As filed with the Securities and Exchange Commission on March 28, 2025

Securities Act File No. 333-281390
1940 Act File No. 811-23434

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM N-2

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

[X]

Pre-Effective Amendment No. 3
Post-Effective Amendment No.

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940

[X]

Amendment No. 15

RiverNorth Managed Duration Municipal Income Fund, Inc.
(Exact Name of Registrant as Specified in Charter)

360 South Rosemary Avenue, Suite 1420
West Palm Beach, FL 33401
(Address of Principal Executive Offices)

(561) 484-7185
(Registrant’s Telephone Number)

Marcus L. Collins, Esq.
RiverNorth Capital Management, LLC
360 South Rosemary Avenue, Suite 1420
West Palm Beach, FL 33401
(Name and Address of Agent for Service)

Copy to:
Joshua B. Deringer, Esq.
Faegre Drinker Biddle & Reath LLP
One Logan Square, Ste. 2000
Philadelphia, PA 19103-6996
215-988-2700

APPROXIMATE DATE OF PROPOSED PUBLIC OFFERING:
AS SOON AS PRACTICABLE AFTER THE EFFECTIVE DATE
OF THIS REGISTRATION STATEMENT.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, check the following box [ ]

If any securities being registered on this Form will be offered on a delayed or continuous basis in reliance on Rule 415 under the Securities Act of 1933 (the “Securities Act”), other than securities offered in connection with dividend or interest reinvestment plans, check the following box [X]

If this Form is a registration statement pursuant to General Instruction A.2 or a post-effective amendment thereto, check the following box [X]

If this Form is a registration statement pursuant to General Instruction B or a post-effective amendment thereto that will become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box [ ]

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction B to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box [ ]

It is proposed that this filing will become effective (check appropriate box):

[ ] when declared effective pursuant to section 8(c)

Check each box that appropriately characterizes the Registrant:

[X] Registered Closed-End Fund (closed-end company that is registered under the Investment Company Act of 1940 (the “Investment Company Act”)).

[ ] Business Development Company (closed-end company that intends or has elected to be regulated as a business development company under the Investment Company Act.

[ ] Interval Fund (Registered Closed-End Fund or a Business Development Company that makes periodic repurchase offers under Rule 23c-3 under the Investment Company Act).

[X] A.2 Qualified (qualified to register securities pursuant to General Instruction A.2 of this Form).

[ ] Well-Known Seasoned Issuer (as defined by Rule 405 under the Securities Act).

[ ] Emerging Growth Company (as defined by Rule 12b-2 under the Securities and Exchange Act of 1934).

[ ] If an Emerging Growth Company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.

[ ] New Registrant (registered or regulated under the Investment Company Act for less than 12 calendar months preceding this filing).

THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF THE SECURITIES ACT OF 1933, OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME EFFECTIVE ON SUCH DATE AS THE SECURITIES AND EXCHANGE COMMISSION, ACTING PURSUANT TO SECTION 8(A), MAY DETERMINE

The information in this prospectus is not complete and may be changed. We may not sell these securities 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 is not permitted.

Subject to Completion, Dated March 28, 2025

BASE PROSPECTUS

$400,000,000
RiverNorth Managed Duration Municipal Income Fund, Inc.
Common Stock
Preferred Stock
Subscription Rights for Common Stock
Subscription Rights for Preferred Stock
Subscription Rights for Common and Preferred Stock

The Fund. RiverNorth Managed Duration Municipal Income Fund, Inc. (the “Fund”) is a diversified, closed-end management investment company.

Investment Objectives. The Fund’s primary investment objective is current income exempt from regular U.S. federal income taxes (but which may be includable in taxable income for purposes of the Federal alternative minimum tax). The Fund’s secondary investment objective is total return. There is no assurance that the Fund will achieve its investment objectives.

Principal Investment Strategies. Under normal market conditions, the Fund seeks to achieve its investment objectives by investing, directly or indirectly, at least 80% of its Managed Assets (as defined below) in municipal bonds, the interest on which is, in the opinion of bond counsel to the issuers, generally excludable from gross income for regular U.S. federal income tax purposes, except that the interest may be includable in taxable income for purposes of the Federal alternative minimum tax (“Municipal Bonds”). In order to qualify to pay exempt-interest dividends, which are items of interest excludable from gross income for federal income tax purposes, the Fund seeks to invest at least 50% of its Managed Assets either directly (and indirectly through tender option bond transactions) in such Municipal Bonds or in other funds that are taxed as regulated investment companies. In addition, under normal market conditions, the Fund will seek to maintain Managed Assets with a weighted average effective duration that is within three years of the weighted average effective duration of the Bloomberg U.S. Municipal Bond Index. See “Investment Objectives, Strategies and Policies-Principal Investment Strategies-Managed Duration Strategy.”

The Fund seeks to allocate its assets among the two principal investment strategies described below:

Tactical Municipal Closed-End Fund Strategy (25% - 50% of Managed Assets): This strategy seeks to (i) generate returns through investments in closed-end funds, exchange-traded funds and other investment companies (collectively, the “Underlying Funds”) that invest, under normal market conditions, at least 80% of their net assets, plus the amount of any borrowings for investment purposes, in Municipal Bonds, and (ii) derive value from the discount and premium spreads associated with closed-end funds that invest, under normal market conditions, at least 80% of their net assets, plus the amount of any borrowings for investment purposes, in Municipal Bonds. The term “tactical” is used to indicate that this strategy seeks to take advantage of pricing discrepancies in the closed-end fund market (e.g., the difference between a closed-end fund’s market value and its net asset value (“NAV”)).

Municipal Bond Income Strategy (50% - 75% of Managed Assets): This strategy seeks to capitalize on inefficiencies in the tax-exempt and tax-advantaged securities markets through investments in Municipal Bonds. The Fund may not directly invest more than 25% of the Managed Assets allocated to this strategy in Municipal Bonds in any one industry or in any one state of origin, and the Fund may not directly invest more than 5% of the Managed Assets allocated to this strategy in the Municipal Bonds of any one issuer, except that the foregoing industry and issuer restrictions shall not apply to general obligation bonds and the Fund will consider the obligor or borrower underlying the Municipal Bond to be the “issuer.” The Fund may invest up to 30% of the Managed Assets allocated to this strategy in Municipal Bonds that pay interest that may be includable in taxable income for purposes of the Federal alternative minimum tax. The Fund can invest, directly or indirectly through Underlying Funds, in bonds of any maturity; however, under this strategy, it will generally invest in Municipal Bonds that have a maturity of five years or longer at the time of purchase.

The Fund may offer, from time to time, up to $400,000,000 aggregate initial offering price of (i) shares of its common stock, $0.0001 par value per share (“Common Shares”), (ii) shares of its preferred stock (“Preferred Shares”) and/or (iii) subscription rights to purchase Common Shares, Preferred Shares or both (“Rights” and together with the Common Shares and Preferred Shares, “Securities”), in one or more offerings in amounts, at prices and on terms set forth in a supplement to this Prospectus. See “Description of the Fund’s Securities” beginning on page 35.

The Fund may offer Securities directly to one or more purchasers, including existing common shareholders and/or preferred shareholders in a Rights offering, through agents that the Fund or the purchasers designate from time to time, or to or through underwriters or dealers. The prospectus supplement relating to the particular offering will identify any agents or underwriters involved in the sale of the Fund’s Securities, and will set forth any applicable purchase price, fee, commission or discount arrangement between the Fund and such agents or underwriters or among the underwriters or the basis upon which such amount may be calculated. The prospectus supplement relating to any sale of preferred stock will set forth the liquidation preference and information about the dividend period, dividend rate, any call protection or non-call period and other matters, including the terms, if any, on which the preferred stock may be exchanged for or converted into shares of common stock or any other security and, if applicable, the conversion or exchange price, or how it will be calculated, and the conversion or exchange period. A supplement to this Prospectus relating to any offering of subscription rights will set forth the number of shares (common or preferred) issuable upon the exercise of each right and the other terms of such rights offering, including whether the Preferred Shares issuable upon the exercise of such rights are convertible into Common Shares. The Fund may not sell Securities through agents, underwriters or dealers without delivery of this Prospectus and a prospectus supplement. For more information about the manner in which the Fund may offer shares of its common stock, see “Plan of Distribution.”

The currently outstanding shares of the Fund’s common stock are, and the shares of the Fund’s common stock offered in this Prospectus will be, subject to notice of issuance, listed on the New York Stock Exchange (“NYSE”) under the trading or “ticker” symbol “RMM.” The NAV of the Fund's common stock on March 11, 2025 was $15.93 per share, and the last sale price of the Fund's common stock on the NYSE on such date was $14.57. Shares of common stock of closed-end funds, like the Fund, frequently trade at discounts to their NAVs. If the shares of the Fund’s common stock trade at a discount to NAVs, the risk of loss may increase for purchasers in an offering under this Prospectus, especially for those investors who expect to sell their shares in a relatively short period after purchasing shares in such an offering. Following a Rights offering, a shareholder may experience dilution in NAV per share of stock if the subscription price per share is below the NAV per share on the expiration date.

The applicable prospectus supplement will set forth whether or not the Preferred Shares offered in this Prospectus will be listed or traded on any securities exchange. If the Fund’s Preferred Shares are not listed on a securities exchange, there may be no active secondary trading market for such shares and an investment in such shares may be illiquid.

The Fund, or the Underlying Funds in which the Fund invests, may invest in securities of any credit quality, including, without limit, securities that are rated below investment grade, except that, under normal market conditions, at least 50% of the Fund’s Managed Assets is directly or indirectly invested in investment grade Municipal Bonds. Also, under normal market conditions, the Fund invests at least 65% of the Fund’s Managed Assets allocated to the Municipal Bond Income Strategy directly in investment grade Municipal Bonds and invests no more than 20% of the Fund’s Managed Assets allocated to the Municipal Bond Income Strategy in Municipal Bonds rated at or below Caa1 by Moody’s Investor Services, Inc. (“Moody’s”) or CCC+ by S&P Global Ratings (“S&P”) or Fitch Ratings, a part of the Fitch Group, or comparably rated by another nationally recognized statistical rating organization (“NRSRO”) or, if unrated, determined by the Adviser or Subadviser to be of comparable credit quality. Below investment grade securities are commonly referred to as “junk” and “high yield” securities and are considered speculative with respect to the issuer’s capacity to pay interest and repay principal. Subject to the foregoing limitations, the Fund (and the Underlying Funds in which the Fund invests) may invest in securities receiving the lowest ratings from the NRSROs, including securities rated C by Moody’s or D- by S&P, which indicates that the security is in default or has little prospect for full recovery of principal or interest. See “Risks-Investment-Related Risks-Credit and Below Investment Grade Securities Risks.”

“Managed Assets” means the total assets of the Fund, including assets attributable to leverage, minus liabilities (other than debt representing leverage and any preferred stock that may be outstanding). Such assets attributable to leverage include the portion of assets in tender option bond trusts of which the Fund owns TOB Residuals (as defined below) that has been effectively financed by the trust’s issuance of TOB Floaters (as defined below). See “Use of Leverage.”

