Filed Pursuant to Rule 497(c)
Registration Statement No. 333-218384

PROSPECTUS SUPPLEMENT August 18, 2017
(to Prospectus dated August 2, 2017)

2,550,502 Common Shares

RMR Real Estate Income Fund

Issuable Upon Exercise of Transferable Rights to Subscribe for
Common Shares

         RMR Real Estate Income Fund (the "Fund") is a diversified, closed-end management investment company.

         The Fund is issuing transferable rights ("Rights") to its Common Shareholders of record ("Record Date Shareholders") as of 5:00 p.m., Eastern time, on August 21, 2017 (the "Record Date"), entitling the holders of those Rights to subscribe for up to an aggregate of 2,550,502 of the Fund's Common Shares (the "Offer"). The Fund's common shares of beneficial interest are referred to herein as "Common Shares" and holders thereof are referred to as "Common Shareholders". Record Date Shareholders will receive one Right for each outstanding whole Common Share held on the Record Date. The Rights entitle their holders to purchase one new Common Share for every three Rights held (1 for 3). The Rights offering will remain open for 30 days, unless extended. Any Record Date Shareholder who is issued fewer than three Rights may subscribe for one full Common Share in the Offer. In addition, Record Date Shareholders who fully exercise their Rights (other than those Rights that cannot be exercised because they represent the right to acquire less than one Common Share) will be entitled to subscribe for additional Common Shares of the Fund that remain unsubscribed as a result of any unexercised Rights. This over-subscription privilege is subject to a number of limitations and subject to allotment.

         The subscription price per Common Share (the "Subscription Price") will be determined based upon a formula equal to 90% of the average of the last reported sales price of a Common Share on the NYSE American LLC ("NYSE American") on the date on which the Offer expires, as such date may be extended from time to time, and each of the four (4) preceding trading days (the "Formula Price"). If, however, the Formula Price is less than 70% of the net asset value ("NAV") per Common Share at the close of trading on the NYSE American on the Expiration Date (as defined below), then the Subscription Price will be 70% of the Fund's NAV per Common Share at the close of trading on the NYSE American on the Expiration Date. There will be a sales load on the Subscription Price; however, the sales load will be borne by the Fund's investment adviser, RMR Advisors LLC (the "Investment Adviser"), and not the Fund or any Common Shareholders. The Offer will expire at 5:00 p.m., Eastern time, on September 19, 2017, unless extended as described in this Prospectus Supplement (the "Expiration Date").

         Rights holders may not know the Subscription Price at the time of exercise and will be required initially to pay for both the Common Shares subscribed for pursuant to the primary subscription and, if eligible, any additional common shares subscribed for pursuant to the over-subscription privilege at the estimated Subscription Price of $18.64 per Common Share and, except in limited circumstances, will not be able to rescind their subscription.

         Exercising your Rights and investing in the Fund's Common Shares involves a high degree of risk. See "Risk Factors and Special Considerations" on page 53 of the accompanying Prospectus.

         Upon the completion of the Offer, Record Date Shareholders who do not fully exercise their Rights will own a smaller proportional interest in the Fund than they owned prior to the Offer. The completion of the Offer will result in immediate voting dilution for such Common Shareholders. Further, expenses associated with the offer paid by the Fund, if any, may reduce the NAV per Common Share of each Common Shareholder's Common Shares. In addition, if the Subscription Price is less than the NAV per Common Share as of the Expiration Date, the completion of the Offer will result in an immediate dilution of NAV per Common Share for all Common Shareholders (i.e., will cause the NAV per Common Share of the Fund to decrease) and may have the effect of reducing the market price of the Fund's Common Shares. It is anticipated that the existing Common Shareholders will experience immediate dilution even if they fully exercise their Rights.

(continued on inside front cover)

         Neither the Securities and Exchange Commission ("SEC") nor any state securities commission has approved or disapproved of these securities or determined if this Prospectus Supplement or the accompanying Prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

(notes on inside front cover)

UBS Investment Bank

(notes from cover page)

(1)

Assumes that all Rights are exercised at the estimated Subscription Price. All of the Rights may not be exercised.

(2)

Estimated on the basis of 90% of the average of the last reported sales price per Common Share at the close of trading on the NYSE American on August 17, 2017 and each of the four (4) preceding trading days. See "Terms of the Offer—Subscription Price".

(3)

In connection with the Offer, UBS Securities LLC, the dealer manager for the Offer ("UBS" or the "Dealer Manager") will receive a fee for its financial structuring and soliciting services equal to 3.75% of the aggregate Subscription Price per Common Share for each Common Share issued pursuant to the Offer. Based on the Estimated Subscription Price, this Dealer Manager fee would amount to $0.699 per Common Share and a total sales load of $1,782,801. The Dealer Manager will reallow a part of its fees to other broker-dealers that have assisted in soliciting the exercise of the Rights. The Dealer Manager fee will be borne by the Investment Adviser, and not by the Fund or its Common Shareholders. The Fund and its Investment Adviser have agreed to indemnify the Dealer Manager against certain liabilities under the Securities Act of 1933, as amended (the "Securities Act").

