriation.  The certificate generally entitles the holder to receive a share, or participation, in the payments from a particular project.
  MLOs and participations therein represent a type of financing that may not have the depth of marketability associated with more conventional securities and, as such, they may be less liquid than conventional securities.  Certain MLOs may be deemed illiquid for the purpose of the Fund’s limitation on investments in illiquid investments.
  The ability of issuers of MLOs to make timely lease payments may be adversely impacted in general economic downturns and as relative governmental cost burdens are allocated and reallocated among federal, state and local governmental units. Such non-payment would result in a reduction of income from and value of the obligation. Issuers of MLOs might seek protection under the bankruptcy laws. In the event of bankruptcy of such an issuer, holders of MLOs could experience delays and limitations with respect to the collection of principal and interest on such MLOs and may not, in all circumstances, be able to collect all principal and interest to which it is entitled. To enforce its rights in the event of a default in lease payments, the Fund might take possession of and manage the assets securing the issuer’s obligations on such securities or otherwise incur costs to protect its rights, which may increase the Fund’s operating expenses and adversely affect the net asset value of the Fund. When the lease contains a non-appropriation clause, however, the failure to pay would not be a default and the Fund would not have the right to take possession of the assets. Any income derived from the Fund’s ownership or operation of such assets may not be tax-exempt.
Municipal Obligations Municipal obligations include debt obligations issued to obtain funds for various public purposes, including the construction of a wide range of public facilities, refunding of outstanding obligations and obtaining funds for general operating expenses and loans to other public institutions and facilities.  Certain types of bonds are issued by or on behalf of public authorities to finance various privately owned or operated facilities, including certain facilities for the local furnishing of electric energy or gas, sewage facilities, solid waste disposal facilities and other specialized facilities. Municipal obligations include bonds as well as tax-exempt commercial paper, project notes and municipal notes such as tax, revenue and bond anticipation notes of short maturity, generally less than three years. While most municipal bonds pay a fixed rate of interest semiannually in cash, there are exceptions. Some bonds pay no periodic cash interest, but rather make a single payment at maturity representing both principal and interest. Some bonds may pay interest at a variable or floating rate.  Bonds may be issued or subsequently offered with interest coupons materially greater or less than those then prevailing, with price adjustments reflecting such deviation.  Municipal obligations also include trust certificates representing interests in municipal securities held by a trustee. The trust certificates may evidence ownership of future interest payments, principal payments or both on the underlying securities.