Investment Adviser and Subadviser. The Fund’s investment adviser is RiverNorth Capital Management, LLC (the “Adviser”) and the Fund’s subadviser is MacKay Shields LLC (the “Subadviser”). The Adviser is responsible for the day-to-day management of the Fund’s Managed Assets allocated to the Tactical Municipal Closed-End Fund Strategy. The Subadviser is responsible for the day-to-day management of the Fund’s Managed Assets allocated to the Municipal Bond Income Strategy. See “Management of the Fund.”

Limited Term and Eligible Tender Offer. The Fund will terminate on or before July 25, 2031 (the “Termination Date”); provided, that if the Board of Directors of the Fund (the “Board of Directors”) believes that, under then-current market conditions, it is in the best interests of the Fund to do so, the Fund may extend the Termination Date: (i) once for up to one year (i.e., up to July 25, 2032), and (ii) once for up to an additional six months (i.e., up to January 25, 2033), in each case upon the affirmative vote of a majority of the Board of Directors and without the approval of the holders of the Common Shares of the Fund (the “Common Shareholders”).

In addition, as of a date within twelve months preceding the Termination Date, the Board of Directors may cause the Fund to conduct a tender offer to all Common Shareholders to purchase Common Shares of the Fund at a price equal to the NAV per Common Share on the expiration date of the tender offer (an “Eligible Tender Offer”). The Board of Directors has established that, following an Eligible Tender Offer, the Fund must have at least $100 million of net assets to ensure the continued viability of the Fund (the “Termination Threshold”). In an Eligible Tender Offer, the Fund will offer to purchase all Common Shares held by each Common Shareholder; provided, that if the number of properly tendered Common Shares would result in the Fund’s net assets totaling less than the Termination Threshold, the Eligible Tender Offer will be terminated and no Common Shares will be repurchased pursuant to the Eligible Tender Offer. Instead, the Fund will begin (or continue) liquidating its portfolio and proceed to terminate on or before the Termination Date. The Adviser will pay all costs and expenses associated with the making of an Eligible Tender Offer, other than brokerage and related transaction costs associated with the disposition of portfolio investments in connection with the Eligible Tender Offer, which will be borne by the Fund and its Common Shareholders. An Eligible Tender Offer would be made, and Common Shareholders would be notified thereof, in accordance with the requirements of the Investment Company Act of 1940, as amended (the “1940 Act”), the Securities Exchange Act of 1934 (the “Exchange Act”) and the applicable tender offer rules thereunder (including Rule 13e-4 and Regulation 14E under the Exchange Act). If the number of properly tendered Common Shares would result in the Fund’s net assets equaling or totaling greater than the Termination Threshold, all Common Shares properly tendered and not withdrawn will be purchased by the Fund pursuant to the terms of the Eligible Tender Offer. In addition, the Fund would continue to be subject to its obligations with respect to its issued and outstanding preferred stock or debt securities, if any. See “Risks-Structural Risks-Limited Term and Eligible Tender Offer Risk.”

Following the completion of an Eligible Tender Offer, the Board of Directors may eliminate the limited term structure of the Fund upon the affirmative vote of a majority of the Board of Directors and without the approval of Common Shareholders. In making a decision to do so to provide for the Fund’s perpetual existence, the Board of Directors will take such actions with respect to the continued operations of the Fund as it deems to be in the best interests of the Fund, based on market conditions at such time, the extent of Common Shareholder participation in the Eligible Tender Offer and all other factors deemed relevant by the Board of Directors in consultation with the Adviser and Subadviser, taking into account that the Adviser and Subadviser may have a potential conflict of interest in seeking to convert to a perpetual fund.

The Fund is not a so called “target date” or “life cycle” fund whose asset allocation becomes more conservative over time as its target date, often associated with retirement, approaches. In addition, the Fund is not a “target term” fund whose investment objective is to return its original NAV on the termination date. See “Limited Term and Eligible Tender Offer” and “Risks-Structural Risks-Limited Term and Eligible Tender Offer Risk” below.

Dividends and Distributions. The Fund has implemented a level distribution policy. Under the level distribution policy, the Fund intends to distribute to holders of the Common Shares regular monthly cash distributions of all or a portion of its net investment income. There is no assurance the Fund will make regular monthly distributions or that it will do so at a particular rate. See “Dividends and Distributions.” If the Fund’s investments do not generate sufficient income, the Fund may be required to liquidate a portion of its portfolio to fund these distributions, and therefore the payments may represent a reduction of a shareholder’s principal investment.

From time to time, portions of the Fund’s distributions may constitute a return of capital. A return of capital would reduce a Common Shareholder’s tax basis in its Common Shares, which could result in higher taxes when the Common Shareholder sells such Common Shares. This may cause the Common Shareholder to owe taxes even if it sells Common Shares for less than the original purchase price of such Common Shares. See “Dividends and Distributions.”

Leverage. The Fund may borrow money and/or issue preferred stock, notes or debt securities for investment purposes. These practices are known as leveraging. In addition, the Fund may enter into derivative and other transactions that have the effect of leverage. Such other transactions may include tender option bond transactions (as described herein). As of the time immediately after it enters into any of the foregoing transactions, the Fund will seek to limit its overall effective leverage to 45% of its Managed Assets. The Fund currently anticipates that leverage will be obtained through borrowings from banks or other financial institutions and the use of proceeds received from tender option bond transactions. See “Use of Leverage - Tender Option Bonds.” Since the holders of common stock pay all expenses related to the use of leverage, such use of leverage would create a greater risk of loss for the Fund’s Common Shares than if leverage is not used. See "Use of Leverage."

The Prospectus sets forth concisely the information about the Fund and the Securities that a prospective investor ought to know before investing in the Fund. You should read this Prospectus and the related prospectus supplement, which contain important information about the Fund, before deciding whether to invest in the Fund’s Securities, and retain them for future reference. A Statement of Additional Information, dated [ ] (the “SAI”), containing additional information about the Fund, has been filed with the Securities and Exchange Commission (the “SEC”) and is incorporated by reference in its entirety into this Prospectus. You may request a free copy of the Prospectus, the SAI, annual and semi-annual reports to shareholders and other information about the Fund, or make shareholder inquiries, by calling (844) 569-4750, by writing to the Fund at 360 South Rosemary Avenue, Suite 1420, West Palm Beach, FL 33401, or by visiting the Fund’s and the Adviser’s website at rivernorth.com (information included on the website does not form a part of this Prospectus), or from the SEC’s website at sec.gov.

Investing in the Fund involves certain risks. See “Risks” beginning on page 29 of this Prospectus.

Neither the SEC nor any state securities commission has approved or disapproved these securities or determined if this Prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The Fund’s Securities do not represent a deposit or obligation of, and are not guaranteed or endorsed by, any bank or other insured depository institution, and are not federally insured by the Federal Deposit Insurance Corporation, the Federal Reserve Board or any other government agency.

Prospectus dated [ ]

TABLE OF CONTENTS

	Page
PROSPECTUS SUMMARY	7
SUMMARY OF FUND EXPENSES	25
FINANCIAL HIGHLIGHTS	27
SENIOR SECURITIES	27
MARKET AND NET ASSET VALUE INFORMATION	28
THE FUND	30
THE OFFERING	30
USE OF PROCEEDS	31
INVESTMENT OBJECTIVES, STRATEGIES AND POLICIES	31
INVESTMENT PHILOSOPHY AND PROCESS	31
USE OF LEVERAGE	33
RISKS	36
MANAGEMENT OF THE FUND	36
NET ASSET VALUE	40
DIVIDENDS AND DISTRIBUTIONS	41
DIVIDEND REINVESTMENT PLAN	42
DESCRIPTION OF THE FUND’S SECURITIES	42
CERTAIN PROVISIONS OF THE FUND’S CHARTER AND BYLAWS AND OF MARYLAND LAW	46
REPURCHASE OF SHARES	53
RIGHTS OFFERINGS	54
CONVERSION TO OPEN-END FUND	54
LIMITED TERM AND ELIGIBLE TENDER OFFER	55
U.S. FEDERAL INCOME TAX MATTERS	57
CALIFORNIA TAX MATTERS	61
PLAN OF DISTRIBUTION	62
ADMINISTRATOR, FUND ACCOUNTANT, TRANSFER AGENT, DIVIDEND DISBURSING AGENT AND CUSTODIAN	65
LEGAL MATTERS	65
CONTROL PERSONS	66
ADDITIONAL INFORMATION	66
THE FUND’S PRIVACY POLICY	66
INCORPORATION BY REFERENCE	67

You should rely only on the information contained or incorporated by reference in this Prospectus and any related prospectus supplement. The Fund has not authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. The Fund is not making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should not assume that the information provided by this Prospectus and any related prospectus supplement is accurate as of any date other than the respective dates on the front covers. The Fund’s business, financial condition and results of operations may have changed since that date.

PROSPECTUS SUMMARY

This is only a summary of information contained elsewhere in this Prospectus. This summary does not contain all of the information that you should consider before investing in the Fund’s securities (“Securities”) offered by this Prospectus. You should review the more detailed information contained in this Prospectus, and any related prospectus supplement and the Statement of Additional Information (“SAI”), including the documents incorporated by reference. In particular, you should carefully read the section entitled “Risks” in this Prospectus.

The Fund

RiverNorth Managed Duration Municipal Income Fund, Inc. (the “Fund”) is a Maryland corporation registered as a diversified, closed-end management investment company under the Investment Company Act of 1940, as amended (the “1940 Act”). The Fund will have a limited term unless otherwise determined by the Fund’s Board of Directors (“Board of Directors”). See “Limited Term” and “Risks-Structural Risks-Limited Term and Eligible Tender Offer Risk.”

The Fund commenced operations and completed its initial public offering of common stock in July 2019, raising approximately $394,784,940 in equity after payment of offering expenses (and including the exercise of the overallotment option). As of March 11, 2025, the Fund had 19,739,628 shares of its common stock outstanding and net assets applicable to such shares of $314,441,949. The shares of the Fund’s common stock offered by this Prospectus are called “Common Shares” and the holders of Common Shares are called “Common Shareholders.” As used hereinafter in this Prospectus, unless the context otherwise requires, “common shares” refers to the shares of the Fund’s common stock currently outstanding as well as those Common Shares offered by this Prospectus and the holders of common shares are called “common shareholders.” As of the date of this Prospectus, the Fund had not issued any shares of preferred stock (“Preferred Shares”). An investment in the Fund may not be appropriate for all investors.

Investment Adviser and Subadviser

The Fund’s investment adviser is RiverNorth Capital Management, LLC (the “Adviser”) and the Fund’s subadviser is MacKay Shields LLC (the “Subadviser”). The Adviser is responsible for the day-to-day management of the Fund’s Managed Assets (as defined below) allocated to the Tactical Municipal Closed-End Fund Strategy (as described below). The Subadviser is responsible for the day-to-day management of the Fund’s Managed Assets allocated to the Municipal Bond Income Strategy (as described below). Subject to the ranges noted below under “-Principal Investment Strategies and Policies-Tactical Municipal Closed-End Fund Strategy” and “-Principal Investment Strategies and Policies-Municipal Bond Income Strategy,” the Adviser determines the portion of the Fund’s Managed Assets to allocate to each strategy and may, from time to time, adjust the allocations. See “Management of the Fund.”