(4)

The Investment Adviser, and not the Fund or its Common Shareholders, will bear all expenses incurred in connection with the Offer. Offering expenses borne by the Investment Adviser (including the reimbursements described below) are estimated to be approximately $568,000 in the aggregate, or $0.06 per Common Share (assuming the Rights are fully exercised). Since the Investment Adviser is bearing such expenses, the Per Common Share and Total Proceeds to the Fund are not estimated to be reduced as a result of such offering expenses. The Investment Adviser, and not the Fund, has agreed to pay the Dealer Manager up to $100,000 as a partial reimbursement for its expenses incurred in connection with the Offer. The Investment Adviser, and not the Fund, will also pay expenses relating to the printing or other production, mailing and delivery expenses incurred in connection with materials related to the Offer, including all reasonable out-of-pocket fees and expenses, if any and not to exceed $100,000, incurred by the Dealer Manager, Selling Group Members (as defined in this Prospectus Supplement), Soliciting Dealers (as defined in this Prospectus Supplement) and other brokers, dealers and financial institutions in connection with their customary mailing and handling of materials related to the Offer to their customers.

(5)

Funds received by check prior to the final due date of the Offer will be deposited into a segregated account pending proration and distribution of Common Shares. The Subscription Agent (as defined in this Prospectus Supplement) may receive investment earnings on the funds deposited into such account.

(continued from cover page)

        Such dilution is not currently determinable because it is not known how many Common Shares will be subscribed for, what the NAV or market price of the Common Shares will be on the Expiration Date or what the Subscription Price will be. Any such dilution will disproportionately affect non-exercising Common Shareholders. If the Subscription Price is substantially less than the current NAV, this dilution could be substantial. However, assuming all of the Common Shares are sold at the estimated Subscription Price, the Fund's current NAV per Common Share would be reduced by approximately $1.65, or 6.5%. The distribution to Common Shareholders of transferable Rights, which themselves have intrinsic value, will afford non-participating Common Shareholders of record on the Record Date the potential of receiving cash payment upon the sale of the Rights, receipt of which may be viewed as partial compensation for any dilution of their interests that may occur as a result of the Offer. There can be no assurance that a market for the Rights will develop or, if such a market develops, what the price of the Rights will be. Additionally, the fact that the Investment Adviser, and not the Fund, is paying the Dealer Manager fee and all other offering expenses (which include, among other items, reimbursement of Dealer Manager expenses, the expenses of preparing, printing and mailing the prospectus and Rights subscription materials for the Offer (including reimbursement of expenses of the Dealer Manager, Selling Group Members, Soliciting Dealers and other brokers, dealers and financial institutions), SEC registration fees and the fees assessed by service providers (including the cost of the Fund's counsel and independent registered public accounting firm)) may reduce the effects of dilution as a result of the Offer since the Fund's net assets will not additionally be reduced by the expenses of conducting the Offer and since the Fund will receive as proceeds from the Offer the full Subscription Price for each Common Share issued. See "Terms of the Offer—Investment Considerations and Dilution" in this Prospectus Supplement. Except as described herein, Rights holders will have no right to rescind their subscriptions after receipt of their payment for Common Shares by the Subscription Agent for the Offer.

        There is a risk that changes in market conditions may result in the underlying Common Shares purchasable upon exercise of the Rights being less attractive to investors at the Expiration Date. This may reduce or eliminate the value of the Rights. Investors who receive Rights may find that there is no market to sell Rights they do not wish to exercise. If investors exercise only a portion of the Rights, the number of Common Shares issued may be reduced, and the Common Shares may trade at less favorable prices than larger offerings for similar securities.

        Investment Objective.    The Fund's primary investment objective is to earn and pay to its Common Shareholders a high level of current income by investing in real estate companies. Capital appreciation is the Fund's secondary objective. The Fund is not intended as, and you should not construe it to be, a complete investment program. There can be no assurance that the Fund's investment objective will be achieved or that the Fund's investment program will be successful. The Fund's investment objectives are fundamental policies that cannot be changed without shareholder approval.

        Principal Investment Policies.    Under normal market conditions, the Fund invests at least 90% of its Managed Assets in income producing securities issued by real estate companies, including common shares, preferred shares and debt; at least 75% of its Managed Assets in securities issued by REITs; and no more than 10% of its Managed Assets in securities denominated in currencies other than the U.S. dollar or traded on a non-U.S. stock exchange. Additionally, the Fund will invest, under normal market conditions, at least 80% of its Managed Assets in securities issued by real estate companies. "Managed Assets" means the net asset value of the Fund's Common Shares plus the liquidation preference of the Fund's preferred shares and the principal amount of the Fund's outstanding borrowings.

        For the purposes of its investment policies, the Fund defines a "real estate company" as an entity that derives at least 50% of its revenues from the ownership, leasing, management, construction, sale or

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financing of commercial, industrial or residential real estate, or has at least 50% of its assets in real estate.

