UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

(Rule14a-101)

INFORMATION REQUIRED IN PROXY STATEMENT

SCHEDULE 14A INFORMATION

PROXY STATEMENT PURSUANT TO SECTION 14(a)

OF THE

SECURITIES EXCHANGE ACT OF 1934 (Amendment No.)

(Amendment No.    )

Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐

Check the appropriate box:

MANAGED DURATION INVESTMENT GRADE

MUNICIPAL FUND

(Name of Registrant as Specified in its Charter)

Not Applicable

(Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)

Payment of Filing Fee (Check the appropriate box):

MANAGED DURATION INVESTMENT GRADE MUNICIPAL FUND

200 Park Avenue,PARK AVENUE, 7^thTH FloorFLOOR

New York,NEW YORK, NY 10166

NOTICE OF ANNUALSPECIAL MEETING OF SHAREHOLDERS

DECEMBER 6, 2017JULY 12, 2018

New York, New York

September 29, 2017May 30, 2018

Important Notice Regarding the Availability of Proxy Materials for the AnnualSpecial Meeting of Shareholders to be held on December 6, 2017.July 12, 2018. The proxy statement and annual report to shareholders are available without charge at the respective websites listed below or by calling the Managed Duration Investment Grade Municipal Fund at1-877-848-4140.

Annual Report:https://www.insightinvestment.com/globalassets/documents/mzf-reports/mzf-annual-report-2017mzf-annual-report

Annual Proxy Statement:https://www.insightinvestment.com/globalassets/documents/mzf-reports/mzf-annual-proxy-statement-2017mzf-annual-proxy-statement

TO THE SHAREHOLDERS OF MANAGED DURATION INVESTMENT GRADE MUNICIPAL FUND:

The AnnualSpecial Meeting of Shareholders of the Managed Duration Investment Grade Municipal Fund (the “Fund”) will be held on December 6, 2017,July 12, 2018, at 10:30 a.m. Eastern Time, at the offices of Pepper Hamilton LLP, 899 Cassatt Road, Berwyn, Pennsylvania (the “Annual“Special Meeting”) forto consider and vote solely upon a proposal to liquidate and dissolve the following purposes:

The subjects referredFund pursuant to above are discussed in detaila Plan of Liquidation and Dissolution, as described more fully in the accompanying Proxy Statement accompanying this notice. Statement.

Each shareholder is invited to attend the AnnualSpecial Meeting in person. You will need proof of ownership of the Fund’s shares of beneficial interest to enter the meeting or, if your shares are held in a brokerage or bank account (in “street name”), a proxy from the street name holder. Shareholders of record at the close of business on September 18, 2017April 13, 2018 are entitled to notice of and to vote at the meeting or any postponement or adjournment thereof. If you cannot be present at the AnnualSpecial Meeting, we urge you to fill in, sign, and promptly return the enclosed proxy card in order that the AnnualSpecial Meeting can be held without additional expense and a maximum number of shares may be voted.

By Order of the Board of Trustees,

Clifford D. Corso, President

MANAGED DURATION INVESTMENT GRADE MUNICIPAL FUND

200 Park Avenue, 7^th Floor

New York, NY 10166

We encourage you to read the full text of the enclosed Proxy Statement to shareholders (“Proxy Statement”). For your convenience we also have provided questions and answers to frequently asked questions relating to, and a brief summary of, the proposals to be voted on by shareholders at the annualspecial meeting of shareholders to be held on December 6, 2017July 12, 2018 (the “Annual“Special Meeting”). The following “Frequently Asked Questions”“Questions and Answers” section is a summary and is not intended to be as detailed as the discussion found later in the Proxy Statement. For that reason, the information in this section is qualified in its entirety by reference to the enclosed Proxy Statement.

FREQUENTLY ASKED QUESTIONS AND ANSWERS

Q. What are shareholders being asked to vote upon?upon at the upcoming Special Meeting of Shareholders on July 12, 2018?

A. You are receiving these proxy materials, – a package that includeswhich include the Proxy Statement and your proxy card – because you have the right to vote on important matters concerning your investment inNotice of Special Meeting of Shareholders (“Notice”) of Managed Duration Investment Grade Municipal Fund (the “Fund”).

In summary, and Proxy Statement to provide you are being askedwith information you should review before voting on the proposal to elect two ofliquidate and dissolve the current Trustees to be Preferred Trustees and to reelect one current TrusteeFund (the “Liquidation”) pursuant to the Plan of Liquidation and Dissolution (the “Plan”), a form of which is attached to the Proxy Statement as Exhibit A, that will be presented at the Special Meeting on July 12, 2018.

On May 10, 2018, the Fund’s Board of Trustees (the “Board” or the “Trustees”) approved and declared advisable the Liquidation and directed that the Liquidation be submitted to the shareholders for approval at the Special Meeting. You are receiving this proxy material because you own shares of the Fund. Each shareholder of record of the Fund as of the close of business on April 13, 2018 (the “Record Date”) has the right under applicable legal requirements to vote on the Liquidation. The Liquidation will not occur unless approved by the lesser of (i) more than 50% of the votes entitled to be cast by the holders of the Fund’s common shares (“Common Shareholders”) and holders of the Fund’s preferred shares (“Preferred Shareholders”), voting together as a single class, or (ii) 67% or more of the Fund’s common shares and preferred shares present at the Special Meeting, voting as a single class, if the holders of more than 50% of the outstanding voting securities of the Fund are present or represented by proxy.

Q. Who is asking for my vote?

A. The Board is asking you to vote at the Special Meeting regarding the proposed Liquidation, as set forth in the Plan.

Q. Who is eligible to vote?

A. Shareholders of record at the close of business on the Record Date are entitled to vote at the Special Meeting or any adjournment or postponement of the Special Meeting. If you owned shares on the Record Date, you have the right to vote, even if you later sell or have sold the shares.

The holders of the Fund’s common stock and preferred stock vote together as a single class. Each share is entitled to one vote. Shares represented by properly executed proxies, unless revoked before or at the Special Meeting, will be voted according to shareholders’ instructions. If you sign and return a proxy card but do not fill in a vote, your shares will be voted “FOR” the Liquidation.

Q. How will the Liquidation work?

A. If the Fund’s shareholders approve the Liquidation, the Fund immediately thereafter will not engage in any business activities except to wind up its business, convert its portfolio securities to cash, and make one or more liquidating distributions to shareholders. More information on liquidating distributions is provided under “Summary of the Plan—Liquidating Distributions” in the Proxy Statement.

Q. Why is the Liquidation being proposed?

A. In recommending the Liquidation for approval by the shareholders, Fund management and the Board considered a variety of factors. These included (i) the Fund’s relatively small size and increasingly significant ownership of the Fund by a few large shareholders including “activist investors” (institutional shareholder who regularly acquire large positions inclosed-end funds and uses such ownership to influence a fund to take certain actions), (ii) the potential adverse consequences to the Fund of activities by such shareholders, and (iii) the recent trading discount. In addition, a large portion of the Fund’s shares are held by a shareholder that submitted several proposals for the 2018 Annual Meeting of Shareholders including a proposal to terminate the Fund’s investment advisory agreement with the Fund. This shareholder agreed to withdraw these proposals, based, in part, on the Fund’s intention to present shareholders with the opportunity to vote on the Liquidation pursuant to the Plan. The Board also considered the potential costs and other consequences to the Fund and its shareholders of contesting proposals submitted by activist investors, or implementing them if approved by shareholders. Fund management and the Board have also considered several alternative measures, such as converting the Fund into anopen-end investment company or engaging in a tender offer and determined that such proposals would not be in the best interest of the Fund or its shareholders as each would likely result in a much smaller Fund with decreasing economies of scale. Fund management and the Board determined that, on balance, the Liquidation would be in the best interests of the Fund and its shareholders.

If approved by the Fund’s shareholders, the Liquidation will allow shareholders of the Fund’s common stock to realize full net asset value for their common shares (and avoid the discount that such shareholders would currently realize if they sold their shares in the market), and permit Preferred Shareholders to receive the liquidation preference amount for their shares. In addition, the Board believes that an orderly liquidation of the Fund’s portfolio holdings will provide greater shareholder value than alternative measures to address the Fund’s size, proposals from large or activist investors, and trading discount issues, such as merging, converting the Fund to an open-ended fund or conducting a tender offer. In light of these factors, and after careful deliberation, the Board declared advisable, approved, and recommended that the Fund’s shareholders approve the Liquidation.

If the Fund’s shareholders do not approve the Liquidation, the Trustees will consider whether another course of action would benefit the Fund and its shareholders. Please review the Proxy Statement for a more detailed discussion about the reasons for the proposed Liquidation.

Q. When will the Liquidation and distributions to shareholders occur?

A. If the Fund’s shareholders approve the Liquidation, then, as described in greater detail in the Proxy Statement, the Fund’s assets will be liquidated and cash will be distributed to shareholders as soon as reasonably practicable after all of the Fund’s liabilities and expenses have been paid (or arranged to be paid) and a determination has been made as to which shareholders are entitled to receive payment of such liquidating distributions.

Q. Why am I being asked to elect two Preferred Trustees and reelect one current Trustee?

A. Atis the 2016 annual meeting of shareholders Ms. Harvey and Ms. Welsh were elected as Class I Trustees of the Fund, to serve until 2017. Mr. Spock was elected as a Class III Trustee of the Fund by holders of Common Shares and Preferred Shares, to serve until 2019.