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  In general, there are three categories of municipal obligations, the interest on which is exempt from federal income tax and is not a tax preference item for purposes of the AMT: (i) certain “public purpose” obligations (whenever issued), which include obligations issued directly by state and local governments or their agencies to fulfill essential governmental functions; (ii) certain obligations issued before August 8, 1986 for the benefit of non-governmental persons or entities; and (iii) certain “private activity bonds” issued after August 7, 1986, which include “qualified Section 501(c)(3) bonds” or refundings of certain obligations included in the second category. Opinions relating to the validity of municipal bonds, exclusion of municipal bond interest from an investor’s gross income for federal income tax purposes and, where applicable, state and local income tax, are rendered by bond counsel to the issuing authorities at the time of issuance.
  Interest on certain “private activity bonds” issued after August 7, 1986 is exempt from regular federal income tax, but such interest (including a distribution by the Fund derived from such interest) is treated as a tax preference item that could subject the recipient to or increase the recipient’s liability for the AMT.
  The two principal classifications of municipal bonds are “general obligation” and “revenue” bonds. Issuers of general obligation bonds include states, counties, cities, towns and regional districts. The proceeds of these obligations are used to fund a wide range of public projects, including the construction or improvement of schools, highways and roads, water and sewer systems and a variety of other public purposes. The basic security of general obligation bonds is the issuer’s pledge of its faith, credit, and taxing power for the payment of principal and interest. The taxes that can be levied for the payment of debt service may be limited or unlimited as to rate and amount.
  Typically, the only security for a limited obligation or revenue bond is the net revenue derived from a particular facility or class of facilities financed thereby or, in some cases, from the proceeds of a special tax or other special revenues. Revenue bonds have been issued to fund a wide variety of revenue-producing public capital projects including: electric, gas, water and sewer systems; highways, bridges and tunnels; port and airport facilities; colleges and universities; hospitals; and convention, recreational, tribal gaming and housing facilities. Although the security behind these bonds varies widely, many lower rated bonds provide additional security in the form of a debt service reserve fund that may also be used to make principal and interest payments on the issuer’s obligations. In addition, some revenue obligations (as well as general obligations) are insured by a bond insurance company or backed by a letter of credit issued by a banking institution.  Revenue bonds also include, for example, pollution control, health care and housing bonds, which, although nominally issued by municipal authorities, are generally not secured by the taxing power of the municipality but by the revenues of the authority derived from payments by the private entity that owns or operates the facility financed with the proceeds of the bonds. Obligations of housing finance authorities have a wide range of security features, including reserve funds and insured or subsidized mortgages, as well as the net revenues from housing or other public projects. Many of these bonds do not generally constitute the pledge of the credit of the issuer of such bonds. The credit quality of such revenue bonds is usually directly related to the credit standing of the user of the facility being financed or of an institution which provides a guarantee, letter of credit or other credit enhancement for the bond issue.  The Fund may on occasion acquire revenue bonds that carry warrants or similar rights covering equity securities. Such warrants or rights may be held indefinitely, but if exercised, the Fund anticipates that it would, under normal circumstances, dispose of any equity securities so acquired within a reasonable period of time.  Investing in revenue bonds may involve (without limitation) the following risks.
  Hospital bond ratings are often based on feasibility studies that contain projections of expenses, revenues and occupancy levels.   A hospital’s income available to service its debt may be influenced by demand for hospital services, management capabilities, the service area economy, efforts by insurers and government agencies to limit rates and expenses, competition, availability and expense of malpractice insurance, and Medicaid and Medicare funding.

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  Education-related bonds are comprised of two types: (i) those issued to finance projects for public and private colleges and universities, charter schools and private schools, and (ii) those representing pooled interests in student loans. Bonds issued to supply educational institutions with funding are subject to many risks, including the risks of unanticipated revenue decline, primarily the result of decreasing student enrollment, decreasing state and federal funding, or changes in general economic conditions. Additionally, higher than anticipated costs associated with salaries, utilities, insurance or other general expenses could impair the ability of a borrower to make annual debt service payments. Student loan revenue bonds are generally offered by state (or sub-state) authorities or commissions and are backed by pools of student loans. Underlying student loans may be guaranteed by state guarantee agencies and may be subject to reimbursement by the United States Department of Education through its guaranteed student loan program. Others may be private, uninsured loans made to parents or students that may be supported by reserves or other forms of credit enhancement. Cash flows supporting student loan revenue bonds are impacted by numerous factors, including the rate of student loan defaults, seasoning of the loan portfolio, and student repayment deferral periods of forbearance. Other risks associated with student loan revenue bonds include potential changes in federal legislation regarding student loan revenue bonds, state guarantee agency reimbursement and continued federal interest and other program subsidies currently in effect.
  Transportation debt may be issued to finance the construction of airports, toll roads, highways, or other transit facilities. Airport bonds are dependent on the economic conditions of the airport’s service area and may be affected by the business strategies and fortunes of specific airlines. They may also be subject to competition from other airports and modes of transportation. Air traffic generally follows broader economic trends and is also affected by the price and availability of fuel. Toll road bonds are also affected by the cost and availability of fuel as well as toll levels, the presence of competing roads and the general economic health of an area. Fuel costs, transportation taxes and fees, and availability of fuel also affect other transportation-related securities, as do the presence of alternate forms of transportation, such as public transportation.
 

Industrial development bonds (“IDBs”) are normally secured
only by the revenues from the project and not by state or local government tax payments, they are subject to a wide variety of risks,
many of which relate to the nature of the specific project. Generally, IDBs are sensitive to the risk of a slowdown in the economy.