        REITs are financial vehicles that pool investors' capital to purchase or finance real estate. REITs are typically publicly traded corporations or trusts that invest in residential or commercial real estate, but may also be privately offered and/or not traded on any established market. REITs may concentrate their investments in specific geographic areas or in specific property types (i.e. hotels, shopping malls, residential complexes and office buildings). REITs generally can be divided into the following three types: (i) equity REITs which invest primarily in direct fee ownership or leasehold ownership of real property and derive their income primarily from rents and capital gains or real estate appreciation; (ii) mortgage REITs which invest mostly in real estate mortgage loans, which may secure construction, development or long-term loans, and derive their income primarily from interest payments; and (iii) hybrid REITs which combine the characteristics of equity REITs and mortgage REITs. REITs are subject to numerous organizational and operational requirements, including a requirement that they distribute each year at least 90% of their REIT taxable income, determined without regard to the deduction for dividends paid and excluding any net capital gains. REITs therefore offer attractive current income because they pay out substantially all of their taxable income as dividends. The Fund invests in common and preferred securities issued by REITs.

        Listing and Symbol.    The Fund's currently outstanding Common Shares are listed on the NYSE American under the symbol "RIF". As of August 17, 2017, the last reported sale price for the Fund's Common Shares on the NYSE American was $19.72 per Common Share. The NAV of the Fund's Common Shares as of the close of business on August 17, 2017, was $25.23 per Common Share. The Rights for Common Shares offered by this Prospectus Supplement and the accompanying Prospectus will be admitted for trading on the NYSE American under the symbol "RIF RT".

        This Prospectus Supplement, together with the accompanying Prospectus, dated August 2, 2017 (the "Prospectus"), sets forth concisely the information that you should know before investing in the Fund's Common Shares. You should read this Prospectus Supplement and the accompanying Prospectus, which contain important information about the Fund, before deciding whether to invest, and retain it for future reference. A Statement of Additional Information, dated August 2, 2017 (the "SAI"), as supplemented from time to time, containing additional information about the Fund, has been filed with the SEC and is incorporated by reference in its entirety into the accompanying Prospectus. This Prospectus Supplement describes the specific details regarding this offering, including the method of distribution. If information in this Prospectus Supplement is inconsistent with the accompanying Prospectus or the SAI, you should rely on this Prospectus Supplement. You may request a free copy of the SAI, the table of contents of which is on page 123 of the Prospectus, or request other information about the Fund (including the Fund's annual and semi-annual reports) or make shareholder inquiries by calling (617) 332-9530 or by writing to the Investment Adviser at RMR Advisors LLC, Two Newton Place, 255 Washington Street, Suite 300, Newton, Massachusetts 02458, or you may obtain a copy (and other information regarding the Fund) from the SEC's web site (http://www.sec.gov). Free copies of the Fund's reports will also be available from the Fund's web site at www.rmrfunds.com.

        The Fund's Common Shares 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.

        Capitalized terms used herein that are not otherwise defined shall have the meanings assigned to them in the accompanying Prospectus.

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TABLE OF CONTENTS

        You should rely only on the information contained or incorporated by reference in this Prospectus Supplement. The Fund has not, and the Dealer Manager 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, and the Dealer Manager is not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted.

FORWARD-LOOKING STATEMENTS

        This Prospectus Supplement contains or incorporates by reference forward-looking statements, within the meaning of U.S. federal securities laws, that involve risks and uncertainties. These statements describe the Fund's plans, strategies, and goals and our beliefs and assumptions concerning future economic and other conditions and the outlook for the Fund, based on currently available information. In this Prospectus Supplement, words such as "anticipates", "believes", "expects", "objectives", "goals", "future", "intends", "seeks", "will", "may", "could", "should", and similar expressions are used in an effort to identify forward-looking statements, although some forward-looking statements may be expressed differently. The Fund is not entitled to the safe harbor for forward-looking statements pursuant to Section 27A of the Securities Act of 1933, as amended.

PROSPECTUS SUPPLEMENT SUMMARY

        This is only a summary of information contained elsewhere in this Prospectus Supplement and the accompanying Prospectus. This summary does not contain all of the information that you should consider before investing in the Fund's Common Shares. You should carefully read the more detailed information contained in this Prospectus Supplement and the accompanying Prospectus and the SAI, especially the information set forth under the headings "Investment Objective and Policies" and "Risk Factors and Special Considerations". Capitalized terms used herein that are not otherwise defined shall have the meanings assigned to them in the accompanying Prospectus.

        The Fund    RMR Real Estate Income Fund is a diversified, closed-end management investment company registered under the Investment Company Act of 1940 and organized as a Maryland statutory trust.