The Offering

The Fund may offer Securities directly to one or more purchasers, including existing common shareholders and/or preferred shareholders in a Rights offering, through agents that the Fund or the purchasers designate from time to time, or to or through underwriters or dealers. The prospectus supplement relating to the offering will identify any agents or underwriters involved in the sale of the Securities, and will set forth any applicable purchase price, fee, commission or discount arrangement between the Fund and such agents or underwriters or among underwriters or the basis upon which such amount may be calculated. The prospectus supplement relating to any sale of preferred stock will set forth the liquidation preference and information about the dividend period, dividend rate, any call protection or non-call period and other matters, including the terms, if any, on which the preferred stock may be exchanged for or converted into shares of common stock or any other security and, if applicable, the conversion or exchange price, or how it will be calculated, and the conversion or exchange period. A supplement to this Prospectus relating to any offering of subscription rights will set forth the number of shares (common or preferred) issuable upon the exercise of each right and the other terms of such rights offering, including whether the Preferred Shares issuable upon the exercise of such right are convertible into Common Shares. The Fund may not sell Securities through agents, underwriters or dealers without delivery of this Prospectus and a prospectus supplement describing the method and terms of the offering of the Securities. See “Plan of Distribution.”

Offerings of Shares will be subject to the provisions of the 1940 Act, which generally require that the public offering price of common shares of a closed-end investment company (exclusive of distribution commissions and discounts) must equal the net asset value (“NAV”) per share of the company’s common stock (calculated within 48 hours of pricing), absent shareholder approval or under certain other circumstances. The Fund may, however, issue Common Shares pursuant to exercises of Rights at prices below NAV.

Investment Objectives	The Fund’s primary investment objective is current income exempt from regular U.S. federal income taxes (but which may be includable in taxable income for purposes of the Federal alternative minimum tax). The Fund’s secondary investment objective is total return. There is no assurance that the Fund will achieve its investment objectives.
Principal Investment Strategies and Policies	Under normal market conditions, the Fund seeks to achieve its investment objectives by investing, directly or indirectly, at least 80% of its Managed Assets in municipal bonds, the interest on which is, in the opinion of bond counsel to the issuers, generally excludable from gross income for regular U.S. federal income tax purposes, except that the interest may be includable in taxable income for purposes of the Federal alternative minimum tax (“Municipal Bonds”). In order to qualify to pay exempt-interest dividends, which are items of interest excludable from gross income for federal income tax purposes, the Fund seeks to invest at least 50% of its Managed Assets either directly (and indirectly through tender option bond transactions) in such Municipal Bonds or in other funds that are taxed as regulated investment companies. See “Risks-Investment-Related Risks-Tax Risks.” In addition, under normal market conditions, the Fund seeks to maintain Managed Assets with a weighted average effective duration that is within three years of the weighted average effective duration of the Bloomberg U.S. Municipal Bond Index. See “-Managed Duration Strategy” below.

	Municipal Bonds are debt obligations, which may have a variety of issuers, including governmental entities or other qualifying issuers. Issuers may be states, territories and possessions of the United States and the District of Columbia and their political subdivisions, agencies and instrumentalities. Such territories of the United States include Puerto Rico. See “Risks-Investment-Related Risks-Puerto Rico Municipal Bond Risks” for a discussion of the risks associated with an investment in Puerto Rico Municipal Bonds. Municipal Bonds include, among other instruments, general obligation bonds, revenue bonds, municipal leases, certificates of participation, private activity bonds, moral obligation bonds, and tobacco settlement bonds, as well as short-term, tax-exempt obligations such as municipal notes and variable rate demand obligations. See “Investment Objectives, Strategies and Policies” for a description of the types of Municipal Bonds in which the Fund may invest.

The Fund seeks to allocate its assets among the two principal strategies described below. The Adviser determines the portion of the Fund’s Managed Assets to allocate to each strategy and may, from time to time, adjust the allocations. See “Risks-Structural Risks-Asset Allocation Risk.” Under normal market conditions, the Fund may allocate between 25% and 50% of its Managed Assets to the Tactical Municipal Closed-End Fund Strategy and 50% to 75% of its Managed Assets to the Municipal Bond Income Strategy.

Tactical Municipal Closed-End Fund Strategy (25%-50% of Managed Assets). This strategy seeks to (i) generate returns through investments in closed-end funds (“CEFs”), exchange-traded funds (“ETFs”) and other investment companies (collectively, the “Underlying Funds”) that invest, under normal market conditions, at least 80% of their net assets, plus the amount of any borrowings for investment purposes, in Municipal Bonds, and (ii) derive value from the discount and premium spreads associated with CEFs that invest, under normal market conditions, at least 80% of their net assets, plus the amount of any borrowings for investment purposes, in Municipal Bonds. See “Risks-Investment-Related Risks-Tactical Municipal Closed-End Fund Strategy Risk.” All Underlying Funds will be registered under the Securities Act of 1933, as amended (the “Securities Act”).

Under normal market conditions, the Fund limits its investments in CEFs that have been in operation for less than one year to no more than 10% of the Fund’s Managed Assets allocated to the Tactical Municipal Closed-End Fund Strategy. The Fund will not invest in inverse ETFs or leveraged ETFs. Under normal market conditions, the Fund may not invest more than 20% of its Managed Assets in the Tactical Municipal Closed-End Fund Strategy in single state municipal CEFs. The Fund’s shareholders will indirectly bear the expenses, including the management fees, of the Underlying Funds. See “Risks-Investment-Related Risks-Underlying Fund Risks.”

Under Section 12(d)(1)(A) of the 1940 Act, the Fund may hold securities of an Underlying Fund in amounts which (i) do not exceed 3% of the total outstanding voting stock of the Underlying Fund, (ii) do not exceed 5% of the value of the Fund’s total assets and (iii) when added to all other Underlying Fund securities held by the Fund, do not exceed 10% of the value of the Fund’s total assets. These limits may be exceeded when permitted under Rule 12d1-4. The Fund intends to rely on either Section 12(d)(1)(F) of the 1940 Act, which provides that the provisions of Section 12(d)(1)(A) shall not apply to securities purchased or otherwise acquired by the Fund if (i) immediately after such purchase or acquisition not more than 3% of the total outstanding stock of such Underlying Fund is owned by the Fund and all affiliated persons of the Fund, and (ii) certain requirements are met with respect to sales charges, or Rule 12d1-4.

The Fund may invest in Underlying Funds that invest in securities that are rated below investment grade, including those receiving the lowest ratings from S&P Global Ratings (“S&P”), Fitch Ratings, a part of the Fitch Group (“Fitch”), or Moody’s Investor Services, Inc. (“Moody’s”), or comparably rated by another nationally recognized statistical rating organization (“NRSRO”) or, if unrated, determined by the Adviser or Subadviser to be of comparable credit quality, which indicates that the security is in default or has little prospect for full recovery of principal or interest. See “Risks-Investment-Related Risks-Defaulted and Distressed Securities Risk.” Below investment grade securities (such as securities rated below BBB- by S&P or Fitch or below Baa3 by Moody’s) are commonly referred to as “junk” and “high yield” securities. Below investment grade securities are considered speculative with respect to the issuer’s capacity to pay interest and repay principal. The Underlying Funds in which the Fund invests may invest in securities receiving the lowest ratings from the NRSROs, including securities rated C by Moody’s or D- by S&P. Lower rated below investment grade securities are considered more vulnerable to nonpayment than other below investment grade securities and their issuers are more dependent on favorable business, financial and economic conditions to meet their financial commitments. The lowest rated below investment grade securities are typically already in default. See “Risks-Investment-Related Risks-Credit and Below Investment Grade Securities Risks.”

The Underlying Funds in which the Fund invests will not include those that are advised or subadvised by the Adviser, the Subadviser or their affiliates.

Municipal Bond Income Strategy (50%-75% of Managed Assets). This strategy seeks to capitalize on inefficiencies in the tax-exempt and tax-advantaged securities markets through investments in Municipal Bonds. The Fund may not directly invest more than 25% of the Managed Assets allocated to the Municipal Bond Income Strategy in Municipal Bonds in any one industry or in any one state of origin, and the Fund may not directly invest more than 5% of the Managed Assets allocated to this strategy in the Municipal Bonds of any one issuer, except that the foregoing industry and issuer restrictions shall not apply to general obligation bonds and the Fund will consider the obligor or borrower underlying the Municipal Bond to be the “issuer.” See “Risks-Investment-Related Risks-State Specific and Industry Risks.” The Fund may invest up to 30% of the Managed Assets allocated to the Municipal Bond Income Strategy in Municipal Bonds that pay interest that may be includable in taxable income for purposes of the Federal alternative minimum tax. The Fund can invest, directly or indirectly through Underlying Funds, in bonds of any maturity; however, under this strategy, it will generally invest in Municipal Bonds that have a maturity of five years or longer at the time of purchase.

Under normal market conditions, the Fund invests at least 65% of the Fund’s Managed Assets allocated to the Municipal Bond Income Strategy directly in investment grade Municipal Bonds. The Subadviser invests no more than 20% of the Managed Assets allocated to the Municipal Bond Income Strategy in Municipal Bonds rated at or below Caa1 by Moody’s or CCC+ by S&P or Fitch, or comparably rated by another NRSRO, including unrated bonds judged to be of equivalent quality as determined by the Adviser or Subadviser, as applicable. Investment grade securities are those rated Baa or higher by Moody’s (although Moody’s considers securities rated Baa to have speculative characteristics) or BBB or higher by S&P or rated similarly by another NRSRO or, if unrated, judged to be of equivalent quality as determined by the Adviser or Subadviser, as applicable. If the independent ratings agencies assign different ratings to the same security, the Fund will use the higher rating for purposes of determining the security’s credit quality. Subject to the foregoing limitations, the Fund may invest in securities receiving the lowest ratings from the NRSROs, including securities rated C by Moody’s or D- by S&P, which indicates that the security is in default or has little prospect for full recovery of principal or interest. See “Risks-Investment-Related Risks-Credit and Below Investment Grade Securities Risks.”

Under normal market conditions, the Fund, or the Underlying Funds in which the Fund invests, invests at least 50% of its Managed Assets, directly or indirectly in investment grade Municipal Bonds.

Managed Duration Strategy. The Adviser and the Subadviser may use various techniques to manage the duration of the Fund’s portfolio in an attempt to mitigate the risks associated with changes in interest rates. Under normal market conditions, the Fund seeks to maintain Managed Assets with a weighted average effective duration (excluding effects of leverage) that targets the weighted average effective duration of the Bloomberg U.S. Municipal Bond Index, a widely recognized municipal bond index (the “Index”), primarily through its investments in Municipal Bonds and Underlying Funds as well as through short positions in U.S. Treasury futures contracts (as discussed below). As a result of, among other things, changing market conditions and differences between the Fund’s portfolio and the Index, the Fund believes it will generally be able to maintain a weighted average effective duration that is within three years of the weighted average effective duration of the Index. However, under certain market conditions and from time to time for the reasons described below, the Fund’s duration may be outside of such range. In addition, if the effect of the Fund’s use of leverage was included in calculating duration, it could result in a longer duration for the Fund. As of December 31, 2024, the Index had a weighted average effective duration of 6.21 years. The Fund may invest in bonds of any maturity, whether directly through Municipal Bonds or indirectly through Underlying Funds.