Ms. Harvey is proposed for reelection by holders of Common Shares and Preferred Shares for a three year term ending in 2020. Ms. Welsh and Mr. Spock are each one of the two Trustees designated to represent the Preferred Shareholders. Ms. Welsh’s term as a Class I Trustee, if elected at this meeting, will expire in 2020, and Mr. Spock’s term as a Class III Trustee, if elected at this meeting, will expire at the end of his current term ending in 2019.

Q. What vote is required to elect each of the nominee Trustees?Board requesting my vote?

A. The electionFund’s Third Amended and Restated Agreement and Declaration of Ms. HarveyTrust (the “Declaration”) requires the Fund to obtain shareholder approval prior to the Board of Trustees will require the affirmative vote of a majorityliquidation and dissolution of the Common Shares and Preferred Shares (voting together as a single class) present and entitled toFund. Consequently, the Board is seeking your vote foron the election of Trustees at the Annual Meeting, in person or by proxy. The election of Mr. Spock and Ms. Welsh as Preferred Trustees will require the affirmative vote of a majority of the Preferred Shares (voting as a separate class) present and entitled to vote for the election of Trustees at the Annual Meeting, in person or by proxy.Liquidation.

Q. How does the Fund’s Board recommend that I vote?

A. After careful consideration, theThe Board unanimously recommends that you vote “FOR ALL”“FOR” the nomineesLiquidation.

Q. How can I vote my shares?

A. Please follow the instructions included on the enclosed proxy card.Proxy Card.

Q. How is a quorum established?

A. In accordance with the Fund’s Third Amended and Restated Agreement and Declaration, of Trust (the “Declaration of Trust”), a quorum is constituted by the presence in person or by proxy of the holders of record of a majority of the Common Shares and Preferred Shares entitled to vote at the AnnualSpecial Meeting, counted together as a single class. In the event that a quorum is not present at the AnnualSpecial Meeting or, in the event that a quorum is present but sufficient votes have not been received to approve any Board proposal, the AnnualSpecial Meeting may be adjourned to permit further solicitation of proxies. The presiding officer or Trusteetrustee of the Fund for the AnnualSpecial Meeting or the affirmative vote of a majority of the persons designated as proxies may adjourn the Annual

Special Meeting to permit further solicitation of proxies or for other reasons consistent with Delaware law and the Fund’s Declaration of Trust and the Fund’s Fourth Amended and RestatedBy-Laws. Unless otherwise instructed by a shareholder granting a proxy, the persons designated as proxies may use their discretionary authority to vote on questions of adjournment.

Q. Whom do I call if I have questions regarding the Proxy?

A. You can call Georgeson LLC at 1-888-206-0860.

Q. How do I place my vote?

A. In addition to the solicitation of proxies by mail, proxies also may be solicited by telephone, telegraph, personal interview or via the Internet. You may provide the Fund with your vote by mail with the enclosed proxy card, or by following the instructions on the enclosed proxy card, or in person at the AnnualSpecial Meeting. You may use the enclosed postage-paid envelope to mail your proxy card. Please follow the instructions on the enclosed proxy card to utilize any of these voting methods.

YOUR VOTE IS IMPORTANT. THANK YOU FOR PROMPTLY RECORDING YOUR VOTE.

MANAGED DURATION INVESTMENT GRADE MUNICIPAL FUND

200 Park Avenue, 7th Floor

New York, NY 10166

PROXY STATEMENT

ANNUALSPECIAL MEETING OF SHAREHOLDERS TO BE HELD ON DECEMBER 6, 2017JULY 12, 2018

This Proxy Statement is furnished in connection with the solicitation of proxies by the Board of Trustees (the “Board”) of Managed Duration Investment Grade Municipal Fund (the “Fund”) for use at the AnnualSpecial Meeting of Shareholders of the Fund to be held on December 6, 2017,July 12, 2018, at10:30 a.m. (Eastern Time), at the offices of Pepper Hamilton LLP, 899 Cassatt Road, Berwyn, Pennsylvania, and at any adjournments thereof (the “Annual“Special Meeting”). A Notice of AnnualSpecial Meeting of Shareholders and proxy card accompany this Proxy Statement and were first sent or delivered to shareholders on or about September 29, 2017.May 30, 2018.

VOTING

In addition to the solicitation of proxies by mail, proxies also may be solicited by telephone, telegraph, personal interview or via the Internet. The Fund has also requested brokers, dealers, banks or voting trustees, or their nominees, to forward proxy material to the beneficial owners of the Fund’s shares of beneficial interest. The enclosed proxy is revocable by you at any time prior to the exercise thereof by submitting a written notice of revocation or subsequently executed proxy to the Secretary of the Fund before or at the AnnualSpecial Meeting. Voting electronically or telephonically, or signing and mailing the proxy will not affect your right to give a later-dated proxy or to attend the AnnualSpecial Meeting and vote your shares in person. There is no shareholder statutory right of appraisal or dissent with respect to any matters to be voted on at the AnnualSpecial Meeting. The cost of soliciting proxies will be paid by the Fund.

THE PERSONS NAMED IN THE ACCOMPANYING PROXY WILL VOTE THE NUMBER OF SHARES REPRESENTED THEREBY AS DIRECTED OR, IN THE ABSENCE OF SUCH DIRECTION,FORALL OF THE INCUMBENT NOMINATED TRUSTEES AND THE TRANSACTION OF SUCH OTHER BUSINESS THAT MAY PROPERLY COME BEFORE THE MEETING AND ANY ADJOURNMENT THEREOF.

The Fund’s shares of beneficial interest trade on the New York Stock Exchange under the ticker symbol “MZF”.

The close of business on September 18, 2017,April 13, 2018, has been fixed as the record date for determination of shareholders entitled to receive notice of and to vote at the AnnualSpecial Meeting (the “Record Date”) and any adjournment or postponement thereof. Each shareholder is entitled to one vote for each full share and an appropriate fraction of a vote for each fractional share held, with no shares having cumulative voting rights. On September 18, 2017,April 13, 2018, there were 6,800,476 shares of the Fund’s common shares (“Common Shares”) outstanding and, there were 600 shares of the Fund’s Series 2020 Variable Rate MuniFund Term preferred sharesPreferred Shares (“Preferred Shares”) outstanding. These classes of stock are the only classes of stock currently authorized by the Fund.

In accordance with the Fund’s Third Amended and Restated Agreement and Declaration of Trust (the “Declaration of Trust”), a quorum is constituted by the presence in person or by proxy of the holders of record of a majority of the Common Shares and Preferred Shares entitled to vote at the Annual Meeting. However, a quorum for the election of Ms. Suzanne P. Welsh and Mr. Thomas E. Spock, as discussed below, is constituted by the presence in person or by proxy of the holders of record of a majority of the Preferred Shares entitled to vote at the AnnualSpecial Meeting. In the event that a quorum is not present at the AnnualSpecial Meeting or, in the event that a quorum is present but sufficient votes have not been received to approve any Board proposal, the AnnualSpecial Meeting may be adjourned to permit further solicitation of proxies. The presiding officer or Trustee of the Fund for the AnnualSpecial Meeting or the affirmative vote of a majority of the persons designated as proxies may adjourn the AnnualSpecial Meeting to permit further solicitation of proxies or for other reasons consistent with Delaware law and the Fund’s Declaration of Trust and Fourth Amended and RestatedBy-Laws. Unless otherwise instructed by

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a shareholder granting a proxy, the persons designated as proxies may use their discretionary authority to vote on questions of adjournment.

The Fund’s most recent Annual Report, including audited financial statements for the fiscal yearperiod ended JulyMarch 31, 2017,2018, has been mailed to shareholders and is also available upon request without charge by writing to the Fund at the address set forth above or by calling the Fund at1-877-848-4140. To reduce

PROPOSAL 1:     ELECTION

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expenses, only one copy of the proxy materials will be mailed to those addresses shared by two or more accounts. If you wish to revoke this arrangement and receive individual copies, you may do so at any time by writing to the address or calling the phone number set forth above. The Fund will begin sending you individual copies promptly after receiving your request.

PROPOSAL:

LIQUIDATION AND DISSOLUTION OF TRUSTEESTHE FUND

At a meeting of the Board held on May 10, 2018, the Trustees approved a proposal to liquidate and dissolve the Fund (the proposed liquidation and dissolution, the “Liquidation”) pursuant to a Plan of Liquidation and Dissolution (the “Plan”), a form of which is attached to this Proxy Statement as Exhibit A, subject to the approval of the Fund’s shareholders at the Special Meeting. Under the Fund’s Charter, the Liquidation requires the affirmative vote of the lesser of (i) more than 50% of the votes entitled to be cast by the holders of the Fund’s common shares and holders of the Fund’s preferred shares, voting together as a single class, or (ii) 67% or more of the Fund’s common shares and preferred shares present at the Special Meeting, voting as a single class, if the holders of more than 50% of the outstanding voting securities of the Fund are present or represented by proxy. At the Special Meeting, shareholders will be asked to approve the Liquidation and the Plan, which are described in this Proxy Statement. The Trustees unanimously recommend that you voteFOR the Liquidation.

