EVM Eaton Vance California Municipal Bond Fund

Eaton Vance Municipal Bond Fund

Investment Objective and Principal Strategies

The Fund’s investment objective is to provide current income exempt from federal income tax.

During normal market conditions, at least 80% of the Fund’s net assets will be invested in municipal obligations, the interest on which is exempt from federal income tax, including the alternative minimum tax (“AMT”) and that are rated A or better by Moody’s Investors Service, Inc. (“Moody’s”), S&P Global Ratings (“S&P”) or Fitch Ratings (“Fitch”). The foregoing 80% policy may not be changed without shareholder approval. Under normal market conditions, the Fund expects to be fully invested (at least 95% of its net assets) in accordance with its investment objective. The Fund may invest up to 20% of its net assets in municipal obligations rated BBB/Baa or below (or unrated obligations deemed by the Fund’s adviser, Eaton Vance Management (“Eaton Vance”), to be of equivalent quality), provided that not more than 15% of its net assets may be invested in municipal obligations rated below B (or unrated obligations deemed by Eaton Vance to be of equivalent quality) and may invest up to 20% of its net assets in bonds on which the interest is subject to the AMT. When a municipal obligation is split rated (meaning rated in different categories by Moody’s, S&P or Fitch) the Fund will deem the higher rating to apply.

The Fund may purchase derivative instruments, which derive their value from another instrument, security or index, including financial futures contracts and related options, interest rate swaps and forward rate contracts. The Fund also may invest in residual interests of a trust (the “trust”) that holds municipal securities (“RIBs”). The trust will also issue floating-rate notes to third parties that may be senior to a Fund’s residual interest. The Fund may purchase and sell financial futures contracts and related options, including futures contracts and related options based on various debt securities and securities indices, as well as interest rate swaps and forward rate contracts, to seek to hedge against changes in interest rates or for other risk management purposes.

Except for certain fundamental investment restrictions set forth in the Fund’s registration statement and the 80% requirement pertaining to investment in municipal and insured municipal obligations set forth above, the investment objective and policies of the Fund may be changed by the Board without shareholder action.

The Fund employs leverage to seek opportunities for additional income. Leverage may amplify the effect on the Fund’s NAV of any increase or decrease in the value of investments held. The Fund generally will not use leverage if the investment adviser anticipates that it would result in a lower return to shareholders for any significant amount of time. There can be no assurance that the use of leverage will be successful.

Principal Risks

Market Discount Risk. As with any security, the market value of the common shares may increase or decrease from the amount initially paid for the common shares. The Fund’s common shares have traded both at a premium and at a discount relative to NAV. The shares of closed-end management investment companies frequently trade at a discount from their NAV. This is a risk separate and distinct from the risk that the Fund’s NAV may decrease.

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 current valuation of such investments in the event of the need to liquidate such assets.

Interest Rate Risk. In general, the value of debt instruments 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 the time-weighted expected cash flows of a fixed-income security, while maturity refers to the amount of time until a fixed-income security matures. 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. Because the Fund is managed toward an income objective, it may hold more longer duration or maturity obligations and thereby be more exposed to interest rate risk than municipal income funds that are managed with a greater emphasis on total return. The impact of interest rate changes is significantly less for floating-rate instruments that have relatively short periodic rate resets (e.g., ninety days or less). In a rising interest rate environment, the durations or maturities 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 may 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, is expected to cease publishing certain LIBOR settings on December 31, 2021, and the remaining LIBOR settings on June 30, 2023. Although the transition process away from LIBOR is expected to be defined in advance of the anticipated discontinuation, there remains uncertainty regarding the future utilization of LIBOR and the nature of any replacement rate or rates. 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.

Credit Risk. Investments in municipal obligations 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 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. Municipal obligations may be insured as to principal and interest payments. If the claims-paying ability or other rating of the insurer is downgraded by a rating agency, the value of such obligations may be negatively affected.