Effective duration is a mathematical calculation of the sensitivity of the price of a bond to changes in interest rates, measuring a bond’s expected life on a present value basis, taking into account the bond’s yield, interest payments, final maturity and, in the case of a bond with an embedded option (e.g., the right of the issuer to call the bond prior to maturity, or a sinking fund schedule), the probability that the option will be exercised. The longer the effective duration of a bond or a group of bonds, the more sensitive the bond or group of bonds is to changes in interest rates; the shorter the duration, the less sensitive the bond or group of bonds is to such changes. In general, each year of duration represents an expected 1% change in the value of a bond for every 1% immediate change in interest rates. For example, if the Fund’s portfolio has an average effective duration of five years, its value would be expected to fall by approximately 5% if interest rates rise by 1%. Conversely, the portfolio’s value would be expected to rise about 5% if interest rates fell by 1%.

The Adviser and the Subadviser invest with a view to managing the duration of the Fund. However, the calculation of the Fund’s weighted average effective duration will be contingent upon the Adviser’s ability to adequately determine the weighted average effective duration of each of the Underlying Funds in which it invests, which will inherently be limited as the Adviser’s determination will primarily depend on reporting by such Underlying Funds. Such Underlying Fund reporting will likely be on a delayed basis and could be subject to incomplete or inaccurate information that may not be readily apparent to the Adviser. As a result, the Fund cannot guarantee the precise overall weighted average effective duration of its portfolio at any given point in time and this limitation could cause the Fund’s weighted average effective duration to be outside of its targeted duration range. In addition, the Adviser and Subadviser may use short sales and derivatives such as options, futures contracts, options on futures contracts, and swaps (collectively, “Hedging Positions”) to manage the duration of the Fund. See “Risks-Investment-Related Risks-Derivatives Risks” and “Risks-Investment-Related Risks-Options and Futures Risks.”

A short sale is a transaction in which the Fund sells a security that it does not own in anticipation of a decline in the market price of the security. The Fund may benefit from a short position when the shorted security decreases in value. The Fund anticipates using short positions primarily on U.S. Treasury futures contracts. The Fund will not engage in any short sales of securities issued by CEFs. See “Investment Objectives, Strategies and Policies-Principal Investment Strategies-Other Investments” and “Risks-Investment-Related Risks-Short Sale Risks.”

Other Investments. The Fund may invest, directly or indirectly, up to 20% of its Managed Assets in taxable municipal securities. Any portion of the Fund’s assets invested in taxable municipal securities does not count toward the 50%-75% of the Fund’s assets allocated to Municipal Bonds.

The Fund also may attempt to enhance the return on the cash portion of its portfolio by investing in total return swap agreements and municipal market data rate locks. A total return swap agreement provides the Fund with a return based on the performance of an underlying asset, in exchange for fee payments to a counterparty based on a specific rate. The difference in the value of these income streams is recorded daily by the Fund, and is typically settled in cash at least monthly. If the underlying asset declines in value over the term of the swap, the Fund would be required to pay the dollar value of that decline plus any applicable fees to the counterparty. The Fund may use its own NAV or any other reference asset that the Adviser or Subadviser chooses as the underlying asset in a total return swap. The Fund limits the notional amount of all total return swaps in the aggregate to 15% of the Fund’s Managed Assets. See “Investment Objectives, Strategies and Policies-Principal Investment Strategies-Other Investments” and “Risks-Investment-Related Risks-Swap Risks.”

The Fund may also purchase and sell municipal market data rate locks (“MMD Rate Locks”). An MMD Rate Lock permits the Fund to lock in a specified municipal interest rate for a portion of its portfolio to preserve a return on a particular investment or a portion of its portfolio as a duration management technique or to protect against any increase in the price of securities to be purchased at a later date. By using an MMD Rate Lock, the Fund can create a synthetic long or short position, allowing the Fund to select what the manager believes is an attractive part of the yield curve. The Fund will ordinarily use these transactions as a hedge or for duration or risk management although it is permitted to enter into them to enhance income or gain or to increase the Fund's yield, for example, during periods of steep interest rate yield curves (i.e., wide differences between short term and long term interest rates). An MMD Rate Lock is a contract between the Fund and an MMD Rate Lock provider pursuant to which the parties agree to make payments to each other on a notional amount, contingent upon whether the Municipal Market Data AAA General Obligation Scale is above or below a specified level on the expiration date of the contract. For example, if the Fund buys an MMD Rate Lock and the Municipal Market Data AAA General Obligation Scale is below the specified level on the expiration date, the counterparty to the contract will make a payment to the Fund equal to the specified level minus the actual level, multiplied by the notional amount of the contract. If the Municipal Market Data AAA General Obligation Scale is above the specified level on the expiration date, the Fund will make a payment to the counterparty equal to the actual level minus the specified level, multiplied by the notional amount of the contract.

In addition to the foregoing principal investment strategies of the Fund, the Adviser also may allocate the Fund’s Managed Assets among cash and short-term investments. See “Investment Policies and Techniques-Temporary Investments and Defensive Position” in the SAI. There are no limits on the Fund’s portfolio turnover, and the Fund may buy and sell securities to take advantage of potential short-term trading opportunities without regard to length of time and when the Adviser or Subadviser believes investment considerations warrant such action. High portfolio turnover may result in the realization of net short-term capital gains by the Fund which, when distributed to Common Shareholders, will be taxable as ordinary income. In addition, a higher portfolio turnover rate results in correspondingly greater brokerage commissions and other transactional expenses that are borne by the Fund. See “Risks-Structural Risks-Portfolio Turnover Risk.”

All percentage limitations described in this Prospectus are measured at the time of investment and may be exceeded on a going-forward basis as a result of credit rating downgrades or market value fluctuations of the Fund’s portfolio securities. Unless otherwise specified herein, the Fund may count its holdings in Underlying Funds towards various guideline tests, including the 80% policy so long as the earnings on the underlying holdings of such Underlying Funds are exempt from regular U.S. federal income taxes (but which may be includable in taxable income for purposes of the Federal alternative minimum tax).

Unless otherwise specified, the investment policies and limitations of the Fund are not considered to be fundamental by the Fund and can be changed without a vote of the holders of the Common Shares (the “Common Shareholders”). The Fund’s primary investment objective, 80% policy and certain investment restrictions specifically identified as such in the SAI are considered fundamental and may not be changed without the approval of the holders of a majority of the outstanding voting securities of the Fund, as defined in the 1940 Act, which includes Common Shares and Preferred Shares, if any, voting together as a single class, and the holders of the outstanding Preferred Shares, if any, voting as a single class. See “Investment Restrictions” in the SAI.

Investment Philosophy and Process

The Adviser allocates the Fund’s assets between the Tactical Municipal Closed-End Fund Strategy and the Municipal Bond Income Strategy (as described above). The amount allocated to each of the principal strategies may change depending on the Adviser’s assessment of market risk, security valuations, market volatility, and the prospects for earning income and capital appreciation. See “Risks-Structural Risks-Multi-Manager Risk.”

Tactical Municipal Closed-End Fund Strategy. The Adviser considers a number of factors when selecting Underlying Funds, including fundamental and technical analysis to assess the relative risk and reward potential throughout the financial markets. The term “tactical” is used to indicate that the portion of the Fund’s Managed Assets allocated to this strategy that invests in CEFs to take advantage of pricing discrepancies in the CEF market.

In selecting CEFs, the Adviser opportunistically utilizes a combination of short-term and longer-term trading strategies to seek to derive value from the discount and premium spreads associated with CEFs by identifying pricing aberrations. The Adviser employs both a quantitative and qualitative approach in its selection of CEFs and has developed proprietary screening models and algorithms to trade CEFs. The Adviser’s mean reversion investing looks to capitalize on changes within the pricing of a CEF and, based upon its research and analysis, a view that it will revert to historical pricing. The Adviser employs the following trading strategies, among others:

Statistical Analysis (Mean Reversion)

●

Using proprietary quantitative models, the Adviser seeks to identify CEFs that are trading at compelling absolute and/or relative discounts.

●

The Adviser attempts to capitalize on the perceived mispricing if the Adviser believes that the discount widening is irrational and expects the discount to narrow to longer-term mean valuations.

Corporate Actions
	●	The Adviser pursues investments in CEFs that have announced, or the Adviser believes are likely to announce, certain corporate actions that may drive value for their shareholders.
	●	The Adviser has developed trading strategies that focus on CEF tender offers, rights offerings, shareholder distributions, open-endings and liquidations.

Shareholder Activism

	●	The Adviser assesses activism opportunities by determining a CEF’s susceptibility to dissident activity and analyzing the composition of the fund’s shareholder register. The Fund, in seeking to achieve its investment objectives, will not take activist positions in the Underlying Funds.

In employing its trading strategies, the Adviser conducts an extensive amount of due diligence on various fund sponsors, investment managers and funds, including actively monitoring regulatory filings, analyzing a fund’s registration statements, financial statements and organizational documents, as well as conducting proprietary research, such as speaking with fund sponsors, underwriters, sell-side brokers and investors.

See “Investment Philosophy and Process-Tactical Municipal Closed-End Fund Strategy.”

Municipal Bond Income Strategy. The Subadviser believes inefficiencies exist in the tax-exempt and tax-advantaged securities markets. In order to capitalize on these opportunities, the Subadviser applies both a top-down and bottom-up research investment process. The Subadviser’s top-down analysis considers the economic, interest rate, inflation outlook and other economic variables to guide overall portfolio structure. The Subadviser employs a value-oriented security selection process to invest in securities it believes to be mispriced which offer a yield advantage. In choosing investments, the Subadviser analyzes the credit quality of issuers and considers the yields available on municipal bonds with different maturities. In addition, the Subadviser reviews macroeconomic events, technical characteristics in the municipal bond market, tax policies, as well as analyzing individual municipal securities and sectors. The Subadviser seeks to reduce volatility through its disciplined investment process and investment risk management.

The Subadviser may sell a security if it no longer believes the security will contribute to meeting the investment objectives of the Fund. In considering whether to sell a security, the Subadviser may evaluate, among other things, the condition of the economy and meaningful changes in the issuer’s financial condition.

See “Investment Philosophy and Process-Municipal Bond Income Strategy.”

Limited Term Fund Structure and Eligible Tender Offer	The Fund will terminate on or before July 25, 2031 (the “Termination Date”); provided, that if the Board of Directors believes that, under then-current market conditions, it is in the best interests of the Fund to do so, the Fund may extend the Termination Date: (i) once for up to one year (i.e., up to July 25, 2032), and (ii) once for up to an additional six months (i.e., up to January 25, 2033), in each case upon the affirmative vote of a majority of the Board of Directors and without the approval of Common Shareholders. In determining whether to extend the Termination Date, the Board of Directors may consider the inability to sell the Fund’s assets in a time frame consistent with the termination due to lack of market liquidity or other extenuating circumstances. Additionally, the Board of Directors may determine that market conditions are such that it is reasonable to believe that, with an extension, the Fund’s remaining assets will appreciate and generate income in an amount that, in the aggregate, is meaningful relative to the cost and expense of continuing the operation of the Fund.