        Purpose of the Offer    The Board of Trustees of the Fund (the "Board"), based on the recommendations of and presentations by the Fund's Investment Adviser, RMR Advisors LLC, and others, has determined that it is in the best interests of the Fund and its Common Shareholders to conduct the Offer and thereby to increase the assets of the Fund available for investment. In making this determination, the Board considered a number of factors, including potential benefits and costs. In particular, the Board considered the Investment Adviser's belief that the Offer would better enable the Fund to take advantage more fully of existing and future investment opportunities that may be or may become available, consistent with the Fund's primary investment objective to earn and pay to its Common Shareholders a high level of current income. By increasing assets through the Offer, the Fund believes that it will be able to invest in additional securities of real estate investment trusts ("REITs") offering attractive current income, competitive total returns and meaningful portfolio diversification.

        The Offer seeks to provide an opportunity to existing Common Shareholders to purchase Common Shares at a discount to market price. The distribution to Common Shareholders of transferable Rights, which may themselves have intrinsic value, also will afford non-participating Common Shareholders of record on the Record Date the potential of receiving cash payment upon the sale of the Rights, receipt of which may be viewed as partial compensation for any dilution of their interests that may occur as a result of the Offer. There can be no assurance that a market for the Rights will develop or, if such a market does develop, what the price of the Rights will be.

        In making its determination that the Offer is in the best interests of the Fund and its Common Shareholders, the Board considered (in addition to the Investment Adviser's belief as to the potential investment opportunities) various factors, including: (i) the size, pricing and structure of the Offer; (ii) that the Offer, if it is well-subscribed, could increase the liquidity of the Common Shares on the NYSE American, where the Common Shares are traded; (iii) the opportunity the Offer represents for current Common Shareholders to buy Common Shares at a discount to net asset value or market price, or, in some cases, both; (iv) the consequences of the Offer, including dilution of Common Shareholders' interests through the Offer; (v) the possible negative effect on the market price of Common Shares the Offer may have; and (vi) that the Offer will increase the Fund's asset base and thus allow it to spread fixed expenses over a larger base of assets, which may decrease the Fund's expense ratio. The Board noted that the Investment Adviser has an inherent conflict of interest in recommending the Offer because its fees are based on a percentage of the Fund's average daily Managed Assets (the greater the Managed Assets of the Fund, the greater the compensation paid to the Investment Adviser).

        There can be no assurance that the Offer (or the investment of the proceeds of the Offer) will be successful. For a discussion of the potential impact of the Offer on current Common Shareholders, such as dilution, see "Risks Related to the Offer" in this Prospectus Supplement.

S-1

        Important Terms of the Offer    The Fund is issuing transferable Rights to its Record Date Shareholders as of 5:00 p.m., Eastern time, on the Record Date of August 21, 2017, entitling the holders of those Rights to subscribe for up to an aggregate of 2,550,502 Common Shares. Record Date Shareholders will receive one Right for each outstanding whole Common Share held on the Record Date. The Rights entitle their holders to purchase one Common Share for every three Rights held (1 for 3). Fractional Common Shares will not be issued upon the exercise of Rights; accordingly, Rights may be exercised only in integer multiples of three, except that any Record Date Shareholder who is issued fewer than three Rights may subscribe, at the Subscription Price, for one full Common Share. Assuming the exercise of all Rights, the Offer will result in an approximately 33¹/3% increase in the Fund's Common Shares outstanding. The Offer is not contingent upon any number of Rights being exercised. The subscription period commences on August 21, 2017, and ends at 5:00 p.m., Eastern time, on the Expiration Date of September 19, 2017, unless otherwise extended. See "Terms of the Offer—Important Terms of the Offer".

        The Fund has declared a regular quarterly distribution to Common Shareholders payable on September 29, 2017, which will not be payable with respect to Common Shares issued pursuant to the Offer.

        The Investment Adviser, and not the Fund, will bear the expenses of the Offer; therefore, none of such expenses will be borne by the Fund's Common Shareholders. These expenses include, but are not limited to, the Dealer Manager fee, reimbursement of the Dealer Manager's expenses, the expenses of preparing, printing and mailing the prospectus and Rights subscription materials for the Offer (including reimbursement of expenses of the Dealer Manager, Selling Group Members, Soliciting Dealers and other brokers, dealers and financial institutions), SEC registration fees and the fees assessed by service providers (including the cost of the Fund's counsel and independent registered public accounting firm) in connection with the Offer. This commitment by the Investment Adviser may reduce the effects of dilution as a result of the Offer since the Fund's net assets will not additionally be reduced by the expenses of conducting the Offer and since the Fund will receive as proceeds from the Offer the full Subscription Price for each Common Share issued.

Important Dates to Remember

        Subscription Price    The Subscription Price per Common Share will be determined based on a formula equal to 90% of the average of the last reported sales price of a Common Share on the NYSE American on the date on which the Offer expires, as such date may be extended from time to time, and each of the four (4) preceding trading days (the "Formula Price", as defined in this Prospectus Supplement). If, however, the Formula Price is less than 70% of the NAV per Common Share at the close of trading on the NYSE American on the Expiration Date, then the Subscription Price will be 70% of the Fund's NAV per Common Share at the close of trading on the NYSE American on the Expiration Date. Because the Expiration Date of the subscription period will be September 19, 2017

S-2

(unless the subscription period is extended), Rights holders may not know the Subscription Price at the time of exercise and will be required initially to pay for both the Common Shares subscribed for pursuant to the primary subscription and, if eligible, any additional Common Shares subscribed for pursuant to the over-subscription privilege, at the estimated Subscription Price of $18.64 per Common Share and, except in limited circumstances, will not be able to rescind their subscription. The Investment Adviser, and not the Fund or Common Shareholders, will pay a sales load on the Subscription Price. See "Terms of the Offer—Subscription Price".