Background

The Fund, a Delaware statutory trust organized under the laws of Delaware, commenced operations in 2003. The Fund’s investment objective is to provide shareholders with high current income exempt from regular Federal income tax while seeking to protect the value of the Fund’s assets during periods of interest rate volatility. As of April 13, 2018, the Fund had net assets totaling $98.5 million attributed to shares of common stock, in addition to approximately $60 million attributed to shares of preferred stock. Although the Fund has had a relatively small asset size since its inception, the Fund’s shareholder base has changed significantly over the past few years. As of April 13, 2018, several institutional shareholders (including activist investors and institutions that tend to support activist investors in any vote) owned approximately 44.32% of the Fund’s common shares.¹ One of these investors submitted several proposals for the 2018 Annual Meeting of Shareholders including a proposal to terminate the investment advisory agreement between the Fund and the Adviser (defined below). In connection with a standstill agreement with the Adviser, this shareholder agreed to withdraw the termination proposal, based, in part, on the Fund’s intention to present shareholders with the opportunity to vote on the Liquidation pursuant to the Plan. The Board also considered the potential costs and other consequences to the Fund and its shareholders of contesting proposals submitted by activist investors, or implementing them if approved by shareholders. The Board and the Adviser believe that continued or increasing ownership of the Fund by these large institutional and activist investors will have significant adverse consequences for the Fund. In addition to these changes in the Fund’s shareholder base, in recent years, the Fund’s shares have traded at a discount to their net asset value (“NAV”). For the years ended March 31, 2018, 2017 and 2016, the average discount was -7.55%, -6.90% and -9.67%, respectively. The Board has considered, and discussed with management of the Fund, a variety of measures designed to reduce or eliminate the discount and the influence of large institutional or activist investor base. These measures included, in addition to liquidation, merging the Fund with another fund affiliated with Cutwater Investor Services Corp., d/b/a Insight Investment, the Fund’s investment adviser (the “Adviser”), converting the Fund to anopen-end fund and commencing a significant tender offer. However, the Board concluded that it would not be advisable to implement any of these alternative measures for the reasons summarized below under “Board Considerations in Approving the Proposed Liquidation.”

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The Board believes that the Fund’s historical performance and distribution history have delivered significant value to shareholders since the Fund’s inception. However, having considered the Fund’s size, increasingly significant ownership of the Fund by institutional and activist investors (and the potential effects of such ownership), the recent trading discount, and the opportunity for shareholders to realize full NAV for their common shares through the Liquidation, Fund management and the Board determined that, on balance, liquidation and dissolution would be in the best interests of the Fund and its shareholders. In light of this conclusion, and after careful deliberation, the Board declared advisable, approved, and recommended that Fund shareholders approve the liquidation and dissolution of the Fund.

Board Considerations in Approving the Proposed Liquidation

In determining that the Liquidation is in the best interests of the Fund and its shareholders, and in approving, and recommending that shareholders approve the Liquidation and the Plan, the Board considered, among other factors:

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In addition, the Adviser discussed with the Board its view that while a tender offer might result in a further reduction in the discount in the short term, it is unlikely to have a lasting effect.

Following discussions with management, the Board, including all of the Trustees who are not “interested persons” (as that term is defined in the 1940 Act) of the Fund (the “Independent Trustees”), with the advice and assistance of counsel, approved the Liquidation and the Plan, and directed that they be submitted for the vote of the Fund’s shareholders. If the Liquidation is approved at the Special Meeting, management, under the oversight of the Board and officers of the Fund, will proceed to wind up the Fund’s affairs as soon as reasonably practicable thereafter in a timeframe that allows for an orderly liquidation of portfolio holdings. The Fund cannot predict at this time how long it will take to accomplish an orderly liquidation under then-existing market conditions. If the Liquidation is not approved by shareholders, the Trustees will consider whether another course of action would benefit the Fund and its shareholders.

Summary of the Plan

If the Liquidation is approved by shareholders, the liquidation and dissolution of the Fund would be effected in accordance with the terms of the Plan, which has been approved by the Board and is summarized below. This summary is not complete, and is qualified in its entirety by reference to the Plan, a form of which is attached to this Proxy Statement as Exhibit A. Shareholders are urged to read the Plan in its entirety.

Effective Date and Cessation of the Fund’s Activities as an Investment Company. If approved by shareholders at the Special Meeting, the Plan will become effective at the close of business on or about July 16, 2018 (the

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“Effective Date”) or, in the event the Special Meeting is postponed or adjourned, the Effective Date of the Plan shall be the date that the Liquidation meets the required vote for approval. After the Effective Date, the Fund will cease its business as an investment company and will not engage in any business activities except for the purpose of winding up its business and affairs, preserving the value of its assets, discharging or making reasonable provision for the payment of all of the Fund’s liabilities, including any contingent liabilities, and distributing its remaining assets to shareholders in accordance with the Plan. The Fund is unable to predict when a complete liquidation of its portfolio holdings will be accomplished.

Closing of Books and Transfer and Trading of Shares. For purposes of determining the shareholders of the Fund entitled to receive payment of all Liquidating Distributions, the proportionate interests of shareholders in the assets of the Fund shall be fixed on the basis of their respective shareholdings at the close of business on the Effective Date, or on such later date as may be determined by the Board (the “Preferred Shareholders”“Determination Date”). On the Determination Date, the books of the Fund shall be closed. Thereafter, unless the books of the Fund are reopened because the Plan cannot be carried into effect under the laws of the State of Delaware or otherwise, the shareholders’ respective interests in the Fund’s assets will not be transferable by the negotiation of share certificates, and shares of the Fund’s common stock will cease to be traded on the New York Stock Exchange (the “NYSE”). Prior to the Effective Date, the NYSE may remove the Fund’s shares from listing at any time if an event shall occur or conditions exist that, in the opinion of the NYSE, make further dealings on the NYSE inadvisable. The Fund expects that the shares will continue trading on the NYSE until the Effective Date and will not trade thereafter.

Liquidating Distributions. Within a reasonable period after the Effective Date, the Fund will determine, and pay or provide for the payment of, all charges, taxes, expenses, liabilities and reserves, whether due or accrued or anticipated, of the Fund. Such liabilities and expenses of the Fund will include the costs relating to the Liquidation, which are estimated to be approximately $75,000. The costs relating to the Liquidation are not expected to have equal voting rights (i.e., one vote per share)a material effect on the liquidating distributions to shareholders. As soon as reasonably practicable after the Determination Date and following the payment or other provision for all liabilities and expenses of the Fund, the remaining assets of the Fund will be distributed to, or for the account of, first, the Preferred Shareholders, and second, after determination of any dividend to be paid pursuant to the Plan, the Common Shareholders (each distribution, a “Liquidating Distribution”).

In accordance with the Fund’s common shareholdersstatement establishing and fixing the rights and preferences of Variable Rate MuniFund Term Preferred Shares (the “Common Shareholders”“Statement of Preferences”) and, except as shown in, Preferred Shareholders are entitled to receive $100,000 per preferred share, plus an amount equal to all accumulated but unpaid dividends on such preferred shares (whether or not earned or declared), upon the summary chart below, will vote together withliquidation, dissolution or winding up of the Common Shareholders as a single class on all proposalsaffairs of the Fund. In the event that the assets of the Fund available for distribution to be brought before the Annual Meeting. As summarized below, the Preferred Shareholders votingare insufficient to pay in full the amounts to which the Preferred Shareholders are entitled under the Statement of Preferences, then payment will be made ratably in proportion to the respective preferential liquidation amounts to which they are entitled. After Liquidating Distributions have been made to all Preferred Shareholders, the Fund’s remaining assets will be distributed to Common Shareholders in one or more cash payments in complete liquidation of the Fund.

Shareholders will receive information concerning the sources of the Liquidating Distribution. Upon filing of the Certificate of Cancellation, all outstanding shares of the Fund will be deemed cancelled.

Deregistration under the 1940 Act. As soon as practicable after the Effective Date and the completion of the implementation of the Plan, steps will be taken to deregister the Fund as an investment company under the 1940 Act.

Other Actions. The officers of the Fund will take such other actions as may be deemed necessary or advisable to carry out the provisions and purposes of the Plan.

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Federal Tax Consequences

The following is only a general summary of the significant United States federal income tax consequences of the Plan to the Fund and its shareholders and is limited in scope. This summary is based on the federal tax laws and applicable Treasury regulations in effect on the date of this Proxy Statement, all of which are subject to change by legislative or administrative action, possibly with retroactive effect. The Fund has not sought a ruling from the Internal Revenue Service (the “IRS”) with respect to the federal income tax consequences to the Fund or its shareholders that will result from the Fund’s liquidation. The statements below are not binding upon the IRS or a court, and there is no assurance that the IRS or a court will not take a view contrary to those expressed below.

The summary applies only to beneficial owners of the Fund’s common shares in whose hands such shares are capital assets within the meaning of Section 1221 of the Code, and may not apply to certain types of beneficial owners of the Fund’s shares, including, but not limited to insurance companies,tax-exempt organizations, shareholders holding the Fund’s shares throughtax-advantaged accounts (such as an individual retirement account (an “IRA”), a 401(k) plan account, or other qualified retirement account), financial institutions, pass-through entities, broker-dealers, entities that are not organized under the laws of the United States or a political subdivision thereof, persons who are neither a citizen nor resident of the United States, shareholders holding the Fund’s shares as part of a hedge, straddle or conversion transaction, and shareholders who are subject to the alternative minimum tax. Persons who may be subject to tax in more than one country should consult the provisions of any applicable tax treaty to determine the potential tax consequences to them.