	In anticipation of the Termination Date (such period of time, the “wind-down period”), the Fund may begin liquidating all or a portion of the Fund’s portfolio, and may deviate from its investment policies and may not achieve its investment objective. During the wind-down period (or in anticipation of an Eligible Tender Offer), the Fund’s portfolio composition may change as more of its portfolio holdings are called or sold and portfolio holdings are disposed of in anticipation of liquidation. Rather than reinvesting the proceeds of matured, called or sold securities in accordance with the investment program described above, the Fund may invest such proceeds in short term or other lower yielding securities or hold the proceeds in cash, which may adversely affect its performance. In addition, within twelve months preceding the Termination Date, the Board of Directors may cause the Fund to conduct an Eligible Tender Offer. An Eligible Tender Offer would consist of a tender offer to all Common Shareholders to purchase Common Shares of the Fund at a price equal to the NAV per Common Share on the expiration date of the tender offer. The Board of Directors has established that, following an Eligible Tender Offer, the Fund must have at least $100 million of net assets to ensure the continued viability of the Fund (the “Termination Threshold”).
	In an Eligible Tender Offer, the Fund will offer to purchase all Common Shares held by each Common Shareholder; provided, that if the number of properly tendered Common Shares would result in the Fund’s net assets totaling less than the Termination Threshold, the Eligible Tender Offer will be terminated and no Common Shares will be repurchased pursuant to the Eligible Tender Offer. Instead, the Fund will begin (or continue) liquidating its portfolio and proceed to terminate on or before the Termination Date. The Adviser will pay all costs and expenses associated with the making of an Eligible Tender Offer, other than brokerage and related transaction costs associated with the disposition of portfolio investments in connection with the Eligible Tender Offer, which will be borne by the Fund and its Shareholders. An Eligible Tender Offer would be made, and Shareholders would be notified thereof, in accordance with the requirements of the 1940 Act, the Securities Exchange Act of 1934 (the “Exchange Act”) and the applicable tender offer rules thereunder (including Rule 13e-4 and Regulation 14E under the Exchange Act).

	If the number of properly tendered Common Shares would result in the Fund’s net assets equaling or totaling greater than the Termination Threshold, all Common Shares properly tendered and not withdrawn will be purchased by the Fund pursuant to the terms of the Eligible Tender Offer. The Fund’s purchase of tendered Common Shares pursuant to a tender offer will have tax consequences for tendering Common Shareholders and may have tax consequences for non-tendering Common Shareholders. In addition, the Fund would continue to be subject to its obligations with respect to its issued and outstanding preferred stock or debt securities, if any.

	All Common Shareholders remaining after a tender offer will be subject to proportionately higher expenses due to the reduction in the Fund’s total assets resulting from payment for the tendered Common Shares. A reduction in net assets, and the corresponding increase in the Fund’s expense ratio, could result in lower returns and put the Fund at a disadvantage relative to its peers and potentially cause the Fund to trade at a wider discount to NAV than it otherwise would. Such reduction in the Fund’s total assets may also result in less investment flexibility, reduced diversification and greater volatility for the Fund, and may have an adverse effect on the Fund’s investment performance. Moreover, the resulting reduction in the number of outstanding Common Shares could cause the Common Shares to become thinly traded or otherwise adversely impact the secondary market trading of such shares. See “Risks-Structural Risks-Limited Term and Eligible Tender Offer Risk.”

Following the completion of an Eligible Tender Offer, the Board of Directors may eliminate the limited term structure of the Fund upon the affirmative vote of a majority of the Board of Directors and without the approval of Common Shareholders. In making such decision, the Board of Directors will take such actions with respect to the continued operations of the Fund as it deems to be in the best interests of the Fund, based on market conditions at such time, the extent of Common Shareholder participation in the Eligible Tender Offer and all other factors deemed relevant by the Board of Directors in consultation with the Adviser and Subadviser, taking into account that the Adviser and Subadviser may have a potential conflict of interest in seeking to convert to a perpetual fund (or in seeking to extend the Termination Date). The Fund is not required to conduct additional tender offers following an Eligible Tender Offer and conversion to a perpetual structure. Therefore, remaining Common Shareholders may not have another opportunity to participate in a tender offer or exchange their Common Shares for the then-existing NAV per Common Share.

The Fund is not a so called “target date” or “life cycle” fund whose asset allocation becomes more conservative over time as its target date, often associated with retirement, approaches. In addition, the Fund is not a “target term” fund whose investment objective is to return its original NAV on the termination date. See “Certain Provisions of the Fund’s Charter and Bylaws and Of Maryland Law” and “Risks-Structural Risks-Limited Term and Eligible Tender Offer Risk.”

Use of Leverage

The Fund may borrow money and/or issue Preferred Shares, notes or debt securities for investment purposes. These practices are known as leveraging. In addition, the Fund may enter into derivative and other transactions that have the effect of leverage. Such other transactions may include tender option bond transactions (as described herein). The Adviser determines whether or not to engage in leverage based on its assessment of conditions in the debt and credit markets. As of the time immediately after it enters into any of the foregoing transactions, the Fund will seek to limit its overall effective leverage to 45% of its Managed Assets. On December 24, 2020, the Fund entered into a credit agreement for margin financing with Pershing LLC (the “Pershing Facility”). The Pershing Facility permits the Fund to borrow funds that are collateralized by assets held in a special custody account held at State Street Bank & Trust Co. pursuant to a Special Custody and Pledge Agreement. Through March 28, 2022, borrowings under the Pershing Facility bear interest at the overnight bank funding rate plus 90 basis points for a term of 60 calendar days. Borrowings under this arrangement bear interest at the overnight bank funding rate plus 80 basis points. The Fund did not utilize the Pershing Facility during the fiscal year ended June 30, 2024.

On March 9, 2023, the Fund entered into an additional credit agreement with BNP Paribas (“BNP Credit Agreement”). The BNP Credit Agreement permits the Fund to borrow funds that are collateralized by assets held at BNP Paribas pursuant to the BNP Credit Agreement. Under the terms of the BNP Credit Agreement, the Fund may borrow up to $15,000,000 bearing an interest rate of the Overnight Bank Funding Rate plus a fixed rate determined by the securities pledged as collateral. Any unused portion of the BNP Credit Agreement is subject to a commitment fee of 0.50% of the unused portion of the facility until a utilization of 80% or greater is met. The Fund did not utilize the BNP Credit Agreement during the fiscal year ended June 30, 2024. As of December 31, 2024, there was $4.1 million outstanding on the BNP Credit Agreement.

The Fund currently anticipates that leverage will be obtained through borrowings from banks or other financial institutions and the use of proceeds received from tender option bond transactions. See “-Tender Option Bonds.” To date, the Fund has not issued any Preferred Shares or debt securities.

The provisions of the 1940 Act provide that the Fund may borrow or issue notes or debt securities in an amount up to 33 1/3% of its total assets or may issue Preferred Shares in an amount up to 50% of the Fund’s total assets (including the proceeds from leverage). With respect to the Fund’s anticipated investments in TOB Residuals issued by a tender option bond trust (as further discussed below under “-Tender Option Bonds”), the Fund will treat such investments as derivatives in compliance with Rule 18f-4 under the 1940 Act. See “Risks-Investment-Related Risks-Legislation and Regulatory Risks.”

The use of leverage by the Fund can magnify the effect of any losses. If the income and gains earned on the securities and investments purchased with leverage proceeds are greater than the cost of the leverage, returns will be greater than if leverage had not been used. Conversely, if the income and gains from the securities and investments purchased with such proceeds do not cover the cost of leverage, returns will be less than if leverage had not been used. The use of leverage magnifies gains and losses to Common Shareholders. Since the holders of common stock pay all expenses related to the issuance of debt or use of leverage, any use of leverage would create a greater risk of loss for the Common Shares than if leverage is not used. There can be no assurance that a leveraging strategy will be successful during any period in which it is employed. See “Use of Leverage” and “Risks-Structural Risks-Leverage Risks.”

Tender Option Bonds. The Fund may leverage its assets through the use of proceeds received from tender option bond transactions. In a tender option bond transaction, a tender option bond trust (a “TOB Issuer”) is typically established by forming a special purpose trust into which the Fund, or an agent on behalf of the Fund, transfers municipal bonds or other municipal securities. A TOB Issuer typically issues two classes of beneficial interests: short-term floating rate notes (“TOB Floaters”), which are sold to third party investors, and residual interest municipal tender option bonds (“TOB Residuals”), which are generally issued to the Fund. The Fund may invest in both TOB Floaters and TOB Residuals, including TOB Floaters and TOB Residuals issued by the same TOB Issuer. The Fund may not invest more than 5% of its Managed Assets in any single TOB Issuer. The Fund does not currently intend to invest in TOB Residuals issued by a TOB Issuer that was not formed for the Fund, although it reserves the right to do so in the future.

Under accounting rules, securities of the Fund that are deposited into a TOB Issuer are treated as investments of the Fund, and are presented on the Fund’s Schedule of Investments and outstanding TOB Floaters issued by a TOB Issuer are presented as liabilities in the Fund’s Statement of Assets and Liabilities. Interest income from the underlying security is recorded by the Fund on an accrual basis. Interest expense incurred on the TOB Floaters and other expenses related to remarketing, administration and trustee services to a TOB Issuer are reported as expenses of the Fund.

For TOB Floaters, generally, the interest rate earned will be based upon the market rates for municipal securities with maturities or remarketing provisions that are comparable in duration to the periodic interval of the tender option, which may vary from weekly, to monthly, to extended periods of one year or multiple years. Since the option feature has a shorter term than the final maturity or first call date of the underlying securities deposited in the TOB Issuer, the Fund, if it is the holder of the TOB Floaters, relies upon the terms of the agreement with the financial institution furnishing the option as well as the credit strength of that institution. As further assurance of liquidity, the terms of the TOB Issuer provide for a liquidation of the municipal security deposited in the TOB Issuer and the application of the proceeds to pay off the TOB Floaters.

There are inherent risks with respect to investing in a TOB Issuer. These risks include, among others, the bankruptcy or default of the issuer of the securities deposited in the TOB Issuer, a substantial downgrade in the credit quality of the issuer of the securities deposited in the TOB Issuer, the inability of the TOB Issuer to obtain liquidity support for the TOB Floaters, a substantial decline in the market value of the securities deposited in the TOB Issuer, or the inability of the sponsor to remarket any TOB Floaters tendered to it by holders of the TOB Floaters. See “Risks-Investment-Related Risks-Tender Option Bonds Risk.” The aggregate principal amount of borrowings from the use of proceeds from tender option bond transactions represented approximately 38.87% of Managed Assets as of December 31, 2024. Asset coverage from tender option bond transactions was 257%.

Dividends and Distributions

The Fund has implemented a level distribution policy (the “Level Distribution Policy”). Under the Level Distribution Policy, the Fund intends to make monthly distributions to common shareholders at a constant and fixed (but not guaranteed) rate (which is annually reset) equal to 6.75% of the average of the Fund’s NAV per share as reported for the final five trading days of the preceding calendar year. The rate disclosed is as of the date of this Prospectus.