Municipal Obligations Risk. The amount of public information available about municipal obligations is generally less than for corporate equities or bonds, meaning that the investment performance of municipal obligations may be more dependent on the analytical abilities of the investment adviser than stock or corporate bond investments. The secondary market for municipal obligations also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its municipal obligations at attractive prices. The differences between the price at which an obligation can be purchased and the price at which it can be sold may widen during periods of market distress. Less liquid obligations can become more difficult to value and be subject to erratic price movements. The increased presence of nontraditional participants (such as proprietary trading desks of investment banks and hedge funds) or the absence of traditional participants (such as individuals, insurance companies, banks and life insurance companies) in the municipal markets may lead to greater volatility in the markets because non-traditional participants may trade more frequently or in greater volume.

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.

Leverage Risk. Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an asset, index, rate or instrument. Leverage can also result from borrowings, issuance of preferred shares or participation in residual interest bond transactions. 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 NAV 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 Fund’s portfolio securities. The loss on leveraged investments may substantially exceed the initial investment. The Fund intends to use leverage to provide the holders of common shares with a potentially higher return. To the extent the income derived from securities purchased with funds received from leverage exceeds the cost of leverage, the Fund’s return will be greater than if leverage had not been used. Conversely, if the income from the securities purchased with such funds is not sufficient to cover the cost of leverage, the return to the Fund

will be less than if leverage had not been used, and therefore the amount available for distribution to common shareholders as dividends and other distributions will be reduced. In the latter case, the investment adviser in its best judgment may nevertheless determine to maintain the Fund’s leveraged position if it deems such action to be appropriate. The use of leverage through issuance of preferred shares by the Fund creates an opportunity for increased net income, but, at the same time, creates special risks. There can be no assurance that a leveraging strategy will be successful during any period in which it is employed.

Risk of Residual Interest Bonds. The Fund may enter into residual interest bond transactions, which expose the Fund to leverage and greater risk than an investment in a fixed-rate municipal bond. The interest payments that the Fund receives on the residual interest bonds acquired in such transactions vary inversely with short-term interest rates, normally decreasing when short-term rates increase. The value and market for residual interest bonds are volatile and such bonds may have limited liquidity. As required by applicable accounting standards, the Fund records interest expense on its liability with respect to floating-rate notes and also records offsetting interest income in an amount equal to this expense.

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.

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.

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.

Sector and Geographic Risk. Because the Fund may invest a significant portion of its assets in obligations issued in a particular state and/or U.S. territories and in certain types of municipal or other obligations and/or in certain sectors, the value of Fund shares may be affected by events that adversely affect that state, U.S. territory, sector or type of obligation and may fluctuate more than that of a fund that invests more broadly. General obligation bonds issued by municipalities are adversely affected by economic downturns and any resulting decline in tax revenues. Please refer to the Fund’s Statement of Additional Information for state-specific economic information as well as information about Puerto Rico, the U.S. Virgin Islands, Guam and American Samoa.

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.

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. 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.

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.

Tax Risk. Income from tax-exempt municipal obligations could be declared taxable because of changes in tax laws, adverse interpretations by the relevant taxing authority or the non-compliant conduct of the issuer of an obligation.

Tax-Sensitive Investing Risk. The Fund may hold a security in order to achieve more favorable tax-treatment or to sell a security in order to create tax losses. The Fund’s utilization of various tax-management techniques may be curtailed or eliminated by tax legislation, regulation or interpretations. The Fund may not be able to minimize taxable distributions to shareholders and a portion of the Fund’s distributions may be taxable.

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. In general, cyber incidents can result from deliberate attacks or unintentional events. 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, have the ability to cause disruptions and impact business operations potentially resulting in financial losses, interference with the Fund’s ability to calculate its net asset value, impediments to trading, the inability of Fund shareholders to transact business, violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, reimbursement or other compensation costs, or additional compliance costs.

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. 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.

Eaton Vance California Municipal Bond Fund

Investment Objective and Principal Strategies

The Fund’s investment objective is to provide current income exempt from federal income tax and California State personal income taxes.