If an entity or arrangement treated as a separate class, havepartnership for U.S. federal income tax purposes holds the right to voteFund’s common stock, the U.S. federal income tax treatment of a partner in such partnership generally will depend on the electionstatus of the Trustees designatedpartner and the activities of such partnership. A partner of a partnership holding the Fund’s common stock should consult its own tax advisor regarding the U.S. federal income tax consequences to represent the Preferred Shares. Ms. Welsh and Mr. Spock are each onepartner of the two Trustees designatedFund’s Liquidating Distribution.

For purposes of the following discussion, “U.S. Shareholder” is a shareholder that is (i) a citizen or resident of the United States, (ii) a corporation (or other entity taxable as a corporation) created or organized under the laws of the United States or any state thereof or the District of Columbia, (iii) an estate, the income of which is subject to representU.S. federal income taxation regardless of its source, or (iv) a trust if (a) a U.S. court can exercise primary supervision over the Preferredtrust’s administration and one or more U.S. persons are authorized to control all substantial decisions of the trust or (b) it has a valid election in effect under applicable Treasury regulations to be treated as a U.S. person. A“Non-U.S. Shareholder” is a person that is neither a U.S. shareholder nor an entity treated as a partnership for U.S. federal income tax purposes.

This summary addresses significant federal income tax consequences of the Plan, but does not discuss foreign, state or local tax consequences of the Plan. Implementing the Plan may impose unanticipated tax consequences on shareholders or affect shareholders differently, depending on their individual circumstances. Shareholders are encouraged to consult with their own tax advisors to determine the particular tax consequences that may be applicable in connection with the Plan.

If the Liquidation is approved by shareholders and the Fund proceeds to liquidate and dissolve, the Fund intends to continue to satisfy all of the qualification requirements for taxation as a regulated investment company under Subchapter M of the Code, for its final taxable year. Accordingly, the Fund expects that it will not be taxed on any capital gains realized from the sale of the Fund’s assets or ordinary income that the Fund timely distributes to shareholders. Prior to making Liquidating Distributions to shareholders, the Fund intends to declare dividends necessary to satisfy the income and excise tax distribution requirements for its final taxable year, and to make any such distribution either prior to or at the time of the Liquidating Distributions.

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U.S. Shareholders. Common Each shareholder who receives a Liquidating Distribution will generally recognize gain (or loss) for federal income tax purposes equal to the amount by which the amount of the Liquidating Distribution exceeds (or is less than) the shareholder’s adjusted tax basis in its, his or her liquidating Fund shares. Any gain or loss realized by a shareholder on the Liquidating Distribution generally will be treated as long-term capital gain or loss if the shareholder’s Fund shares have been held for more than 12 months. If the shareholder’s Fund shares have been held by the shareholder for 12 months or less, the gain or loss on the Liquidating Distributions will be treated as short-term capital gain or loss.

The Fund is generally required to withhold and remit to the U.S. Treasury a percentage of the taxable liquidation proceeds paid to any shareholder who fails to provide the Fund with a correct taxpayer identification number, who has underreported dividend or interest income, or who fails to certify to the Fund that he, she or it is not subject to backup withholding.

Non-U.S. Shareholders. The U.S. federal income taxation of aNon-U.S. Shareholder of the Liquidating Distribution depends on whether this transaction is “effectively connected” with a trade or business carried on in the United States (“U.S.”) by theNon-U.S. Shareholder (and if an income tax treaty applies, on whether theNon-U.S. Shareholder maintains a U.S. permanent establishment). If the Liquidating Distribution is not effectively connected with a U.S. trade or business (or, if an income tax treaty applies, theNon-U.S. Shareholder does not maintain a U.S. permanent establishment), any gain realized by aNon-U.S. Shareholder upon the Liquidation will not be subject to U.S. federal income tax or to any U.S. tax withholding; provided, however, that such gain will be subject to U.S. federal income tax at the rate of 30% (or such lower rate as may be applicable under an income tax treaty) if theNon-U.S. Shareholder is anon-resident alien individual who is physically present in the United States for more than 182 days during the taxable year of the sale.

If the amount realized by aNon-U.S. Shareholder is effectively connected with the conduct of a trade or business in the United States by theNon-U.S. Shareholder (and, if an income tax treaty applies, theNon-U.S. Shareholder maintains a U.S. permanent establishment), the transaction will be treated and taxed in the same manner as if the Liquidating Distribution involved a U.S. Shareholder.

Non-U.S. Shareholders should provide the Trust with a properly completed FormW-8BEN, FormW-8BEN-E, FormW-8IMY, FormW-8ECI or other applicable form in order to avoid backup withholding on the Liquidating Distribution.

The tax discussion set forth above is included for general information only. Each shareholder is urged to consult such shareholder’s own tax advisor to determine the particular tax consequences to him, her or it of the Liquidation, including the applicability and effect of foreign, state and local tax laws.

Impact of the Plan on the Fund’s Status under the 1940 Act and State Law

As noted above, the Plan provides that, on the Effective Date, the Fund will cease doing business as a registered investment company and, as soon as practicable, will apply for deregistration under the 1940 Act. A vote in favor of the Liquidation will constitute a vote in favor of the Fund’s deregistration under the 1940 Act. Until the Fund’s deregistration as an investment company becomes effective, the Fund, as a registered investment company, will continue to be subject to the 1940 Act.

After the Effective Date, a Certificate of Cancellation will be executed, acknowledged and filed with the State of Delaware, and will become effective in accordance with the Delaware Statutory Trust Act. Upon the effective date of such, the Fund will be legally dissolved, but thereafter the Fund will continue to exist for the purpose of paying, satisfying, and discharging any existing debts or obligations, collecting and distributing its assets, and doing all other acts required to liquidate and wind up its business and affairs, but not for the purpose of continuing the business for which the Fund was organized.

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Appraisal Rights

Shareholders will not participatebe entitled to appraisal rights under Delaware law in connection with the Plan.

The Board, including the Independent Trustees, unanimously recommends that shareholders vote “FOR” the proposed Liquidation.

PROXY VOTING AND SHAREHOLDER MEETING

All properly executed and timely received proxies will be voted at the Special Meeting in accordance with the instructions marked thereon or as otherwise provided therein. If no specification is made on a properly executed proxy, it will be voted for the matters specified on the Proxy Card in the electionmanner recommended by the Board. Accordingly, unless instructions to the contrary are marked on the proxies, all properly executed and timely received proxies will be cast in favor of Ms. Welsh and Mr. Spock. The electionthe Liquidation. Any shareholder may revoke that shareholder’s proxy at any time prior to exercise thereof by submitting a written notice of Ms. Harvey will requirerevocation or subsequently executed proxy to the Secretary of the Fund before or at the Special Meeting or voting in person at the Special Meeting.

Properly executed proxies may be returned with instructions to abstain from voting or to withhold authority to vote (an “abstention”) or may represent a broker“non-vote” (which is a proxy from a broker or nominee indicating that the broker or nominee has not received instructions from the beneficial owner or other person entitled to vote shares on a particular matter with respect to which the broker or nominee does not have discretionary power to vote). Approval of the Liquidation requires the affirmative vote of a majority of the votes ofentitled to be cast by the CommonPreferred Shareholders and the PreferredCommon Shareholders voting together as a single class,class. Any abstention or broker non-vote will be considered present for purposes of determining the Fund cast forexistence of a quorum but will have the election of Trustees at the Annual Meeting, in person or by proxy.

The Fund’s Board of Trustees is presently comprised of five (5) Trustees. The Board is divided into three classes, and members of each class hold office for a term of three years or until their successors are elected and qualified. The term of one class expires in each year. At the Annual Meeting of Shareholders held on November 16, 2016, the Fund’s shareholders elected each of the current Trustees to staggered terms in accordance with the Declaration of Trust. Accordingly, the term of office of only a single class of Trustees will expire in 2017. The effect of these staggered terms is to limita vote against the ability of other entities or persons to acquire control of the Fund by delaying the replacement ofLiquidation. If any such procedural matter requiring a majority of the Board.

The term of office of the Class I Trustees, if elected at this Annual Meeting, will expire at the annual meetingvote of shareholders to be held in 2020, or thereafter when their respective successors are duly elected. The term of office of the Class II Trustee expires at the annual meeting of shareholders to be held in 2018, or thereafter when his successor is duly elected. The term of office of the Class III Trustees, including Mr. Spock, expires at the annual meeting of shareholders to be held in 2019, or thereafter when their respective successors are duly elected.

The Trustees to be elected at the Annual Meeting are to hold office until their successors shall have been elected and shall have qualified. Except as otherwise directed on the proxy card, it is the intention of the persons named on the proxy card to vote FOR the election of the trustees named below, each of whom has consented to being named in this proxy statement and to serve if elected. If any of the nominees is unavailable to serve for any reason,should arise, the persons named as proxies will vote on such procedural matter in accordance with their discretion.

A quorum for suchthe Special Meeting will consist of the presence in person or by proxy of the holders of a majority of the total outstanding shares of the Fund’s common and preferred shares. In the event that (i) a quorum is not present at the Special Meeting; or (ii) a quorum is present but sufficient votes in favor of the position recommended by the Board for the Liquidation (as described in this Proxy Statement) have not been timely received, the Chairman of the Special Meeting may authorize, or the persons named as proxies may propose and vote for, one or more adjournments of the Special Meeting, with no other nomineenotice than an announcement at the Special Meeting, in order to permit further solicitation of proxies. Shares represented by proxies indicating a vote contrary to the position recommended by the Board will be voted against adjournment of the Special Meeting.