Under the Level Distribution Policy, to the extent that sufficient investment income is not available on a monthly basis, the Fund’s distributions could consist of return of capital in order to maintain the distribution rate. The amount treated as a return of capital will reduce a shareholder’s adjusted basis in the shareholder’s shares, thereby increasing the potential gain or reducing the potential loss on the sale of shares. Investors should not make any conclusions about the Fund’s investment performance from the amount of the Fund’s distributions or from the terms of the Fund’s Level Distribution Policy. Dividends and distributions may be payable in cash or common shares, with shareholders having the option to receive additional common shares in lieu of cash. The Fund may at times, in its discretion, pay out less than the entire amount of net investment income earned in any particular period and may at times pay out such accumulated undistributed income in addition to net investment income earned in other periods in order to permit the Fund to maintain a more stable level of distributions. As a result, the dividend paid by the Fund to common shareholders for any particular period may be more or less than the amount of net investment income earned by the Fund during such period. The Fund’s ability to maintain a stable level of distributions to shareholders will depend on a number of factors, including the stability of income received from its investments. The amount of monthly distributions could vary depending on a number of factors, including the costs of any leverage. As portfolio and market conditions change, the amount of dividends on the Fund’s common shares could change. For federal income tax purposes, the Fund is required to distribute substantially all of its net investment income each year to both reduce its federal income tax liability and to avoid a potential federal excise tax. The Fund intends to distribute all realized net capital gains, if any, at least annually. See “Dividends and Distributions.”

Dividend Reinvestment Plan	The Fund has an automatic dividend reinvestment plan (the “Plan”) commonly referred to as an “opt-out” plan. Each Common Shareholder who participates in the Plan will have all distributions of dividends and capital gains automatically reinvested in additional Common Shares. The automatic reinvestment of dividends and distributions in Common Shares will not relieve participants of any federal, state or local income tax that may be payable (or required to be withheld) on such dividends and distributions, even though such participants have not received any cash with which to pay the resulting tax.

	Common Shareholders who elect not to participate in the Plan will receive all distributions in cash. All correspondence or questions concerning the Plan, including how a Common Shareholder may opt out of the Plan, should be directed to DST Systems, Inc., (844) 569-4750 (the “Plan Administrator”). Beneficial owners of Common Shares who hold their Common Shares in the name of a broker or nominee should contact the broker or nominee to determine whether and how they may participate in, or opt out of, the Plan. See “Dividend Reinvestment Plan” and “U.S. Federal Income Tax Matters.”
Listing of Common Shares	The Fund’s currently outstanding common shares are, and the Common Shares offered in this Prospectus and any applicable prospectus supplement will be, subject to notice of issuance, listed on the New York Stock Exchange (“NYSE”) under the trading or “ticker” symbol “RMM.” The NAV of the Fund's common shares at the close of business on March 11, 2025 was $15.93 per share, and the last sale price of the Fund's common stock on the NYSE on such date was $14.57.
Risk Considerations	*Risk is inherent in all investing.* Investing in any investment company security involves risks, including the risk that you may receive little or no return on your investment or even that you may lose part or all of your investment. Therefore, before investing in the Fund, you should consider the risks more fully set forth under “Risks” beginning on page 29 (as well as the other information in this Prospectus, the applicable prospectus supplement and the SAI), which provides a discussion of the principal risk factors associated with an investment in the Fund specifically, as well as those factors generally associated with an investment in a company with investment objectives, investment policies, capital structure or trading markets similar to the Fund. Given the nature of the Fund’s investment strategies, these principal risks include risks associated with investments in municipal bonds, other investment companies and below investment grade-rated securities; risks associated with the use of leverage, including the use of tender option bond transactions, derivatives and short sales; and risks related to interest rates, management of the Fund’s duration and tax matters.

Administrator, Fund
Accountant, Transfer
Agent, Dividend Disbursing
Agent and Custodian

ALPS Fund Services, Inc. (“AFS”) is the Fund’s administrator. Under an Administration, Bookkeeping and Pricing Services Agreement (the “Administration Agreement”), AFS is responsible for calculating NAVs, providing additional fund accounting and tax services, and providing fund administration and compliance-related services. State Street Bank & Trust Co. serves as the Fund’s custodian. DST Systems, Inc. serves as the Fund’s transfer agent, registrar, Plan Administrator and dividend disbursing agent. See “Administrator, Fund Accountant, Transfer Agent, Dividend Disbursing Agent and Custodian.”

SUMMARY OF FUND EXPENSES

The following table shows estimated Fund expenses as a percentage of net assets attributable to Common Shares. The expenses shown in the table and related footnotes, along with the example, are based on the Fund’s capital structure as of December 31, 2024. Actual expenses may be greater or less than those shown below.

Shareholder Transaction Expenses	As a Percentage of Offering Price
Sales Load	–%*
Offering Expenses Borne by Common Shareholders of the Fund	–%*
Dividend Reinvestment Plan Fees⁽¹⁾	–*
Preferred Shares Offering Expenses Borne by the Fund (as a percentage of net assets attributable to Common Shares)	–%*

^*	The applicable prospectus supplement to be used in connection with any sales of Common Shares or Preferred Shares will set forth any applicable sales load and the estimated offering expenses borne by the Fund under an Offering.
⁽¹⁾	There will be no brokerage charges with respect to Common Shares issued directly by the Fund under the dividend reinvestment plan. You will pay brokerage charges in connection with open market purchases or if you direct the plan agent to sell your Common Shares held in a dividend reinvestment account.

Annual Expenses	As a Percentage of Net Assets Attributable to Common Shares (Assuming the Use of Leverage Equal to 39.64% of the Fund’s Managed Assets)
Management fee⁽²⁾	2.28%
Leverage costs^(3)(4)(5)	2.43%
Dividends on Preferred Shares⁽⁶⁾	–%
Other expenses	0.04%
Acquired fund fees and expenses ⁽⁷⁾	2.08%
Total annual expenses	6.83%

The management fee paid by the Fund to the Adviser is essentially an all-in fee structure (the “unified management fee”), including the fee paid to the Adviser for advisory, supervisory, administrative, shareholder servicing and other services. However, the Fund (and not the Adviser) will be responsible for certain additional fees and expenses, which are reflected in the table above, that are not covered by the unified management fee. The unified management fee also includes fees payable by the Adviser to the Subadviser for advisory services. The unified management fee is charged as a percentage of the Fund’s average daily Managed Assets, as opposed to net assets. The Fund’s Managed Assets for the period represents the average daily net assets for the six-month period ended December 31, 2024 plus the leverage outstanding during the period as described in footnote (5). With leverage, Managed Assets are greater in amount than net assets, because Managed Assets include assets attributable to the Fund’s use of leverage created by its borrowings and tender option bond transactions. In addition, the mark-to-market value of the Fund’s derivatives will be used for purposes of calculating Managed Assets. The management fee of 1.40% of the Fund’s Managed Assets represents 2.28% of net assets attributable to Common Shares assuming the use of leverage in an amount of 39.64% of the Fund’s Managed Assets.

	⁽⁴⁾
	⁽⁵⁾
	⁽⁶⁾
	⁽⁷⁾

The purpose of the table above and the example below is to help you understand the fees and expenses that you, as a Common Shareholder, would bear directly or indirectly. The expenses shown in the table under “Other Expenses” and “Total Annual Expenses” assume that the Fund has not issued any additional Common Shares.

Example ⁽⁸⁾

The example illustrates the expenses you would pay on a $1,000 investment in Common Shares, assuming (1) “Total annual expenses” of 6.83% of net assets attributable to Common Shares, and (2) a 5% annual return.

	1 year	3 years	5 years	10 years
Total Expenses Incurred	$68	$199	$326	$624

The example should not be considered a representation of future expenses. Actual expenses may be greater or less than those assumed.

The applicable prospectus supplement to be used in connection with any sales of Common Shares or Preferred Shares will set forth any applicable sales load and the estimated offering expenses borne by the Fund under an Offering.

(1)

There will be no brokerage charges with respect to Common Shares issued directly by the Fund under the dividend reinvestment plan. You will pay brokerage charges in connection with open market purchases or if you direct the plan agent to sell your Common Shares held in a dividend reinvestment account.

(2)

(3)

The actual amount of interest expense borne by the Fund will vary over time in accordance with the level of the Fund’s use of leverage and variations in market interest rates. See “Use of Leverage.”

(4)

The “Leverage Costs” include the expenses associated with the Fund’s tender option bond (“TOB”) transactions, including remarketing, administration and trustee services to a TOB issuer.

(5)

Interest and fees on leverage in the table reflect the cost to the Fund of borrowings and TOB transactions, expressed as a percentage of the Fund’s net assets as of December 31, 2024, based on interest rates in effect as of December 31, 2024. The table assumes the use of leverage from borrowings and the proceeds of TOB transactions representing, in the aggregate, 39.64% of Managed Assets at a weighted average annual expense to the Fund of 3.89%.

(6)

As of the date of this Prospectus, the Fund has not issued any Preferred Shares. The applicable prospectus supplement will set forth the expense related to any Preferred Shares issued in the future.

(7)

The “Acquired fund fees and expenses” disclosed above are based on the expense ratios for the most recent fiscal year of the Underlying Funds in which the Fund has invested, which may change substantially over time and, therefore, significantly affect “Acquired fund fees and expenses.” These amounts are based on the total expense ratio disclosed in each Underlying Fund’s most recent shareholder report. “Acquired fund fees and expenses” are not charged directly to the Fund, but rather reflect the estimated pro rata portion of the Underlying Funds’ fees attributable to the Fund’s investments in shares of the Underlying Funds. The 2.08% shown as “Acquired fund fees and expenses” reflects estimated operating expenses of the Underlying Funds and transaction-related fees. Certain Underlying Funds in which the Fund intends to invest generally charge a management fee of 1.00% to 2.00%, which are included in “Acquired fund fees and expenses,” as applicable. Acquired fund fees and expenses are borne indirectly by the Fund, but they are not reflected in the Fund’s financial statements; and the information presented in the table will differ from that presented in the Fund’s financial highlights.

(8)

The example does not include sales load or estimated offering costs. The example should not be considered a representation of future expenses. The example assumes that the estimated “Other expenses” set forth in the table are accurate and that all dividends and distributions are reinvested at net asset value (“NAV”) and that the Fund is engaged in leverage of 39.64% of Managed Assets, assuming interest and fees on leverage of 2.43%. The interest and fees on leverage is expressed as an interest rate and represents interest and fees payable on borrowings, as well as interest and fees payable for the Fund’s TOB transactions. Actual expenses may be greater or less than those shown. Moreover, the Fund’s actual rate of return may be greater or less than the hypothetical 5% annual return shown in the example.

The purpose of the table and the example above is to help investors understand the fees and expenses that they, as Common Shareholders, would bear directly or indirectly.

FINANCIAL HIGHLIGHTS

The Fund’s “Financial Highlights” and the report of the Fund's independent registered public accounting firm, Cohen & Company, Ltd. ("Cohen"), thereon, contained in the following document filed by the Fund with the SEC, is hereby incorporated by reference into this Prospectus: the annual report for the year ended June 30, 2024 contained in the Fund’s Form N-CSR filed with the SEC on September 6, 2024. The Fund’s “Financial Highlights” contained in the following document filed by the Fund with the SEC, is also hereby incorporated by reference into this Prospectus: the semi-annual report for the six-months ended December 31, 2024 contained in the Fund's Form N-CSR filed with the SEC on March 7, 2025.