        Oversubscription Privilege    Record Date Shareholders who fully exercise all the Rights issued to them (other than those Rights that cannot be exercised because they represent the right to acquire less than one Common Share) are entitled to subscribe for additional Common Shares at the same Subscription Price pursuant to the over-subscription privilege (the "Over-Subscription Privilege"), subject to certain limitations and subject to allotment. Investors who are not Record Date Shareholders, but who otherwise acquire Rights pursuant to the Offer, are not entitled to subscribe for any Common Shares pursuant to the Over-Subscription Privilege. If sufficient remaining Common Shares are available following the primary subscription, all Record Date Shareholders' over-subscription requests will be honored in full. If sufficient Common Shares are not available to honor all over-subscription requests, unsubscribed Common Shares will be allocated pro rata among those Record Date Shareholders who over-subscribe based on the number of Common Shares they owned on the Record Date. See "Terms of the Offer—Over-Subscription Privilege".

        Sale and Transferability of Rights    The Rights will be admitted for trading on the NYSE American under the symbol "RIF RT" during the course of the Offer. It is expected that trading in the Rights on the NYSE American may be conducted until the close of trading on the NYSE American on the last business day prior to the Expiration Date of the Offer. The Fund will use its best efforts to ensure that an adequate trading market for the Rights will exist, although there can be no assurance that a market for the Rights will develop. Assuming a market exists for the Rights, the Rights may be purchased and sold through usual brokerage channels or sold through the Subscription Agent.

        Record Date Shareholders who do not wish to exercise any or all of the Rights issued to them pursuant to the Offer may instruct the Subscription Agent to try to sell any unexercised Rights through or to the Dealer Manager. Subscription certificates representing the Rights to be sold through or to the Dealer Manager must be received by the Subscription Agent by 5:00 p.m., Eastern time, on September 12, 2017 (or, if the subscription period is extended, by 5:00 p.m., Eastern time, on the fifth business day prior to the extended Expiration Date).

        Alternatively, the Rights evidenced by a subscription certificate may be transferred until the Expiration Date in whole or in part by endorsing the subscription certificate for transfer in accordance with the accompanying instructions. A portion of the Rights evidenced by a single subscription certificate (but not fractional Rights) may be transferred by delivering to the Subscription Agent a subscription certificate properly endorsed for transfer, with instructions to register such portion of the Rights evidenced thereby in the name of the transferee and to issue a new subscription certificate to the transferee evidencing the transferred Rights. See "Terms of the Offer—Sale and Transferability of Rights".

        Method for Exercising Rights    Rights are evidenced by subscription certificates that will be mailed to Record Date Shareholders (except as described below under "Terms of the Offer—Requirements for Foreign Shareholders") or, if their Common Shares are held by Cede & Co. or any other depository or nominee, to Cede & Co. or such other depository or nominee. Rights may be exercised by completing and signing the subscription certificate and mailing it in the envelope provided, or otherwise delivering the completed and signed subscription certificate to the Subscription Agent, together with payment in full of the estimated Subscription Price for the Common Shares subscribed for. Completed subscription certificates and payments must be received by the Subscription Agent by 5:00 p.m., Eastern time, on

S-3

the Expiration Date at the offices of the Subscription Agent. Rights also may be exercised by contacting your broker, bank, trust company or other intermediary, which can arrange, on your behalf, to guarantee delivery of payment and of a properly completed and executed subscription certificate. A fee may be charged for this service by your broker, banker, trust company or other intermediary. In addition, your broker, bank, trust company or other intermediary may impose a deadline for exercising Rights earlier than 5:00 p.m., Eastern time, on the Expiration Date. See "Terms of the Offer—Method for Exercising Rights" and "Terms of the Offer—Payment for Shares".

        Rights holders who have exercised their Rights will have no right to rescind their subscription after receipt by the Subscription Agent of the completed subscription certificate together with payment for Common Shares subscribed for, except as described under "Terms of the Offer—Notice of Net Asset Value Decline".

        Requirements for Foreign Shareholders    Subscription certificates will not be mailed to Record Date Shareholders whose addresses are outside the United States (for these purposes, the United States includes the District of Columbia and the territories and possessions of the United States) (the "Foreign Shareholders"). The Subscription Agent will send a letter via regular mail to Foreign Shareholders to notify them of the Offer. The Rights of Foreign Shareholders will be held by the Subscription Agent for their accounts until instructions are received to exercise the Rights. If instructions have not been received by 5:00 p.m., Eastern time, on September 12, 2017, five (5) business days prior to the Expiration Date (or, if the subscription period is extended, on or before the fifth business day prior to the extended Expiration Date), the Rights of Foreign Shareholders will be transferred by the Subscription Agent to the Dealer Manager, who will either purchase the Rights or use its best efforts to sell the Rights. If the Dealer Manager declines to purchase the Rights, the Subscription Agent will attempt to sell such Rights in the open market. The net proceeds, if any, from the sale of those Rights by or to the Dealer Manager will be remitted to these Foreign Shareholders.