The Fund has engaged Georgeson LLC, to assist in soliciting proxies for the Special Meeting. Georgeson LLC will receive a total fee of approximately $5,000, plus $6.50 per completed telephone call to shareholders in the event that active solicitation is required, and the Fund will reimburse its expenses. The cost of solicitation will be borne by the Fund. The Fund expects that the solicitation will be primarily by mail, but also may include telephone, electronic, oral or nominees nominatedother means of communication. If the Fund does not receive your proxy by those Trustees who are not “interested persons”a certain time, you may receive a telephone call from a proxy soliciting agent asking you to vote. Officers of the Fund, or employees of Fund management, may also be involved in the solicitation of proxies.

Stock Ownership

The outstanding voting shares of the Fund as defined in the Investment Company Act of 1940, as amended (“1940 Act”). The Fund currently knows of no reason why any of the trustees listed below would be unable or unwilling to serve if elected. OfficersRecord Date consisted of 6,800,476 shares of the Trust serve until death, resignation or removal. Certain information regarding eachFund’s Common Shares and 600 shares of the nominees as well asFund’s Series 2020 Variable Rate MuniFund Term Preferred Shares.

As of the currentRecord Date, the Trustees and executive officers of the Fund, is set forth below. Unless otherwise noted,both individually and as a group, owned less than 1% of the mailing addressshares of each Trustee and executive officerthe Fund. During the Fund’s most recently completed fiscal year, the Fund’s Trustees as a group did not engage in the purchase or sale of more than 1% of any class of securities of the Adviser or of any of its parents or subsidiaries.

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INFORMATION AS TO THE INVESTMENT ADVISER AND THE ADMINISTRATOR OF THE FUND

The Fund’s investment adviser is c/o Cutwater Investor Services Corp. d/b/a Insight Investment, (herein referred to as “Insight” or the “Adviser”), 200 Park Avenue, 7th Floor, New York, NYNew York 10166.

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Current Officers

Additional Information Concerning The Adviser also functions as the Board of Trustees

The Board believes that each Trustee’s experience, qualifications, attributes or skills on an individual basis and in combination with those of the other Trustees leadadministrator to the conclusion that the Board possesses the requisite

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skills and attributes. The Board believes that the Trustees’ ability to review, critically evaluate, question and discuss information provided to them, to interact effectively with Insight, as investment adviser to the Fund, other service providers, counsel and independent auditors, and to exercise effective business judgment in the performance of their duties, support this conclusion.

Mr. Corso is an “interested person” (as defined in the 1940 Act) by virtue of his position at Insight. Each Trustee of the Fund, excluding Mr. Corso, is not an “interested person” of the Fund (such Trustees who are not interested persons of the Fund being referred to as the “Independent Trustees”).

Trustee Qualification

The following is a brief discussion of the experience, qualifications, attributes and/or skills that led to the Board of Trustees’ conclusion that each individual identified below is qualified to serve as a Trustee of the Fund. In determining that a particular Trustee was qualified to serve as a Trustee, the Board has considered a variety of criteria, none of which was controlling. The Board believes that the Trustees’ ability to review critically, evaluate, question and discuss information provided to them, to interact effectively with the Adviser, other service providers, counsel and independent auditors, and to exercise effective business judgment in the performance of their duties, support the conclusion that each Trustee is qualified to serve as a Trustee of the Fund.

In addition, the following specific experience, qualifications, attributes and/or skills apply as to each Trustee: Mr. Brown, business, accounting and finance expertise and experience as a president, board member and/or executive officer of various businesses; Ms. Harvey, business and finance expertise and experience as a senior vice president, chairperson, principal and/or board member of various businesses andnon-profit and other organizations; Mr. Spock, business and finance expertise and experience as an executive vice president, vice president and chief financial officer of various businesses; Ms. Welsh, business, finance and accounting expertise and experience as a college treasurer and chief financial officer; and Mr. Corso , business, finance, regulatory and investment matters and experience as the Chief Executive Officer of Insight North America and previously, Chief Investment Officer of Insight. Each Trustee and nominee also has considerable familiarity with Insight and other service providers, and their operations, as well as the special regulatory requirements governing regulated investment companies and the special responsibilities of investment company trustees as a result of substantial prior service as a Trustee of a fund, as applicable.

References to the qualifications, attributes and skills of Trustees are pursuant to requirements of the Securities and Exchange Commission (“SEC”), do not constitute holding out of the Board or any Trustee as having any special expertise or experience, and shall not impose any greater responsibility or liability on any such person or on the Board by reason thereof.

The Board has determined that its leadership structure is appropriate given the business and nature of the Fund. The Chairman of the Board is an Independent Trustee. The Chairman’s primary role is to participate in the preparation of the agenda for meetings of the Board of Trustees and the identification of information to be presented to the Board with respect to matters to be acted upon by the Board of Trustees. The Chairman also presides at all meetings of the Board of Trustees and acts as a liaison with service providers, officers, attorneys and other Trustees generally between meetings. The Chairman may perform such other functions as may be requested by the Board of Trustees from time to time. Except for any duties specified herein or pursuant to the Trust’s Declaration of Trust orBy-Laws, the designation of Chairman does not impose on such Independent Trustee any duties, obligations or liability that is greater than the duties, obligations or liability imposed on such person as a member of the Board, generally.

The Board also considered that the chairperson of each Board committee is an Independent Trustee, which yields similar benefits with respect to the functions and activities of the various Board committees. Through the committees, the Independent Trustees consider and address important matters involving the Fund, including

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those presenting conflicts or potential conflicts of interest for management. The Independent Trustees also regularly meet outside the presence of management with counsel to the Fund. The Board has determined that its committees help ensure that the Fund has effective and independent governance and oversight. The Board also believes that its leadership structure facilitates the orderly and efficient flow of information to the Independent Trustees from Fund management.

Trustees Attendance At Meetings

The Board held eight meetings during the Fund’s fiscal year ended July 31, 2017. All Independent Trustees attended 100% of all meetings of the Board and each committee of which they were members. Each Trustee attended at least 75% of the aggregate number of meetings of the Board and the committees for which he was eligible. The Fund does not have a written policy regarding attendance by Trustees at annual meetings of shareholders although Trustees are encouraged to attend annual meetings of shareholders.

The Board has an Audit Committee and a Nominating and Governance Committee that meet periodically during the year and whose responsibilities are described below.

Board’s Role in Risk Oversight

Consistent with its responsibility for oversight of the Fund, the Board, among other things, oversees risk management of the Fund’s investment program and business affairs directly and through the committee structure it has established. The Board has established the Audit Committee and the Nominating and Governance Committee to assist in its oversight functions, including its oversight of the risks the Fund faces. Each committee reports its activities to the Board on a regular basis. Risks to the Fund include, among others, investment risk, credit risk, liquidity risk, valuation risk and operational risk, as well as the overall business risk relating to the Fund. The Board has adopted, and periodically reviews, policies, procedures and controls designed to address these different types of risks. Under the Board’s supervision, the officers of the Fund, Insight and other service providers to the Fund, as applicable, also have implemented a variety of processes, procedures and controls to address various risks. In addition, as part of the Board’s periodic review of the Fund’s advisory and other service provider agreements, the Board may consider risk management aspects of the service providers’ operations and the functions for which they are responsible.

The Board requires officers of the Fund to report to the full Board on a variety of matters at regular and special meetings of the Board and its committees, as applicable, including matters relating to risk management. The Audit Committee also receives reports from the Fund’s independent registered public accounting firm on internal control and financial reporting matters. Typically, on at least a quarterly basis, the Board meets with the Fund’s Chief Compliance Officer, including separate meetings with the Independent Trustees in executive session, to discuss compliance matters and, on at least an annual basis, receives a report from the Chief Compliance Officer regarding the effectiveness of the Fund’s compliance program. The Board, with the assistance of Fund management, reviews investment policies and risks in connection with its review of the Fund’s performance. In addition, the Board receives reports from Insight on the investments and securities trading of the Fund. With respect to valuation, the Board oversees a pricing committee comprised of Insight personnel and has approved valuation and pricing procedures applicable to valuing the Fund’s securities, which the Board and its Audit Committee periodically review. The Board also requires Insight to report to the Board on other matters relating to risk management on a regular andas-needed basis.

Role of Diversity in Considering Board Candidates

In considering Trustee nominee candidates, the Nominating and Governance Committee takes into account a wide variety of factors, including the overall diversity of each Board’s composition. The Nominating and Governance Committee believes the Board generally benefits from diversity of background, experience and views among its members, and considers this a factor in evaluating the composition of the Board, but has not adopted any specific policy in this regard.

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Trustees’ Prior Legal and Disciplinary Actions

The Trustees, including the nominees, have no prior legal or disciplinary actions.

Board Committees and Meetings

The Board is responsible for ensuring that the Fund is managed in the best interest of its shareholders. The Trustees oversee the Fund’s business by, among other things, meeting with the Fund’s management and evaluating the performance of the Fund’s service providers including Insight and BNY Mellon and certain of its affiliates. As part of this process, the Trustees consult with the Fund’s independent registered public accounting firm and with their independent legal counsel.