SENIOR SECURITIES

The following table sets forth certain information regarding the Fund's senior securities as of the end of the Fund's prior fiscal years since the Fund's inception and for the six months ended December 31, 2024. Audited information regarding the Fund's senior securities is incorporated by reference from the Fund's Form N-CSR. The Fund's senior securities during this time period are comprised of outstanding indebtedness, which constitutes a "senior security" as defined in the 1940 Act.

Senior Securities Representing Indebtedness

Period/Fiscal Year Ended	Principal Amount Outstanding¹		Asset Coverage Per $1,000²
December 31, 2024 (unaudited)	$	4,100,000	$	78,758
June 30, 2024	$	–	$	–
June 30, 2023	$	–	$	–
June 30, 2022	$	10,000,000	$	33,406
June 30, 2021	$	10,000,000	$	41,681
June 30, 2020³	$	–	$	–

(1)

Principal amount outstanding represents the principal amount owed by the Fund to lenders under credit facility arrangements in place at the time.

(2)

The asset coverage ratio is calculated by subtracting the Fund’s total liabilities and indebtedness not represented by senior securities from the Fund’s total assets, dividing the result by the aggregate amount of the Fund’s senior securities representing indebtedness then outstanding, and then multiplying by $1,000.

(3)

For the period July 25, 2019, commencement of operations, to June 30, 2020.

MARKET AND NET ASSET VALUE INFORMATION

The Fund’s Common Shares are listed on the NYSE under the symbol “RMM.” The Fund’s Common Shares commenced trading on the NYSE on July 25, 2021.

The Fund’s Common Shares have traded both at a premium and at a discount in relation to NAV. Shares of closed-end investment companies frequently trade at a discount from NAV. The Fund’s issuance of the Common Shares may have an adverse effect on prices in the secondary market for the Fund’s Common Shares by increasing the number of Common Shares available, which may put downward pressure on the market price for the Fund’s Common Shares.

The Fund may (but is not obligated to) take action to repurchase shares in the open market or make tender offers for its shares at or near NAV. During the pendency of any tender offer, the Fund will publish how Common Shareholders may readily ascertain the NAV. Repurchase of the Common Shares may have the effect of reducing any market discount to NAV. There is no assurance that, if action is undertaken to repurchase or tender for shares, such action will result in the shares trading at a price which approximates their NAV.

The following table sets forth for each of the periods indicated the high and low closing market prices for Common Shares of the Fund on the NYSE, the NAV per share and the premium or discount to NAV per share at which the Fund’s Common Shares were trading. NAV is determined daily as of the close of regular trading on the NYSE (normally 4:00 p.m. Eastern Time).

	MARKET PRICE⁽¹⁾		NET ASSET VALUE ⁽²⁾		PREMIUM/(DISCOUNT) TO NET ASSET VALUE⁽³⁾
Quarter Ended	High	Low	High	Low	High	Low
September 30, 2019	$20.70	$19.95	$20.38	$20.00	1.57%	-0.25%
December 31, 2019	$20.30	$19.34	$20.05	$20.38	1.25%	-5.10%
March 31, 2020	$21.21	$13.45	$20.76	$14.33	2.17%	-6.14%
June 30, 2020	$18.59	$16.15	$17.74	$16.76	4.77%	-3.64%
September 30, 2020	$17.70	$16.60	$18.48	$18.42	-4.22%	-9.88%
December 31, 2020	$18.01	$16.53	$19.45	$18.38	-7.40%	-10.07%
March 31, 2021	$19.15	$17.75	$20.03	$19.62	-4.39%	-9.53%
June 30, 2021	$20.40	$18.78	$20.65	$20.19	-1.21%	-6.98%
September 30, 2021	$21.57	$19.70	$20.35	$20.13	6.00%	-2.14%
December 31, 2021	$20.15	$19.24	$20.26	$19.93	-0.54%	-3.46%
March 31, 2022	$20.17	$16.77	$20.40	$18.02	-1.13%	-6.94%
June 30, 2022	$17.24	$14.80	$18.28	$16.12	-5.69%	-8.19%
September 30, 2022	$17.04	$14.30	$17.26	$15.77	-1.27%	-9.32%
December 31, 2022	$15.74	$13.50	$16.42	$14.91	-4.14%	-9.46%
March 31, 2023	$16.40	$14.81	$16.94	$16.18	-3.19%	-8.47%
June 30, 2023	$15.95	$14.67	$16.13	$16.06	-1.12%	-8.66%
September 30, 2023	$15.85	$13.70	$16.37	$14.73	-3.18%	-6.99%
December 31, 2023	$14.73	$12.42	$16.10	$14.37	-8.51%	-13.57%
March 31, 2024	$15.40	$14.10	$16.40	$16.13	-6.10%	-12.59%
June 30, 2024	$15.26	$14.52	$16.46	$16.14	-7.29%	-10.04%
September 30, 2024	$16.11	$15.13	$16.54	$16.35	-2.60%	-7.22%
December 31, 2024	$16.27	$14.42	$16.68	$16.15	-2.46%	-10.74%

(1)

Based on high and low closing market price for the respective quarter.

(2)

Based on the NAV calculated on the day of the high and low closing market prices, as applicable, as of the close of regular trading on the NYSE (normally 4:00 p.m. Eastern Time).

(3)

Calculated based on the information presented.

The last reported sale price, NAV per share and percentage discount to NAV per share of the Common Shares as of March 11, 2025 were $14.57, $15.93 and -8.54%, respectively. As of that same date, the Fund had 19,739,628 common shares outstanding and net assets of the Fund were $314,441,949.

In recognition of the possibility that Common Shares might trade at a discount to NAV, the Board of Directors may consider one or more actions that might be taken to seek to reduce or eliminate any material discount from NAV in respect of Common Shares, which may include the repurchase of such shares in the open market or in private transactions, the making of a tender offer for such shares or the conversion of the Fund to an open-end investment company. The Board of Directors may decide not to take any of these actions in the future. In addition, there can be no assurance any of these actions, or others, if undertaken, will reduce market discount.

THE FUND

RiverNorth Managed Duration Municipal Income Fund, Inc. (the “Fund”) is a diversified, closed-end management investment company registered under the Investment Company Act of 1940, as amended (the “1940 Act”). The Fund was organized as a Maryland corporation on March 20, 2019. The Fund will have an approximate twelve-year limited term unless otherwise determined by the Fund’s Board of Directors (the “Board of Directors”). On July 25, 2019, 19,739,247 shares of common stock were issued in connection with the Fund’s initial public offering. The Fund’s currently outstanding common stock is, and common stock offered in this Prospectus and any applicable prospectus supplement will be, listed on the New York Stock Exchange (“NYSE”) under the symbol “RMM.” The Fund’s principal office is located at 360 South Rosemary Avenue, Suite 1420, West Palm Beach, FL 33401, and its telephone number is (561) 484-7185. The shares of the Fund’s common stock offered by this Prospectus and any applicable prospectus supplement are hereinafter called “Common Shares” and the holders of Common Shares are called “Common Shareholders.” As used in this Prospectus, unless the context requires otherwise, “common shares” refers to the shares of the Fund’s common stock currently outstanding as well as those Common Shares offered by this Prospectus and the holders of common shares are called “common shareholders.”

The following table provides information about the Fund’s outstanding securities as of December 31, 2024:

Title of Class	Amount Authorized	Amount Held by the Fund or for its Account	Amount Outstanding
Common Shares	50,000,000	0	19,739,628

THE OFFERING

The Fund may offer, from time to time, up to $400,000,000 aggregate initial offering price of (i) Common Shares, (ii) shares of its preferred stock (“Preferred Shares”), and/or (iii) subscription rights to purchase Common Shares, Preferred Shares or both (“Rights” and, together with the Common Shares and the Preferred Shares, “Securities) in one or more offerings in amounts, at prices and on terms set forth in one or more supplements to this Prospectus. See “Description of the Fund’s Securities.”

The Fund may offer Securities directly to one or more purchasers, including existing common shareholders and/or preferred shareholders in a Rights offering, through agents that the Fund or the purchasers designate from time to time, or to or through underwriters or dealers. The prospectus supplement relating to the offering will identify any agents or underwriters involved in the sale of the Securities, and will set forth any applicable purchase price, fee, commission or discount arrangement between the Fund and such agents or underwriters or among underwriters or the basis upon which such amount may be calculated. The prospectus supplement relating to any sale of preferred stock will set forth the liquidation preference and information about the dividend period, dividend rate, any call protection or non-call period and other matters, including the terms, if any, on which the preferred stock may be exchanged for or converted into shares of common stock or any other security and, if applicable, the conversion or exchange price, or how it will be calculated, and the conversion or exchange period. A supplement to this Prospectus relating to any offering of subscription rights will set forth the number of shares (common or preferred) issuable upon the exercise of each right and the other terms of such Rights offering, including whether the Preferred Shares issuable upon the exercise of such right are convertible into Common Shares. The Fund may not sell Securities through agents, underwriters or dealers without delivery of this Prospectus and a prospectus supplement describing the method and terms of the offering of the Securities. See “Plan of Distribution.”

The Fund may offer Common Shares or Preferred Shares on an immediate, continuous or delayed basis. Offerings of Shares will be subject to the provisions of the 1940 Act, which generally require that the public offering price of common shares of a closed-end investment company (exclusive of distribution commissions and discounts) must equal or exceed the net asset value (“NAV”) per share of the company’s common stock (calculated within 48 hours of pricing), absent shareholder approval or under certain other circumstances. The Fund may, however, issue Common Shares pursuant to exercises of Rights at prices below NAV.

USE OF PROCEEDS

Unless otherwise specified in a prospectus supplement, the Fund expects to invest the net proceeds from any sales of Securities in accordance with the Fund’s investment objective and policies as stated below, or use such proceeds for other general corporate purposes within approximately three months of receipt of such proceeds. Pending any such use, the proceeds may be invested in cash, cash equivalents, short-term debt securities or U.S. government securities. A delay in the anticipated use of proceeds could lower returns and reduce the Fund’s distributions to common shareholders.

INVESTMENT OBJECTIVES, STRATEGIES AND POLICIES

The information in “Investment Objective, Strategies and Policies” is set forth in the Fund’s annual report on Form N-CSR for the year ended June 30, 2024 in the section entitled “Summary of Updated Information Regarding the Fund”, which is incorporated by reference into this Prospectus, and in any future filings we may file with the SEC that are incorporated by reference into this Prospectus. See “Incorporation by Reference” below for more information.

INVESTMENT PHILOSOPHY AND PROCESS

Statistical Analysis (Mean Reversion)

●	Using proprietary quantitative models, the Adviser seeks to identify CEFs that are trading at compelling absolute and/or relative discounts.

●	The Adviser will attempt to capitalize on the perceived mispricing if the Adviser believes that the discount widening is irrational and expects the discount to narrow to longer-term mean valuations.

Corporate Actions

●	The Adviser pursues investments in CEFs that have announced, or the Adviser believes are likely to announce, certain corporate actions that may drive value for their shareholders.

●	The Adviser has developed trading strategies that focus on CEF tender offers, rights offerings, shareholder distributions, open-endings and liquidations.