Electric utilities face problems in financing large construction programs
in an inflationary period, cost increases and delay occasioned by safety and environmental considerations (particularly with respect to
nuclear facilities), difficulty in obtaining fuel at reasonable prices, and in achieving timely and adequate rate relief from regulatory
commissions, effects of energy conservation and limitations on the capacity of the capital market to absorb utility debt.

Water and sewer revenue bonds are generally secured by the fees charged
to each user of the service. The issuers of water and sewer revenue bonds generally enjoy a monopoly status and latitude in their ability
to raise rates. However, lack of water supply due to insufficient rain, run-off, or snow pack can be a concern and has led to past defaults.
Further, public resistance to rate increases, declining numbers of customers in a particular locale, costly environmental litigation,
and federal environmental mandates are challenges faced by issuers of water and sewer bonds.

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  The obligations of any person or entity to pay the principal of and interest on a municipal obligation are subject to the provisions of bankruptcy, insolvency and other laws affecting the rights and remedies of creditors, such as the Federal Bankruptcy Act, and laws, if any, that may be enacted by Congress or state legislatures extending the time for payment of principal or interest, or both, or imposing other constraints upon enforcement of such obligations. Certain bond structures may be subject to the risk that a taxing authority may issue an adverse ruling regarding tax-exempt status.  There is also the possibility that as a result of adverse economic conditions (including unforeseen financial events, natural disasters and other conditions that may affect an issuer’s ability to pay its obligations), litigation or other conditions, the power or ability of any person or entity to pay when due principal of and interest on a municipal obligation may be materially affected or interest and principal previously paid may be required to be refunded. There have been instances of defaults and bankruptcies involving municipal obligations that were not foreseen by the financial and investment communities. The Fund will take whatever action it considers appropriate in the event of anticipated financial difficulties, default or bankruptcy of either the issuer of any municipal obligation or of the underlying source of funds for debt service. Such action may include: (i) retaining the services of various persons or firms (including affiliates of the investment adviser) to evaluate or protect any real estate, facilities or other assets securing any such obligation or acquired by the Fund as a result of any such event; (ii) managing (or engaging other persons to manage) or otherwise dealing with any real estate, facilities or other assets so acquired; and (iii) taking such other actions as the adviser (including, but not limited to, payment of operating or similar expenses of the underlying project) may deem appropriate to reduce the likelihood or severity of loss on the fund’s investment.  The Fund will incur additional expenditures in taking protective action with respect to portfolio obligations in (or anticipated to be in) default and assets securing such obligations.
 

Historically, municipal bankruptcies have been rare and certain provisions
of the U.S. Bankruptcy Code governing such bankruptcy are unclear. Further, the application of state law to municipal obligation issuers
could produce varying results among the states or among municipal obligation issuers within a state. These uncertainties could have a
significant impact on the prices of the municipal obligations in which the Fund invests. There could be economic, business or political
developments or court decisions that adversely affect all municipal obligations in the same sector. Developments such as changes in healthcare
regulations, environmental considerations related to construction, construction cost increases and labor problems, failure of healthcare
facilities to maintain adequate occupancy levels, and inflation can affect municipal obligations in the same sector. As the similarity
in issuers of municipal obligations held by the Fund increases, the potential for fluctuations in the Fund’s share price also may
increase.

The Commonwealth of Puerto Rico and its related issuers are currently
experiencing financial difficulties, including persistent government budget deficits, underfunded public pension benefit obligations,
underfunded government retirement systems, sizable debt service obligations and a high unemployment rate. Several rating agencies have
downgraded a number of securities issued in Puerto Rico to below investment-grade, and numerous issuers have entered Title III of the
Puerto Rico Oversight, Management and Economic Stability Act (“PROMESA”), which is similar to bankruptcy protection, through
which the Commonwealth of Puerto Rico can restructure its debt. However, Puerto Rico’s case is the first ever heard under PROMESA and
there is no existing case precedent to guide the proceedings. Accordingly, Puerto Rico’s debt restructuring process could take significantly
longer than traditional municipal bankruptcy proceedings. Further, it is not clear whether a debt restructuring process will ultimately
be approved or, if so, the extent to which it will apply to Puerto Rico municipal securities sold by an issuer other than the territory.
A debt restructuring could reduce the principal amount due, the interest rate, the maturity, and other terms of Puerto Rico municipal
securities, which could adversely affect the value of Puerto Rican municipal securities. Further legislation by the U.S. Congress, or
actions by the oversight board established by PROMESA, or court approval of a debt restructuring deal could have a negative impact on
the marketability, liquidity, or value of certain investments held by the Fund and could reduce the Fund’s performance.