Audit Committee

The Audit Committee of the Board currently consists of Mr. Brown, Ms. Harvey, Mr. Spock and Ms. Welsh, each of whom is an “independent” member of the Board, as that term is defined by the New York Stock Exchange’s listing standards, and also a“non-interested person” as that term is defined in the 1940 Act. Ms. Welsh serves as the Chairperson of the Audit Committee. The Board has determined that Ms. Welsh qualifies as an “audit committee financial expert” as such term is defined in Item 3 of FormN-CSR.

The Audit Committee is, among other things, responsible for: (i) overseeing the Fund’s accounting and financial reporting policies and practices, its internal controls over financial reporting and the quality, integrity and objectivity of the Fund’s financial statements and the independent audit thereof, (ii) approving prior to appointment the engagement of the Fund’s independent registered public accounting firm, (iii) selecting, overseeing and approving the compensation of the Fund’s independent registered public accounting firm, and (iv) discussing the Fund’s annual audited financial statements and semi-annual financial statements with management and the independent registered public accounting firm.

The Audit Committee reviews the scope of the audit by the Fund’s independent accountants, confers with the independent accountants with respect to the audit and the internal accounting controls of the Fund and with respect to such other matters as may be important to an evaluation of the audit and the financial statements of the Fund. The Audit Committee also selects and retains the independent accountants for the Fund. During the fiscal year ended July 31, 2017, the Audit Committee held four meetings. The Board has adopted a written charter for the Audit Committee (the “Audit Committee Charter”), the most recent version of which was approved by the Board on May 10, 2017. The Fund’s Audit Committee Charter is attached hereto as Exhibit A.

Nominating and Governance Committee

The Nominating and Governance Committee, the principal functions of which are to select and nominate persons for election as Trustees of the Fund and to oversee certain corporate governance matters of the Fund, is currently composed of Mr. Brown, Ms. Harvey, Mr. Spock and Ms. Welsh. Ms. Harvey serves as the Chairperson of the Nominating and Governance Committee. Only Trustees who are not “interested persons” of the Fund as defined in the 1940 Act and who are “independent” as defined in the NYSE listing standards are members of the Nominating and Governance Committee. The Nominating and Governance Committee may accept nominees recommended by the shareholders as it deems appropriate. Shareholders who wish to recommend a nominee should send nominations that include biographical data and set forth the qualifications of the proposed nominee to the Fund’s Secretary. The Nominating and Governance Committee held two meetings during the last fiscal year. During the fiscal year ended July 31, 2017, four new Independent Trustee nominees and one continuing Trustee nominee were recommended to, or approved by, the Nominating and Governance Committee.

The Nominating and Governance Committee is governed by a written charter, the most recent version of which was approved by the Board on December 7, 2016 (the “Nominating and Governance Committee Charter”).

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The Nominating and Governance Committee identifies potential nominees through its network of contacts and may also engage, if it deems appropriate, a professional search firm. While the Nominating and Governance Committee meets to discuss and consider such candidates’ qualifications and then chooses a candidate by majority vote, the Nominating and Governance Committee does not have specific, minimum qualifications for nominees and has not established specific qualities or skills that it regards as necessary for one or more of the Fund’s Trustees to possess (other than any qualities or skills that may be required by applicable law, regulation or listing standards). However, as set forth in the Nominating and Governance Committee Charter, the Nominating and Governance Committee may consider the following factors in evaluating a person as a potential nominee to serve as a Trustee of the Fund, among any others it may deem relevant:

Following an initial evaluation by the Committee, a nominee must:

Shareholder Communications with Trustees

Shareholders and other interested parties may contact the Board or any member of the Board by mail. To communicate with the Board or any member of the Board correspondence should be addressed to the Board or the Board members with whom you wish to communicate by either name or title. All such correspondence should be sent to the principal place of business of the Fund, c/o Managed Duration Investment Grade Municipal Fund, 200 Park Ave, 7th Floor, New York, NY 10166.

Trustee and Executive Officer Compensation

Insight or its affiliates pay all compensation of officers and employees of the Fund who are affiliated persons of BNY Mellon or its subsidiaries.

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The Fund pays each Independent Trustee a combined fee of $1,250 per quarter for services on the Board and on the committees. Additionally, the Fund pays each Independent Trustee a fee of $1,000 per Board meeting and $500 per committee meeting (half of these amounts if the meetings are held telephonically). The Chairperson of the Board, so long as he or she is an Independent Trustee, receives an additional $4,500 per year for his service, and the Chairperson of each of the Audit Committee and the Nominating and Governance Committee receives an additional $1,500 per year for his or her service. The Fund reimburses each Independent Trustee for his or herout-of-pocket expenses relating to attendance at Board and committee meetings. The Fund does not accrue or pay retirement or pension benefits to Trustees as of the date of this proxy statement.

The aggregate compensation paid by the Fund to each of its Trustees serving during the fiscal year ended July 31, 2017 is set forth in the compensation table below. The Fund’s four Independent Trustees serve on the Board of another registered investment company to which the Fund’s investment adviser or an affiliated person of the Fund’s investment adviser provides investment advisory services.

Ownership of Fund Securities

The following table includes the ownership of Fund shares by the Trustees of the Fund as of the Record Date.

None of the Independent Trustees, and no immediate family member of any Independent Trustee, owns securities of the Fund’s investment adviser, or any control person of the Fund’s investment adviser. As of the Record Date, the Trustees and executive officers (7 persons) beneficially owned an aggregate of less than 1% of the Fund’s outstanding shares.

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Required Vote

The election of Ms. Welsh and Mr. Spock to the Board of Trustees will require the affirmative vote of a majority of the Preferred Shares (voting as a separate class) present and entitled to vote for the election of Trustee at the Meeting, in person or by proxy. The election of Ms. Harvey to the Board of Trustees will require the affirmative vote of a majority of the Common Shares and Preferred Shares (voting together as a single class) present and entitled to vote for the election of Trustees at the Meeting, in person or by proxy.

Brokernon-votes (i.e., shares held by brokers or nominees, typically in “street name,” as to which proxies have been returned but instructions have not been received from the beneficial owners or persons entitled to vote, and the broker or nominee does not have discretionary voting power on a particular matter) will not be counted as shares present for quorum purposes with respect to such matters. Assuming the presence of a quorum, votes withheld and abstentions will have the same effect as votes against the Proposal and brokernon-votes will have no effect on the vote on the Proposals.

THE TRUSTEES, INCLUDING THE TRUSTEES WHO ARE NOT “INTERESTED PERSONS,” UNANIMOUSLY RECOMMEND THAT THE SHAREHOLDERS VOTE “FOR ALL” THE NOMINEES FOR TRUSTEE.

Expenses of Proxy Solicitation

The Fund will bear all costs in connection with the solicitation of proxies for the Annual Meeting. Certain officers of the Fund and certain officers and employees of Insight or its affiliates (none of whom will receive additional compensation therefore) or BNY Mellon or its affiliates (none of whom will receive additional compensation therefore), may solicit proxies by telephone, mail,e-mail and personal interviews. Brokerage houses, banks and other fiduciaries may be requested to forward proxy solicitation material to their principals to obtain authorization for the execution of proxies, and will be reimbursed by the Fund for suchout-of-pocket expenses.

ADDITIONAL INFORMATION

Information Regarding the Fund’s Independent Registered Public Accounting Firm

Tait, Weller & Baker LLP (“Tait Weller”), 1818 Market Street, Suite 2400, Philadelphia, Pennsylvania 19103, has been selected to serve as the Fund’s independent accountants for the Fund’s fiscal year ending July 31, 2018. Tait Weller acted as the Fund’s independent accountants for the fiscal year ended July 31, 2017. The Fund knows of no direct financial or material indirect financial interest of Tait Weller in the Fund. A representative of Tait Weller will not be present at the Annual Meeting, but will be available by telephone and will have an opportunity to make a statement, if asked, and will be available to respond to appropriate questions.

Change in Independent Registered Public Accounting Firm

Effective March 8, 2017, Managed Duration Investment Grade Municipal Fund (the “Fund’’), by action of its Audit Committee, which was confirmed and approved by its Board of Trustees, selected Tait Weller & Baker LLP (“Tait Weller”) to succeed Ernst & Young LLP (“EY’’) as the independent registered public accounting firm to the Fund and to audit the Fund’s financial statements for the fiscal year ending July 31, 2017.

EY resigned as the independent registered public accounting firm to the Fund on March 8, 2017. EY’s reports on the Fund’s financial statements for the two most recent fiscal years ended July 31, 2016 and July 31, 2015, contained no adverse opinion or disclaimer of opinion nor were they qualified or modified as to uncertainty, audit scope or accounting principles. During the Fund’s two most recent fiscal years ended July 31, 2016 and July 31, 2015 and through March 8, 2017: (i) there were no disagreements with EY on any matter of

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accounting principles or practices, financial statement disclosure or auditing scope or procedure, which disagreements, if not resolved to the satisfaction of EY, would have caused it to make reference to the subject matter of the disagreements in connection with its reports on the Fund’s financial statements for such years; and (ii) there were no “reportable events’’ of the kind described in Item 304(a)(1)(v) of RegulationS-K under the Securities Exchange Act of 1934, as amended.