Shareholder Activism

●	The Adviser assesses activism opportunities by determining a CEF’s susceptibility to dissident activity and analyzing the composition of the fund’s shareholder register. The Fund, in seeking to achieve its investment objectives, will not take activist positions in the Underlying Funds.

USE OF LEVERAGE

The Fund may borrow money and/or issue preferred shares, notes or debt securities for investment purposes. These practices are known as leveraging. In addition, the Fund may enter into derivative and other transactions that have the effect of leverage. Such other transactions may include tender option bond transactions (as described herein). The Adviser determines whether or not to engage in leverage based on its assessment of conditions in the debt and credit markets. As of the time immediately after it enters into any of the foregoing transactions, the Fund will seek to limit its overall effective leverage to 45% of its Managed Assets.

On December 24, 2020, the Fund entered into a credit agreement for margin financing with Pershing LLC (the “Pershing Facility”). The Pershing Facility permits the Fund to borrow funds that are collateralized by assets held in a special custody account held at State Street Bank pursuant to a Special Custody and Pledge Agreement. Borrowings under this arrangement bear interest at the overnight bank funding rate plus 80 basis points.

On August 1, 2023, the Fund entered into an additional credit agreement with BNP Paribas (“BNP Facility”). The BNP Facility permits the Fund to borrow funds that are collateralized by assets held at BNP Paribas pursuant to the BNP Facility. Under the terms of the BNP Facility, the Fund may borrow up to $15,000,000 bearing an interest rate of the Overnight Bank Funding Rate plus a fixed rate determined by the securities pledged as collateral. Any unused portion of the BNP Facility is subject to a commitment fee of 0.50% of the unused portion of the facility until a utilization of 80% or greater is met.

The Fund did not utilize the Pershing or the BNP Facility for the year ended June 30, 2024. There was no outstanding balance on the Pershing or BNP Facility as of June 30, 2024. As of December 31, 2024, there was $4.1 million outstanding on the BNP Credit Agreement.

The Fund currently utilizes leverage obtained through borrowings from banks or other financial institutions and the use of proceeds received from tender option bond transactions. To date, the Fund has not issued any Preferred Shares or debt securities.

Under the 1940 Act, the Fund is not permitted to incur indebtedness unless immediately after doing so the Fund has an asset coverage of at least 300% of the aggregate outstanding principal balance of indebtedness (i.e., such indebtedness may not exceed 33 1/3% of the value of the Fund’s total assets including the amount borrowed). Additionally, under the 1940 Act, the Fund may not declare any dividend or other distribution upon any class of its shares, or purchase any such shares, unless the aggregate indebtedness of the Fund has, at the time of the declaration of any such dividend or distribution or at the time of any such purchase, asset coverage of at least 300% after deducting the amount of such dividend, distribution, or purchase price, as the case may be. Under the 1940 Act, the Fund is not permitted to issue Preferred Shares unless immediately after such issuance the total asset value of the Fund’s portfolio is at least 200% of the liquidation value of the outstanding Preferred Shares (i.e., such liquidation value may not exceed 50% of the Fund’s Managed Assets). In addition, the Fund is not permitted to declare any cash dividend or other distribution on its Common Shares unless, at the time of such declaration, the NAV of the Fund’s portfolio (determined after deducting the amount of such dividend or other distribution) is at least 200% of such liquidation value of the Preferred Shares. However, certain short-term borrowings (such as for cash management purposes) are not subject to the 33 1/3% limitation if (i) repaid within 60 days, (ii) not extended or renewed and (iii) not in excess of 5% of the total assets of the Fund. Normally, holders of Common Shares will elect the directors of the Fund except that the holders of any Preferred Shares will elect two directors. In the event the Fund failed to pay dividends on its Preferred Shares for two years, holders of Preferred Shares would be entitled to elect a majority of the directors until the dividends are paid.

The Fund may be subject to certain restrictions on investments imposed by lenders or by one or more rating agencies that may issue ratings for any senior securities issued by the Fund. Borrowing covenants or rating agency guidelines may impose asset coverage or Fund composition requirements that are more stringent than those imposed on the Fund by the 1940 Act. Since the holders of common stock pay all expenses related to the use of leverage, such use of leverage would create a greater risk of loss for the Fund’s Common Shares than if leverage is not used.

The Fund may enter into derivatives or other transactions (e.g., total return swaps) that may provide leverage (other than through borrowings or the issuance of preferred shares). The Fund may also invest in reverse repurchase agreements, total return swaps and derivatives or other transactions with leverage embedded in them in a limited manner or subject to a limit on leverage risk calculated based on value-at-risk, as required by Rule 18f-4 under the 1940 Act. These transactions will not cause the Fund to pay higher advisory or administration fee rates than it would pay in the absence of such transactions. However, these transactions entail additional expenses (e.g., transaction costs) which are borne by the Fund.

These transactions entail additional expenses (e.g., transaction costs) which are borne by the Fund. These types of transactions have the potential to increase returns to Common Shareholders, but they also involve additional risks. This additional leverage will increase the volatility of the Fund’s investment portfolio and could result in larger losses than if the transactions were not entered into.

Tender Option Bonds. The Fund leverages its assets through the use of proceeds received from tender option bond transactions. In a tender option bond transaction, a tender option bond trust (a “TOB Issuer”) is typically established by forming a special purpose trust into which the Fund, or an agent on behalf of the Fund, transfers municipal bonds or other municipal securities. A TOB Issuer typically issues two classes of beneficial interests: short-term floating rate notes (“TOB Floaters”), which are sold to third party investors, and residual interest municipal tender option bonds (“TOB Residuals”), which are generally issued to the Fund. The Fund may invest in both TOB Floaters and TOB Residuals, including TOB Floaters and TOB Residuals issued by the same TOB Issuer. The Fund may not invest more than 5% of its Managed Assets in any single TOB Issuer. The Fund does not currently intend to invest in TOB Residuals issued by a TOB Issuer that was not formed for the Fund, although it reserves the right to do so in the future.

The TOB Issuer receives Municipal Bonds or other municipal securities and then issues TOB Floaters to third party investors and a TOB Residual to the Fund. The Fund is paid the cash (less transaction expenses, which are borne by the Fund and therefore the holders of the Common Shares indirectly) received by the TOB Issuer from the sale of the TOB Floaters and typically will invest the cash in additional Municipal Bonds or other investments permitted by its investment policies. TOB Floaters may have first priority on the cash flow from the securities held by the TOB Issuer and are enhanced with a liquidity support arrangement from a third-party bank or other financial institution (the “liquidity provider”), which allows holders to tender their position at par (plus accrued interest). The Fund, in addition to receiving cash from the sale of the TOB Floaters, also receives the TOB Residual. The TOB Residual provides the Fund with the right to (1) cause the holders of the TOB Floaters to tender their notes to the TOB Issuer at par (plus accrued interest), and (2) acquire the underlying Municipal Bonds or other municipal securities from the TOB Issuer. In addition, all voting rights and decisions to be made with respect to any other rights relating to the underlying securities deposited in the TOB Issuer are passed through to the Fund, as the holder of the TOB Residual. Such a transaction, in effect, creates exposure for the Fund to the entire return of the securities deposited in the TOB Issuer, with a net cash investment by the Fund that is less than the value of the underlying securities deposited in the TOB Issuer. This multiplies the positive or negative impact of the underlying securities’ return within the Fund (thereby creating leverage).

The TOB Issuer may be terminated without the consent of the Fund upon the occurrence of certain events, such as the bankruptcy or default of the issuer of the underlying securities deposited in the TOB Issuer, a substantial downgrade in the credit quality of the issuer of the securities deposited in the TOB Issuer, the inability of the TOB Issuer to obtain liquidity support for the TOB Floaters, a substantial decline in the market value of the underlying securities deposited in the TOB Issuer, or the inability of the sponsor or remarketing agent to remarket any TOB Floaters tendered by holders of the TOB Floaters. In such an event, the TOB Floaters would be redeemed by the TOB Issuer at par (plus accrued interest) out of the proceeds from a sale of the underlying securities deposited in the TOB Issuer. If this happens, the Fund would be entitled to the assets of the TOB Issuer, if any, that remain after the TOB Floaters have been redeemed at par (plus accrued interest). If there are insufficient proceeds from the sale of these securities to redeem all of the TOB Floaters at par (plus accrued interest), the liquidity provider or holders of the TOB Floaters would bear the losses on those securities and there would be no recourse to the Fund’s assets (unless the Fund held a recourse TOB Residual). A recourse TOB Residual is generally a TOB Residual issued by a TOB Issuer in which the TOB Floaters represent greater than 75% of the market value of the securities at the time they are deposited in the TOB Issuer. If the Fund were to invest in a recourse TOB Residual to leverage its portfolio, it would typically be required to enter into an agreement pursuant to which the Fund is required to pay to the liquidity provider the difference between the purchase price of any TOB Floaters put to the liquidity provider by holders of the TOB Floaters and the proceeds realized from the remarketing of those TOB Floaters or the sale of the assets in the TOB Issuer. The Fund currently does not intend to use recourse TOB Residuals to leverage the Fund’s portfolio, but reserves the right to do so depending on future market conditions.

Effects of Leverage. The use of proceeds from tender option bond transactions represented approximately 38.87% of Managed Assets as of December 31, 2024. Asset coverage from tender option bond transactions was 257%. Borrowings under Pershing Facility bear interest at the overnight bank funding rate plus 80 basis points. Borrowings under the BNP Facility bear interest at the Overnight Bank Funding Rate plus a fixed rate determined by the securities pledged as collateral. Any unused portion of the BNP Facility is also subject to a commitment fee of 0.50% of the unused portion of the facility until a realization of 80% or greater is met. As of December 31, 2024, the average daily weighted interest rate applicable to the leverage attended through the use of tender option bond transactions during the period ended December 31, 2024 was 3.86% of the note obligation outstanding. The total weighted average cost of the leverage outstanding as of December 31, 2024 (inclusive of the Pershing Facility, BNP Facility and leverage attended through the use of tender option bond transactions) was 3.89% of the principal amount outstanding. Assuming that the Fund’s leverage costs remain as described above (at an assumed annual cost of 39.64% of the principal amount outstanding) the annual return that the Fund’s portfolio must experience (net of expenses) in order to cover its leverage costs would be 1.54%.

The following table is furnished in response to requirements of the SEC. It is designed to illustrate the effect of leverage on total return on Common Shares, assuming investment portfolio total returns (comprised of income, net expenses and changes in the value of investments held in the Fund’s portfolio) of -10%, -5%, 0%, 5% and 10%. These assumed investment portfolio returns are hypothetical figures and are not necessarily indicative of what the Fund’s investment portfolio returns will be. In other words, the Fund’s actual returns may be greater or less than those appearing in the table below. The table further reflects the use of leverage representing approximately 39.64% of the Fund’s Managed Assets and the Fund’s assumed annual leverage costs rate of 3.89% of the principal amounts outstanding.

Assumed Portfolio Return	-10.00%	-5.00%	0.00%	5.00%	10.00%
Common Share Total Return	-

Amendment: SEC Form N-2/A filed by RiverNorth Managed Duration Municipal Income Fund Inc.