During normal market conditions, at least 80% of the Fund’s net assets will be invested in municipal obligations, the interest on which is exempt from federal income tax, including the alternative minimum tax (“AMT”), and California State personal income taxes and that are rated A or better by Moody’s Investors Service, Inc. (“Moody’s”), S&P Global Ratings (“S&P”) or Fitch Ratings (“Fitch”). The foregoing 80% policy may not be changed without shareholder approval. Under normal market conditions, the Fund expects to be fully invested (at least 95% of its net assets) in accordance with its investment objective. The Fund may invest up to 20% of its net assets in municipal obligations rated BBB/Baa or below (or unrated obligations deemed by the Fund’s adviser, Eaton Vance Management (“Eaton Vance”), to be of equivalent quality), provided that not more than 15% of its net assets may be invested in municipal obligations rated below B (or unrated obligations deemed by Eaton Vance to be of equivalent quality) and may invest up to 20% of its net assets in bonds on which the interest is subject to the AMT. When a municipal obligation is split rated (meaning rated in different categories by Moody’s, S&P or Fitch) the Fund will deem the higher rating to apply.

The Fund may purchase derivative instruments, which derive their value from another instrument, security or index, including financial futures contracts and related options, interest rate swaps and forward rate contracts. The Fund also may invest in residual interests of a trust (the “trust”) that holds municipal securities (“RIBs”). The trust will also issue floating-rate notes to third parties that may be senior to a Fund’s residual interest. The Fund may purchase and sell financial futures contracts and related options, including futures contracts and related options based on various debt securities and securities indices, as well as interest rate swaps and forward rate contracts, to seek to hedge against changes in interest rates or for other risk management purposes.

Except for certain fundamental investment restrictions set forth in the Fund’s registration statement and the 80% requirement pertaining to investment in municipal and insured municipal obligations set forth above, the investment objective and policies of the Fund may be changed by the Board without shareholder action.

The Fund employs leverage to seek opportunities for additional income. Leverage may amplify the effect on the Fund’s NAV of any increase or decrease in the value of investments held. The Fund generally will not use leverage if the investment adviser anticipates that it would result in a lower return to shareholders for any significant amount of time. There can be no assurance that the use of leverage will be successful.

Principal Risks

Market Discount Risk. As with any security, the market value of the common shares may increase or decrease from the amount initially paid for the common shares. The Fund’s common shares have traded both at a premium and at a discount relative to NAV. The shares of closed-end management investment companies frequently trade at a discount from their NAV. This is a risk separate and distinct from the risk that the Fund’s NAV may decrease.

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 current valuation of such investments in the event of the need to liquidate such assets.

Interest Rate Risk. In general, the value of debt instruments 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 the time-weighted expected cash flows of a fixed-income security, while maturity refers to the amount of time until a fixed-income security matures. 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. Because the Fund is managed toward an income objective, it may hold more longer duration or maturity obligations and thereby be more exposed to interest rate risk than municipal income funds that are managed with a greater emphasis on total return. The impact of interest rate changes is significantly less for floating-rate instruments that have relatively short periodic rate resets (e.g., ninety days or less). In a rising interest rate environment, the durations or maturities 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 may 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, is expected to cease publishing certain LIBOR settings on December 31, 2021, and the remaining LIBOR settings on June 30, 2023. Although the transition process away from LIBOR is expected to be defined in advance of the anticipated discontinuation, there remains uncertainty regarding the future utilization of LIBOR and the nature of any replacement rate or rates. 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.

Credit Risk. Investments in municipal obligations 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 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. Municipal obligations may be insured as to principal and interest payments. If the claims-paying ability or other rating of the insurer is downgraded by a rating agency, the value of such obligations may be negatively affected.