EY’s resignation does not reflect any disagreements with or dissatisfaction by the Fund or the Board of Trustees with the performance of the Fund’s prior independent registered public accounting firm, EY. During the Fund’s two most recent fiscal years, neither the Fund, nor anyone on their behalf, consulted with Tait Weller on items which: (i) concerned the application of accounting principles to a specified transaction, either completed or proposed, or the type of audit opinion that might be rendered on the Fund’s financial statements; or (ii) concerned the subject of a disagreement (as defined in paragraph (a)(1)(iv) of Item 304 of RegulationS-K) or reportable events (as described in paragraph (a)(1)(v) of said Item 304).

The Fund has requested that EY furnish it with a letter addressed to the Securities and Exchange Commission (“SEC”) stating whether EY agrees with the above statements with respect to EY. A copy of the letter from EY to the SEC was filed as an Exhibit to the Fund’s Form8-K, filed on March 16, 2017.

Report of the Audit Committee

The Audit Committee has reviewed and discussed the Fund’s audited financial statements for the fiscal year ended July 31, 2017 with Fund management. Further, the Audit Committee has discussed with Tait, Weller & Baker LLP (“Tait Weller”), the Fund’s independent registered public accounting firm, the matters required to be discussed by Public Company Accounting Oversight Board (“PCAOB”) Auditing Standard No. 16 (Communications with Audit Committees). The Audit Committee has received the written disclosures and a letter from Tait Weller required by PCAOB Rule 3526 (Communication with Audit Committees Concerning Independence) and has discussed with Tait Weller their independence. Based upon the foregoing, the Audit Committee recommended to the Board of Directors that the audited financial statements of the Fund be included in the Fund’s annual report to shareholders for filing with the U.S. Securities and Exchange Commission (“SEC”) for the fiscal year ended July 31, 2017. Additionally, the Audit Committee recommended that Tait Weller be appointed as the Fund’s independent registered public accounting firm for the fiscal year ending July 31, 2018.

Submitted by the Audit Committee of the Fund’s Board of Trustees

Suzanne P. Welsh, Chairperson

W. Thacher Brown

Ellen D. Harvey

Thomas E. Spock

Set forth in the table below are audit fees andnon-audit related fees billed charged by the Fund’s independent registered public accounting firms for professional services received during and for the Fund’s fiscal years ended July 31, 2016 and 2017, respectively.

Audit-Related Fees are fees related to assurance and related services related to the annual audit of the Fund and for review of the Fund’s financial statements, other than the Audit Fees described below. These include agreed upon procedures reports performed for rating agencies and the issuance of comfort letters. Tax Fees are fees associated with tax compliance, tax advice and tax planning, including federal, state and local income tax return preparation and related advice and determination of taxable income and miscellaneous tax advice. All Other Fees are fees related to products and services other than those services reported below under “Audit Fees,” “Audit-Related Fees” and “Tax Fees.”

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The Audit Committee is governed by the Audit Committee Charter, as discussed above. The Fund will provide for appropriate funding as determined by the Audit Committee, for payment of compensation to the independent public accountants and to any consultants, experts or advisors engaged by the Committee. The Fund’s Audit Committee charter requires that the Audit Committee shallpre-approve all auditing services and permittednon-audit services (including the fees for such services and terms thereof) to be performed for the Fund by its independent public accountants in one of two methods. Under the first method, the engagement to render the services would be entered into pursuant topre-approval policies and procedures established by the Audit Committee, provided (i) the policies and procedures are detailed as to the services to be performed, (ii) the Audit Committee is informed of each service, and (iii) such policies and procedures do not include delegation of the Audit Committee’s responsibilities under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) to the Fund’s management. Under the second method, the engagement to render the services would be presented to andpre-approved by the Audit Committee (subject to the de minimus exceptions fornon-audit services described in Section 10A(i)(1)(B) of the Exchange Act that are approved by the Audit Committee prior to the completion of the audit). The Chair of the Audit Committee has the authority to grantpre-approvals of audit and permissiblenon-audit services by the independent public accountants, provided that allpre-approvals by the Chair must be presented to the full Audit Committee at its next scheduled meeting. All of the audit, audit-related and tax services described above for which the Fund’s independent registered public accounting firm billed the Fund fees for the fiscal years ended July 31, 2016 and July 31, 2017 werepre-approved by the Audit Committee. These were the only services provided by the Fund’s independent registered public accounting firms.

Investment Adviser and Administrator

Cutwater Investor Services Corp. (d/b/a Insight Investment), 200 Park Ave, 7th Floor, New York, NY 10166, serves as the Fund’s investment adviser. BNY Mellon Investment Servicing (U.S.) Inc. provides certain administrative services to the Fund. Insight is a Delaware corporation and is an investment adviser registered under the Investment Advisers Act of 1940. Insight is an indirect wholly-owned subsidiary of The Bank of New York Mellon, which is a New York state-chartered bank that is regulated by the New York Department of Financial Services and is a member of the Federal Reserve System. The Bank of New York Mellon has principal offices at One Wall225 Liberty Street, New York, NY 10286. Bank of New York Mellon Corporation is the parent company of The Bank of New York Mellon.

SECTION 16(A) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE

The Fund is not aware of an untimely filing of a statement of initial beneficial ownership interest by any person subject to Section 16(a) Beneficial Ownership Reporting Compliance

Section 30(h) of the 1940 Act and Section 16(a) of16 under the Securities Exchange Act of 1934 requireduring the Fund’s executive officers, Trustees and 10% shareholders (collectively, “Reporting Persons”), to file with the SEC and the New York Stock Exchange initial reports of ownership and reports of changes in ownership of equity securities of the Fund. Reporting Persons are required by SEC regulations to furnish the Fund with copies of all Section 16(a) forms they file. To the Fund’s knowledge, based solely on review of the copies of such reports furnished to the Fund during the fiscal yearperiod ended JulyMarch 31, 2017, all reports required to be filed pursuant to Section 16(a) were filed on a timely basis, with the exception of two reports on Form 4 which were not filed on a timely basis with respect to share purchases by Ms. Harvey and Ms. Welsh. Each of Ms. Harvey and Ms. Welsh promptly notified the Fund of the share purchases; however, due to administrative oversight the reports were not timely submitted to the SEC.

11

Security Ownership of Certain OwnersSECURITY OWNERSHIP OF CERTAIN OWNERS

To the Fund’s knowledge, no person owned beneficially 5% or more of the outstanding commonCommon shares of the Fund as of the Record Date, except that, based on Schedule 13G and 13D filings, the following information with respect to beneficial ownership of more than 5% of the outstanding voting commonCommon shares has been reported:

Based on Schedule 13D filings, the following information with respect to beneficial ownership of more than 5% of the outstanding voting preferred shares has been reported as of the Record Date:

10

As of the Record Date, Cede & Co. held approximately 99.93%99.96% of the outstanding voting shares of the Fund. (Cede & Co. is the nominee name for The Depository Trust Company, a large clearing house that holds shares in its name for banks, brokers and institutions in order to expedite the sale and transfer of stock.)

Each Trustee’s individual shareholdings ofSUBMISSION OF PROPOSALS FOR THE NEXT ANNUAL MEETING OF STOCKHOLDERS

If the Liquidation is approved at the Special Meeting, the Fund constituted less than 1% ofdoes not intend to hold another annual meeting. However, if the outstanding shares ofLiquidation is not approved or has not commenced, the Fund and as a group, the Trustees and officers of the Fund owned less than 1% of the shares of the Fund.

Shareholder Proposals

will hold an annual meeting. All proposals by shareholders of the Fund that are intended to be presented at the Fund’s next annual meeting of shareholders to be held in 2018prior to the Fund’s fiscal year end of March 31, 2019 must be received by the Fund no earlier than August 8, 2018January 11, 2019 and no later than September 7, 2018.February 10, 2019. If a shareholder who wishes to present a proposal fails to notify the Fund by this date, the proxies solicited for the meeting will have discretionary authority to vote on the shareholder’s proposal if it is properly brought before the meeting. If a shareholder makes a timely notification, the proxies may still exercise discretionary voting authority under circumstances consistent with the applicable proxy rules. All proposals by shareholders of the Fund that are intended to be presented at the Fund’s next annual meeting of shareholders to be held in 2018 must be received by the Fund for inclusion in the Fund’s proxy statement and proxy relating to that meeting no later than June 1, 2018.February 10, 2019. The submission by a shareholder of a proposal for inclusion in the proxy materials does not guarantee that it will be included. Shareholder proposals are subject to

12

certain requirements under the federal securities laws. Shareholder proposals should be addressed to the attention of the Secretary of the Fund at the address of the principal executive offices of the Fund.

A shareholder who wishes to send any other communications to the Board should also deliver such communications to the Secretary of the Fund at the address of the principal executive offices of the Fund. The Secretary is responsible for determining, in consultation with other officers of the Fund, counsel, and other advisers as appropriate, which shareholder communications will be relayed to the Board.

Other Matters

Neither the Board of Trustees nor management know of any matters to be presented at the Annual Meeting other than those mentioned in this Proxy Statement. If any other business should come before the meeting, the proxies will vote thereon in accordance with their best judgment.