        U.S. Federal Income Tax Consequences to Common Shareholders    For U.S. federal income tax purposes, the receipt of Rights by a Record Date Shareholder should not be a taxable event. We urge you to consult your own tax adviser with respect to the particular tax consequences of the Offer. See "U.S. Federal Income Tax Consequences" for more information on the tax consequences of the Offer.

        Distribution Arrangements    UBS Securities LLC will act as Dealer Manager for this Offer. Under the terms and subject to the conditions contained in the Dealer Manager Agreement among the Dealer Manager, the Fund and the Investment Adviser, the Dealer Manager will provide financial structuring and solicitation services in connection with the Offer and will solicit the exercise of Rights and participation in the Over-Subscription Privilege. The Offer is not contingent upon any number of Rights being exercised. The Investment Adviser, and not the Fund, has agreed to pay the Dealer Manager a fee for its financial structuring and soliciting services equal to 3.75% of the aggregate Subscription Price for the Common Shares issued pursuant to the exercise of Rights and the Over-Subscription Privilege. The Investment Adviser, and not the Fund, has also agreed to pay the Dealer Manager up to $100,000 as a partial reimbursement for its reasonable out-of-pocket expenses incurred in connection with the Offer. The Investment Adviser, and not the Fund, will also pay expenses relating to the printing or other production, mailing and delivery expenses incurred in connection with materials related to the Offer, including all reasonable out-of-pocket fees and expenses, if any and not to exceed $100,000, incurred by the Dealer Manager, Selling Group Members, Soliciting Dealers and other brokers, dealers and financial institutions in connection with their customary mailing and handling of materials related to the Offer to their customers. The fees paid to the Dealer Manager and other expenses of the Offer will be borne by the Investment Adviser, and not the Fund, and therefore will not be borne by the Fund's Common Shareholders. The Dealer Manager will reallow a portion of its fees to other broker-dealers who have assisted in soliciting the exercise of the Rights. The Fund and the Investment Adviser have each agreed to indemnify the Dealer Manager for losses arising out of certain liabilities, including liabilities under the Securities Act.

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        Prior to the expiration of the Offer, the Dealer Manager may independently offer for sale Common Shares it has acquired through purchasing and exercising the Rights, at prices it sets. Although the Dealer Manager may realize gains and losses in connection with purchases and sales of Common Shares, such offering of Common Shares is intended by the Dealer Manager to facilitate the Offer, and any such gains or losses are not expected to be material to the Dealer Manager. The Dealer Manager's fee for its financial structuring and soliciting services is independent of any gains or losses that may be realized by the Dealer Manager through the purchase and exercise of the Rights and the sale of Common Shares. See "Terms of the Offer—Distribution Arrangements".

        Management of the Fund    RMR Advisors LLC serves as the Fund's Investment Adviser and is responsible for the management of the Fund. RMR Advisors LLC acts as the Fund's Investment Adviser pursuant to an advisory agreement with the Fund. The Investment Adviser is a registered investment adviser headquartered in Newton, Massachusetts.

        Benefits to the Investment Adviser    The Investment Adviser will benefit from the Offer, in part, because the investment management fee paid by the Fund to the Investment Adviser is based on the "Managed Assets" of the Fund. It is not possible to state precisely the amount of additional compensation the Investment Adviser will receive as a result of the Offer because it is not known how many Common Shares will be subscribed for and because the proceeds of the Offer will be invested in additional portfolio securities which will fluctuate in value. However, assuming (i) all Rights are exercised, (ii) the Fund's average daily net asset value during the twelve-month period beginning October 1, 2017 is $25.23 per Common Share (the NAV per Common Share on August 17, 2017), (iii) the Subscription Price is $18.64 per Common Share, and (iv) for purposes of this example, the Fund increases the amount of leverage it has outstanding while maintaining approximately the same percentage of total assets attributable to leverage, the Investment Adviser would receive additional investment management fees of approximately $565,602, for the twelve-month period beginning October 1, 2017, and would continue to receive additional investment management fees, as a result of the Offer, based on the Fund's Managed Assets attributable to the Common Shares issued in the Offer and related additional leverage, thereafter.

        Listing and Symbol    The Fund's currently outstanding Common Shares are listed on the NYSE American under the symbol "RIF". As of August 17, 2017, the last reported sale price for the Fund's Common Shares was $19.72. The NAV per share of the Fund's Common Shares at the close of business on August 17, 2017, was $25.23. The Rights offered by this Prospectus Supplement and the accompanying Prospectus will be, subject to notice of issuance, admitted for trading on the NYSE American under the symbol "RIF RT".