Municipal Obligations Risk. The amount of public information available about municipal obligations is generally less than for corporate equities or bonds, meaning that the investment performance of municipal obligations may be more dependent on the analytical abilities of the investment adviser than stock or corporate bond investments. The secondary market for municipal obligations also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its municipal obligations at attractive prices. The differences between the price at which an obligation can be purchased and the price at which it can be sold may widen during periods of market distress. Less liquid obligations can become more difficult to value and be subject to erratic price movements. The increased presence of nontraditional participants (such as proprietary trading desks of investment banks and hedge funds) or the absence of traditional participants (such as individuals, insurance companies, banks and life insurance companies) in the municipal markets may lead to greater volatility in the markets because non-traditional participants may trade more frequently or in greater volume.

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.

Leverage Risk. Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an asset, index, rate or instrument. Leverage can also result from borrowings, issuance of preferred shares or participation in residual interest bond transactions. 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 NAV 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 Fund’s portfolio securities. The loss on leveraged investments may substantially exceed the initial investment. The Fund intends to use leverage to provide the holders of common shares with a potentially higher return. To the extent the income derived from securities purchased with funds received from leverage exceeds the cost of

leverage, the Fund’s return will be greater than if leverage had not been used. Conversely, if the income from the securities purchased with such funds is not sufficient to cover the cost of leverage, the return to the Fund will be less than if leverage had not been used, and therefore the amount available for distribution to common shareholders as dividends and other distributions will be reduced. In the latter case, the investment adviser in its best judgment may nevertheless determine to maintain the Fund’s leveraged position if it deems such action to be appropriate. The use of leverage through issuance of preferred shares by the Fund creates an opportunity for increased net income, but, at the same time, creates special risks. There can be no assurance that a leveraging strategy will be successful during any period in which it is employed.

Risk of Residual Interest Bonds. The Fund may enter into residual interest bond transactions, which expose the Fund to leverage and greater risk than an investment in a fixed-rate municipal bond. The interest payments that the Fund receives on the residual interest bonds acquired in such transactions vary inversely with short-term interest rates, normally decreasing when short-term rates increase. The value and market for residual interest bonds are volatile and such bonds may have limited liquidity. As required by applicable accounting standards, the Fund records interest expense on its liability with respect to floating-rate notes and also records offsetting interest income in an amount equal to this expense.

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.

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.

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.

Sector and Geographic Risk. Because the Fund may invest a significant portion of its assets in obligations issued in a particular state and/or U.S. territories and in certain types of municipal or other obligations and/or in certain sectors, the value of Fund shares may be affected by events that adversely affect that state, U.S. territory, sector or type of obligation and may fluctuate more than that of a fund that invests more broadly. General obligation bonds issued by municipalities are adversely affected by economic downturns and any resulting decline in tax revenues. Please refer to the Fund’s Statement of Additional Information for state-specific economic information as well as information about Puerto Rico, the U.S. Virgin Islands, Guam and American Samoa.

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.

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. 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.

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.

Tax Risk. Income from tax-exempt municipal obligations could be declared taxable because of changes in tax laws, adverse interpretations by the relevant taxing authority or the non-compliant conduct of the issuer of an obligation.

Tax-Sensitive Investing Risk. The Fund may hold a security in order to achieve more favorable tax-treatment or to sell a security in order to create tax losses. The Fund’s utilization of various tax-management techniques may be curtailed or eliminated by tax legislation, regulation or interpretations. The Fund may not be able to minimize taxable distributions to shareholders and a portion of the Fund’s distributions may be taxable.

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. In general, cyber incidents can result from deliberate attacks or unintentional events. 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, have the ability to cause disruptions and impact business operations potentially resulting in financial losses, interference with the Fund’s ability to calculate its net asset value, impediments to trading, the inability of Fund shareholders to transact business, violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, reimbursement or other compensation costs, or additional compliance costs.

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. 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.

Eaton Vance New York Municipal Bond Fund

Investment Objective and Principal Strategies

The Fund’s investment objective is to provide current income exempt from federal income tax and New York State and New York City personal income taxes.