By Order of the Trustees,

Clifford D. Corso, President

DatedSeptember 29, 2017May 30, 2018

IF YOU CANNOT ATTEND THE ANNUALSPECIAL MEETING, IT IS REQUESTED THAT YOU COMPLETE AND SIGN THE ENCLOSED PROXY CARD AND RETURN IT IN THE ENVELOPE PROVIDED SO THAT THE SPECIAL MEETING MAY BE HELD AND ACTION TAKEN ON THE MATTERS DESCRIBED HEREIN WITH THE GREATEST POSSIBLE NUMBER OF SHARES PARTICIPATING.

1311

EXHIBIT A

INSIGHT SELECT INCOME FUND

MANAGED DURATION INVESTMENT GRADE MUNICIPAL FUND

AUDIT COMMITTEE CHARTERFORM OF PLAN OF LIQUIDATION AND DISSOLUTION

II.    STATEMENT OF POLICY

The primary functionThis Plan of the Audit CommitteeLiquidation and Dissolution (the “Committee”“Plan”) of Insight Select Income Fund and Managed Duration Investment Grade Municipal Fund (the “Funds”“Fund”) is oversight. It is management’s responsibility to maintain appropriate systems for accountingeffective as of [                ], 2018 (the “Effective Date”), organized and internal control,existing as a Delaware statutory trust and the independent accountants’ responsibility to plan and carry outwhich has operated as a proper audit. The functions of the Committee are the sole responsibility of the Committee and may not be allocated to a different committee.

The Committee shall direct the retention of independent accountants and approve in advance all audit andnon-auditclosed-end services of the independent accountants. The Committee shall also review the Funds’ financial reporting process, the system of internal control, its audit process, and its processes, for monitoring compliance withmanagement investment restrictions and applicable laws and regulations and with the code of ethics. In performing its duties, the Committee shall maintain effective working relationships with the Board of Trustees, management, the internal auditor and the independent accountants. The Funds will not hire any personnel from independent accountants who have worked in any capacity on the Funds’ audit during the past three (3) years.

III.    ORGANIZATION

The Committee shall be comprised of at least three members, none of whom is an “interested person” of the Funds, as that term is defined incompany registered under the Investment Company Act of 1940. The Committee shall designate a Chairman by majority vote1940, as amended (the “1940 Act”), is intended to accomplish the complete liquidation and dissolution of the Committee.

ManagementFund in conformity with the laws of the Funds shall provide or arrangeState of Delaware.

WHEREAS, on May 10, 2018, the Fund’s Board of Trustees (the “Board”) unanimously determined that it is advisable to provide such information, dataliquidate and servicesdissolve the Fund; and

WHEREAS, the Board has considered and approved this Plan as the Committee may request. The Committee shall consult as it deems appropriate with personnelmethod of liquidating and service contractorsdissolving the Fund and has directed that the dissolution of the Funds and may engage and directFund be submitted to the Funds to compensate independent counsel, independent accountants or other advisers to independently inquire or investigate matters falling within the scope of this Charter. The Committee shall meet at least once annually to determine the firm to be employed as the Funds’ independent accountants and the proposed terms of such engagement, to discuss and approve the scopeshareholders of the next year’s auditFund (“Shareholders”) for their consideration;

NOW, THEREFORE, the liquidation and dissolution of the financial statements, and to reviewFund shall be carried out in the results of the audit for the prior year. The Committee shall meet with the Funds’ independent accountants at least once annually outside the presence of the Funds’ management representatives.

IV.    PRINCIPAL DUTIES

The Committee shall:manner hereinafter set forth:

The Liquidating Distribution to Common Shareholders will include, if necessary, a dividend equal to the sum of (i) the amount, if any, required to avoid the imposition of tax under section 852 of the Internal Revenue Code of 1986, as amended (the “Code”) on investment company taxable income and net capital gain for each of the Fund’s (a) most recently completed taxable year, and (b) the subsequent taxable period ending on the Liquidation Date and (ii) the additional amount, if any, required to avoid the imposition of tax under section 4982 of the Code on ordinary income and capital gain net income. It is intended that any and all amounts of a Liquidating Distribution to Common Shareholders comprising such a dividend shall be characterized in a manner consistent with Revenue Ruling89-81,1989-1 C.B. 226.

EVERY SHAREHOLDER’S VOTE IS IMPORTANT

						VOTE BY MAIL Vote, sign and date this Proxy Card and return in the postage-paid envelope
						VOTE IN PERSON Attend Shareholder Meeting 899 Cassatt Road Berwyn, Pennsylvania on December 6, 2017July 12, 2018

Please detach at perforation before mailing.

PROXY SOLICITED BY THE BOARD OF TRUSTEES.

The undersigned hereby appoints Thomas Stabile and James DiChiaro, each of them proxies, with full powers of substitution and revocation, to attend the AnnualSpecial Meeting of Shareholders of Managed Duration Investment Grade Municipal Fund on December 6, 2017July 12, 2018 and any adjournments thereof and to vote all shares which the undersigned would be entitled to vote if personally present, upon the following matters, as set forth in the Notice of AnnualSpecial Meeting of Shareholders, and upon such other business as may properly come before the meeting or any adjournment thereof.

If more than one of said proxies or their respective substitutes shall be present and vote at said meeting or any adjournment thereof, a majority of them so present and voting (or if only one be present and voting, then that one) shall have and exercise all the powers hereby granted. The undersigned revokes any proxy or proxies heretofore given to vote such shares at said meeting or any adjournment thereof.

PLEASE MARK, SIGN, DATE ON THE REVERSE SIDE AND RETURN THIS PROXY PROMPTLY USING THE ENCLOSED ENVELOPE.

MDI_29253_092817_PrefMDI_29826_052518

EVERY SHAREHOLDER’S VOTE IS IMPORTANT

Important Notice Regarding the Availability of Proxy Materials for the

AnnualSpecial Shareholder Meeting to Be Held on December 6, 2017.July 12, 2018.

The Proxy Statement and Proxy Card for this meeting are available at:

https://www.insightinvestment.com/globalassets/documents/mzf-reports/mzf-annual-proxy-statement-2017mzf-annual-proxy-statement

Please detach at perforation before mailing.

IF INSTRUCTIONS ARE NOT GIVEN, THIS PROXY WILL BE TREATED AS GRANTING AUTHORITY TO VOTE IN FAVOR OF THE ELECTION OF ALL OF THE NOMINATED TRUSTEES AND ANY SUBSEQUENT PROPOSAL.

TO VOTE MARK BLOCKS BELOW IN BLUE OR BLACK INK AS SHOWN IN THIS EXAMPLE:   ☒

		Proposal		THE BOARD RECOMMENDS THAT YOU CAST YOUR VOTE “FOR” THE PROPOSAL AS DESCRIBED IN THE PROXY STATEMENT.

		Authorized Signatures — This section must be completed for your vote to be counted.— Sign and Date Below

608999900109999999999

xxxxxxxxxxxxxx		MDI 2925329826		M     xxxxxxxx		+

EVERY SHAREHOLDER’S VOTE IS IMPORTANT

EASY VOTING OPTIONS:      

						VOTE BY MAIL Vote, sign and date this Proxy Card and return in the postage-paid envelope
						VOTE IN PERSON Attend Shareholder Meeting 899 Cassatt Road Berwyn, Pennsylvania on December 6, 2017

Please detach at perforation before mailing.

PROXY SOLICITED BY THE BOARD OF TRUSTEES.

The undersigned hereby appoints Thomas Stabile and James DiChiaro, each of them proxies, with full powers of substitution and revocation, to attend the Annual Meeting of Shareholders of Managed Duration Investment Grade Municipal Fund on December 6, 2017 and any adjournments thereof and to vote all shares which the undersigned would be entitled to vote if personally present, upon the following matters, as set forth in the Notice of Annual Meeting of Shareholders, and upon such other business as may properly come before the meeting or any adjournment thereof.

If more than one of said proxies or their respective substitutes shall be present and vote at said meeting or any adjournment thereof, a majority of them so present and voting (or if only one be present and voting, then that one) shall have and exercise all the powers hereby granted. The undersigned revokes any proxy or proxies heretofore given to vote such shares at said meeting or any adjournment thereof.

PLEASE MARK, SIGN, DATE ON THE REVERSE SIDE AND RETURN THIS PROXY PROMPTLY USING THE ENCLOSED ENVELOPE.

MDI_29253_092817

EVERY SHAREHOLDER’S VOTE IS IMPORTANT

Important Notice Regarding the Availability of Proxy Materials for the

Annual Shareholder Meeting to Be Held on December 6, 2017.

The Proxy Statement and Proxy Card for this meeting are available at:

https://www.insightinvestment.com/globalassets/documents/mzf-reports/mzf-annual-proxy-statement-2017

Please detach at perforation before mailing.

IF INSTRUCTIONS ARE NOT GIVEN, THIS PROXY WILL BE TREATED AS GRANTING AUTHORITY TO VOTE IN FAVOR OF THE ELECTION OF ALL OF THE NOMINATED TRUSTEES AND ANY SUBSEQUENT PROPOSAL.

TO VOTE MARK BLOCKS BELOW IN BLUE OR BLACK INK AS SHOWN IN THIS EXAMPLE:  ☒

		Proposal		THE BOARD RECOMMENDS THAT YOU CAST YOUR VOTE “FOR” THE PROPOSAL AS DESCRIBED IN THE PROXY STATEMENT.

		Authorized Signatures — This section must be completed for your vote to be counted.— Sign and Date Below

608999900109999999999

xxxxxxxxxxxxxx		MDI 29253		M     xxxxxxxx		+