        Risks    See "Risks Related to the Offer" beginning on page 30 of this Prospectus Supplement and "Risk Factors and Special Considerations" beginning on page 53 of the accompanying Prospectus for a discussion of factors you should consider carefully before deciding to invest in the Fund's Common Shares.

        Use of Proceeds    The Fund estimates the net proceeds of the Offer, assuming all Common Shares offered hereby are sold, to be approximately $47,541,357. This figure is based on the estimated Subscription Price per Common Share of $18.64 and assumes all new Common Shares offered are sold and that the Dealer Manager fee and other expenses related to the Offer, such other expenses being estimated at approximately $568,000, are borne by the Investment Adviser.

        The Fund intends to invest the net proceeds of the Offer in accordance with its investment objective and policies as stated in the accompanying Prospectus. It is currently anticipated that the Fund will be able to invest substantially all of the net proceeds of the Offer in accordance with its investment objective and policies within three months after the completion of the Offer; however, changes in market conditions could result in the Fund's anticipated investment period extending to as

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long as six months. Pending such investment, it is anticipated that the proceeds will be invested in cash, cash equivalents or other securities, including U.S. government securities or high quality, short-term debt securities. The Fund may also use the proceeds for working capital purposes, including the payment of distributions, interest and operating expenses, although the Fund currently has no intent to use the proceeds primarily for these purposes.

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SUMMARY OF FUND EXPENSES

        The following table contains information about the costs and expenses that Common Shareholders will bear, directly or indirectly, as a result of the Offer. The table is based on the capital structure of the Fund as of June 30, 2017 (except as noted below) after giving effect to the Offer, assuming that the Offer is fully subscribed resulting in the receipt of net proceeds from the Offer of $47,541,357. If the Fund issues fewer Common Shares in the Offer and the net proceeds to the Fund are less, all other things being equal, the total annual expenses shown would increase. The purpose of the table and the example below is to help you understand the fees and expenses that you, as a holder of Common Shares, would bear directly or indirectly.

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Example

        As required by relevant SEC regulations, the following Example illustrates the expenses that you would pay on a $1,000 investment in Common Shares, assuming (1) the Offer is fully subscribed, (2) "Total annual expenses and Dividends on Preferred Shares" of 2.66% of net assets attributable to Common Shares, (3) that the Fund will not pay any sales load or bear any of the estimated offering expenses, and (4) a 5% annual return*:

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FINANCIAL HIGHLIGHTS

        The selected data below sets forth the per Common Share operating performance and ratios for the periods presented. The financial information was derived from and should be read in conjunction with the Financial Statements of the Fund and Notes thereto, which are incorporated by reference into the Statement of Additional Information. The financial information for each of the fiscal years ended December 31, 2016, 2015, 2014, 2013 and 2012 has been audited by Ernst & Young LLP, the Fund's independent registered public accounting firm, whose unqualified report on such Financial Statements is included in the Fund's annual report to shareholders, filed with the SEC on Form N-CSR on February 21, 2017, for the fiscal year ended December 31, 2016, and which is available without charge by calling the Fund's toll free number: (617) 332-9530. The financial information for the six months ended June 30, 2017 is unaudited.

        Selected data for a common share of beneficial interest outstanding throughout the period.

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CAPITALIZATION

        The following table sets forth the Fund's capitalization at June 30, 2017:

(i)

on a historical basis; and



(ii)

on an as adjusted basis to reflect the assumed sale of 2,550,502 Common Shares at a price of $18.64 per Common Share in the Offer under this Prospectus Supplement and the accompanying Prospectus, that the Fund will not pay any Dealer Manager fee or bear any offering expenses, and the application of the estimated net proceeds from the Offer. This table assumes that all Rights are exercised at the estimated Subscription Price. All of the Rights may not be exercised.

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USE OF PROCEEDS

        The Fund estimates the net proceeds of the Offer to be approximately $47,541,357. This figure is based on the Subscription Price per Common Share of $18.64 and assumes all Common Shares offered are sold and that the Dealer Manager fee and other expenses related to the Offer, such other expenses being estimated at approximately $568,000, are borne by the Investment Adviser.

        The Fund intends to invest the net proceeds of the Offer in accordance with its investment objective and policies as stated in the accompanying Prospectus. It is currently anticipated that the Fund will be able to invest substantially all of the net proceeds of the Offer in accordance with its investment objective and policies within three months after the completion of the Offer; however, changes in market conditions could result in the Fund's anticipated investment period extending to as long as six months. Pending such investment, it is anticipated that the proceeds will be invested in cash, cash equivalents or other securities, including U.S. government securities or high quality, short-term debt securities. The Fund may also use the proceeds for working capital purposes, including the payment of distributions, interest and operating expenses, although the Fund currently has no intent to use the proceeds primarily for these purposes.

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PRICE RANGE OF COMMON SHARES

        The following table sets forth, for the quarters indicated, the high and low sale prices on the NYSE American per share of our Common Shares and the net asset value and the premium or discount from net asset value per share at which the Common Shares were trading, expressed as a percentage of net asset value, at each of the high and low sale prices provided.