During normal market conditions, at least 80% of the Fund’s net assets will be invested in municipal obligations, the interest on which is exempt from federal income tax, including the alternative minimum tax (“AMT”), and New York State and New York City personal income taxes and that are rated A or better by Moody’s Investors Service, Inc. (“Moody’s”), S&P Global Ratings (“S&P”) or Fitch Ratings (“Fitch”). The foregoing 80% policy may not be changed without shareholder approval. Under normal market conditions, the Fund expects to be fully invested (at least 95% of its net assets) in accordance with its investment objective. The Fund may invest up to 20% of its net assets in municipal obligations rated BBB/Baa or below (or unrated obligations deemed by the Fund’s adviser, Eaton Vance Management (“Eaton Vance”), to be of equivalent quality), provided that not more than 15% of its net assets may be invested in municipal obligations rated below B (or unrated obligations deemed by Eaton Vance to be of equivalent quality) and may invest up to 20% of its net assets in bonds on which the interest is subject to the AMT. When a municipal obligation is split rated (meaning rated in different categories by Moody’s, S&P or Fitch) the Fund will deem the higher rating to apply.

The Fund may purchase derivative instruments, which derive their value from another instrument, security or index, including financial futures contracts and related options, interest rate swaps and forward rate contracts. The Fund also may invest in residual interests of a trust (the “trust”) that holds municipal securities (“RIBs”). The trust will also issue floating-rate notes to third parties that may be senior to a Fund’s residual interest. The Fund may purchase and sell financial futures contracts and related options, including futures contracts and related options based on various debt securities and securities indices, as well as interest rate swaps and forward rate contracts, to seek to hedge against changes in interest rates or for other risk management purposes.

Except for certain fundamental investment restrictions set forth in the Fund’s registration statement and the 80% requirement pertaining to investment in municipal and insured municipal obligations set forth above, the investment objective and policies of the Fund may be changed by the Board without shareholder action.

The Fund employs leverage to seek opportunities for additional income. Leverage may amplify the effect on the Fund’s NAV of any increase or decrease in the value of investments held. The Fund generally will not use leverage if the investment adviser anticipates that it would result in a lower return to shareholders for any significant amount of time. There can be no assurance that the use of leverage will be successful.

Principal Risks

Market Discount Risk. As with any security, the market value of the common shares may increase or decrease from the amount initially paid for the common shares. The Fund’s common shares have traded both at a premium and at a discount relative to NAV. The shares of closed-end management investment companies frequently trade at a discount from their NAV. This is a risk separate and distinct from the risk that the Fund’s NAV may decrease.

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 current valuation of such investments in the event of the need to liquidate such assets.

Interest Rate Risk. In general, the value of debt instruments 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 the time-weighted expected cash flows of a fixed-income security, while maturity refers to the amount of time until a fixed-income security matures. 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. Because the Fund is managed toward an income objective, it may hold more longer duration or maturity obligations and thereby be more exposed to interest rate risk than municipal income funds that are managed with a greater emphasis on total return. The impact of interest rate changes is significantly less for floating-rate instruments that have relatively short periodic rate resets (e.g., ninety days or less). In a rising interest rate environment, the durations or maturities 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 may 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, is expected to cease publishing certain LIBOR settings on December 31, 2021, and the remaining LIBOR settings on June 30, 2023. Although the transition process away from LIBOR is expected to be defined in advance of the anticipated discontinuation, there remains uncertainty regarding the future utilization of LIBOR and the nature of any replacement rate or rates. 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.

Credit Risk. Investments in municipal obligations 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 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. Municipal obligations may be insured as to principal and interest payments. If the claims-paying ability or other rating of the insurer is downgraded by a rating agency, the value of such obligations may be negatively affected.

Municipal Obligations Risk. The amount of public information available about municipal obligations is generally less than for corporate equities or bonds, meaning that the investment performance of municipal obligations may be more dependent on the analytical abilities of the investment adviser than stock or corporate bond investments. The secondary market for municipal obligations also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its municipal obligations at attractive prices. The differences between the price at which an obligation can be purchased and the price at which it can be sold may widen during periods of market distress. Less liquid obligations can become more difficult to value and be subject to erratic price movements. The increased presence of nontraditional participants (such as proprietary trading desks of investment banks and hedge funds) or the absence of traditional participants (such as individuals, insurance companies, banks and life insurance companies) in the municipal markets may lead to greater volatility in the markets because non-traditional participants may trade more frequently or in greater volume.