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  In addition, Puerto Rico has faced significant out-migration relating to its economic difficulties, eroding the Commonwealth’s economic base and creating additional further uncertainty regarding its ability to meet its future repayment obligations. The Puerto Rican constitution prioritizes general obligation bonds over revenue bonds, so that all tax revenues, even those pledged to revenue bondholders, can be applied first to general obligation bonds and other Commonwealth-guaranteed debt if other revenues are insufficient to satisfy such obligations.
 

The secondary market for some municipal obligations issued within a
state (including issues that are privately placed with the Fund) is less liquid than that for taxable debt obligations or other more widely
traded municipal obligations. No established resale market exists for certain of the municipal obligations in which the Fund may invest.
The market for obligations rated below investment grade is also likely to be less liquid than the market for higher rated obligations.
As a result, the Fund may be unable to dispose of these municipal obligations at times when it would otherwise wish to do so at the prices
at which they are valued.

Municipal obligations that are rated below investment grade but that,
subsequent to the assignment of such rating, are backed by escrow accounts containing U.S. Government obligations may be determined by
the investment adviser to be of investment grade quality for purposes of the Fund’s investment policies. In the case of a defaulted
obligation, the Fund may incur additional expense seeking recovery of its investment. Defaulted obligations are denoted in the “Schedule
of Investments” in the “Financial Statements” included in the Fund’s reports to shareholders.

The yields on municipal obligations depend on a variety of factors,
including purposes of the issue and source of funds for repayment, general money market conditions, general conditions of the municipal
bond market, size of a particular offering, maturity of the obligation and rating of the issue. The ratings of Moody’s, S&P
and Fitch represent their opinions as to the quality of the municipal obligations which they undertake to rate, and in the case of insurers,
other factors including the claims-paying ability of such insurer. It should be emphasized, however, that ratings are based on judgment
and are not absolute standards of quality. Consequently, municipal obligations with the same maturity, coupon and rating may have different
yields while obligations of the same maturity and coupon with different ratings may have the same yield. In addition, the market price
of such obligations will normally fluctuate with changes in interest rates, and therefore the net asset value of the Fund will be affected
by such changes.

Operational Risk The Fund’s service providers, including the investment adviser, may experience disruptions or operating errors that could negatively impact the Fund. Disruptive events, including (but not limited to) natural disasters and public health crises, may adversely affect the Fund’s ability to conduct business, in particular if the Fund’s employees or the employees of its service providers are unable or unwilling to perform their responsibilities as a result of any such event. While service providers are expected to have appropriate operational risk management policies and procedures, their methods of operational risk management may differ from the Fund’s in the setting of priorities, the personnel and resources available or the effectiveness of relevant controls. It also is not possible for Fund service providers to identify all of the operational risks that may affect the Fund or to develop processes and controls to completely eliminate or mitigate their occurrence or effects.

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Option Contracts See also “Derivative Instruments and Related Risks” herein.  An option contract is a contract that gives the holder of the option, in return for a premium, the right to buy from (in the case of a call) or sell to (in the case of a put) the writer of the option the reference instrument underlying the option (or the cash value of the index) at a specified exercise price at any time during the term of the option. The writer of an option on a security has the obligation upon exercise of the option to deliver the reference instrument (or the cash) upon payment of the exercise price or to pay the exercise price upon delivery of the reference instrument (or the cash). Upon exercise of an index option, the writer of an option on an index is obligated to pay the difference between the cash value of the index and the exercise price multiplied by the specified multiplier for the index option. Options may be “covered,” mean