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.

Leverage Risk. Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an asset, index, rate or instrument. Leverage can also result from borrowings, issuance of preferred shares or participation in residual interest bond transactions. 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 NAV 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 Fund’s portfolio securities. The loss on leveraged investments may substantially exceed the initial investment. The Fund intends to use leverage to provide the holders of common shares with a potentially higher return. To the extent the income derived from securities purchased with funds received from leverage exceeds the cost of leverage, the Fund’s return will be greater than if leverage had not been

used. Conversely, if the income from the securities purchased with such funds is not sufficient to cover the cost of leverage, the return to the Fund will be less than if leverage had not been used, and therefore the amount available for distribution to common shareholders as dividends and other distributions will be reduced. In the latter case, the investment adviser in its best judgment may nevertheless determine to maintain the Fund’s leveraged position if it deems such action to be appropriate. The use of leverage through issuance of preferred shares by the Fund creates an opportunity for increased net income, but, at the same time, creates special risks. There can be no assurance that a leveraging strategy will be successful during any period in which it is employed.

Risk of Residual Interest Bonds. The Fund may enter into residual interest bond transactions, which expose the Fund to leverage and greater risk than an investment in a fixed-rate municipal bond. The interest payments that the Fund receives on the residual interest bonds acquired in such transactions vary inversely with short-term interest rates, normally decreasing when short-term rates increase. The value and market for residual interest bonds are volatile and such bonds may have limited liquidity. As required by applicable accounting standards, the Fund records interest expense on its liability with respect to floating-rate notes and also records offsetting interest income in an amount equal to this expense.

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.

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.

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.

Sector and Geographic Risk. Because the Fund may invest a significant portion of its assets in obligations issued in a particular state and/or U.S. territories and in certain types of municipal or other obligations and/or in certain sectors, the value of Fund shares may be affected by events that adversely affect that state, U.S. territory, sector or type of obligation and may fluctuate more than that of a fund that invests more broadly. General obligation bonds issued by municipalities are adversely affected by economic downturns and any resulting decline in tax revenues. Please refer to the Fund’s Statement of Additional Information for state-specific economic information as well as information about Puerto Rico, the U.S. Virgin Islands, Guam and American Samoa.

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.

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. 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.

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.

Tax Risk. Income from tax-exempt municipal obligations could be declared taxable because of changes in tax laws, adverse interpretations by the relevant taxing authority or the non-compliant conduct of the issuer of an obligation.

Tax-Sensitive Investing Risk. The Fund may hold a security in order to achieve more favorable tax-treatment or to sell a security in order to create tax losses. The Fund’s utilization of various tax-management techniques may be curtailed or eliminated by tax legislation, regulation or interpretations. The Fund may not be able to minimize taxable distributions to shareholders and a portion of the Fund’s distributions may be taxable.

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. In general, cyber incidents can result from deliberate attacks or unintentional events. 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, have the ability to cause disruptions and impact business operations potentially resulting in financial losses, interference with the Fund’s ability to calculate its net asset value, impediments to trading, the inability of Fund shareholders to transact business, violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, reimbursement or other compensation costs, or additional compliance costs.

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. 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.

Fund profiles subject to change due to active management.

Additional Information

Yield curve is a graphical representation of the yields offered by bonds of various maturities. The yield curve flattens when long-term interest rates fall and/or short-term interest rates increase, and the yield curve steepens when long-term interest rates increase and/or short-term interest rates fall.

Important Notice to Shareholders

Effective October 1, 2021, Cynthia J. Clemson and Julie P. Callahan are the portfolio managers of the Municipal Bond Fund, Trevor G. Smith is the portfolio manager of the California Municipal Bond Fund, and Christopher J. Eustance is the portfolio manager of the New York Municipal Bond Fund.

Effective August 24, 2021, the Bloomberg Barclays fixed income indices were rebranded as Bloomberg indices.