        The last reported price for our Common Shares on August 17, 2017 was $19.72 per share. As of August 17, 2017 the net asset value per share of the Fund's Common Shares was $25.23.

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TERMS OF THE OFFER

Purpose of the Offer

        The Board, based on the recommendations of and presentations by the Fund's Investment Adviser, and others, has determined that it is in the best interests of the Fund and its Common Shareholders to conduct the Offer and thereby to increase the assets of the Fund available for investment. In making this determination, the Board considered a number of factors, including potential benefits and costs. In particular, the Board considered the Investment Adviser's belief that the Offer would better enable the Fund to take advantage more fully of existing and future investment opportunities that may be or may become available, consistent with the Fund's primary investment objective to earn and pay to its Common Shareholders a high level of current income. By increasing assets through the Offer, the Fund believes that it will be able to invest in additional securities of real estate investment trusts ("REITs") offering attractive current income, competitive total returns and meaningful portfolio diversification.

        The Offer seeks to provide an opportunity to existing Common Shareholders to purchase Common Shares at a discount to market price. The distribution to Common Shareholders of transferable Rights, which may themselves have intrinsic value, also will afford non-participating Common Shareholders of record on the Record Date the potential of receiving cash payment upon the sale of the Rights, receipt of which may be viewed as partial compensation for any dilution of their interests that may occur as a result of the Offer. There can be no assurance that a market for the Rights will develop or, if such a market does develop, what the price of the Rights will be.

        In making its determination that the Offer is in the best interests of the Fund and its Common Shareholders, the Board considered (in addition to the Investment Adviser's belief as to the potential investment opportunities) various factors, including: (i) the size, pricing and structure of the Offer; (ii) that the Offer, if it is well-subscribed, could increase the liquidity of the Common Shares on the NYSE American, where the Common Shares are traded; (iii) the opportunity the Offer represents for current Common Shareholders to buy Common Shares at a discount to net asset value or market price, or, in some cases, both; (iv) the consequences of the Offer, including dilution of Common Shareholders' interests through the Offer; (v) the possible negative effect on the market price of Common Shares the Offer may have; and (vi) that the Offer will increase the Fund's asset base and thus allow it to spread fixed expenses over a larger base of assets, which may decrease the Fund's expense ratio. The Board noted that the Investment Adviser has an inherent conflict of interest in recommending the Offer because its fees are based on a percentage of the Fund's average daily Managed Assets (the greater the Managed Assets of the Fund, the greater the compensation paid to the Investment Adviser).

        There can be no assurance that the Offer (or the investment of the proceeds of the Offer) will be successful. For a discussion of the potential impact of the Offer on current Common Shareholders, such as dilution, see "Risks Related to the Offer" in this Prospectus Supplement.

Important Terms of the Offer

        The Fund is issuing Rights to its Record Date Shareholders as of 5:00 p.m., Eastern time, on the Record Date of August 21, 2017, entitling the holders of those Rights to subscribe for up to an aggregate of 2,550,502 of the Fund's Common Shares. Record Date Shareholders will receive one Right for each outstanding whole Common Share held on the Record Date. The Rights entitle their holders to purchase one Common Share for every three Rights held (1 for 3). Fractional Shares will not be issued upon the exercise of Rights; accordingly, Rights may be exercised only in integer multiples of three, except that any Record Date Shareholder who is issued fewer than three Rights may subscribe, at the Subscription Price, for one full Common Share. Assuming the exercise of all Rights, the Offer will result in an approximately 33¹/3% increase in the Fund's Common Shares outstanding.

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        Record Date Shareholders who fully exercise all the Rights issued to them (other than those Rights that cannot be exercised because they represent the right to acquire less than one Common Share) are entitled to subscribe for additional Common Shares at the same Subscription Price pursuant to the Over-Subscription Privilege, subject to certain limitations and subject to allotment. Investors who are not Record Date Shareholders, but who otherwise acquire Rights pursuant to the Offer, are not entitled to subscribe for any Common Shares pursuant to the Over-Subscription Privilege. See "—Over-Subscription Privilege". The distribution to Record Date Shareholders of transferable Rights may afford non-participating Record Date Shareholders the opportunity to sell their Rights for some cash value, receipt of which may be viewed as partial compensation for any economic dilution of their interests resulting from the Offer.

        The subscription period commences on August 21, 2017, and ends at 5:00 p.m., Eastern time, on the Expiration Date of September 19, 2017, unless otherwise extended.

        The Fund has declared a regular quarterly distribution to Common Shareholders payable on September 29, 2017, which will not be payable with respect to Common Shares issued pursuant to the Offer.

        For purposes of determining the maximum number of Common Shares a Rights holder may acquire pursuant to the Offer, broker-dealers, trust companies, banks or others whose Common Shares are held of record by Cede & Co., the nominee for the Depository Trust Company ("DTC"), or by any other depository or nominee, will be deemed to be the holders of the Rights that are held by Cede & Co. or such other depository or nominee on their behalf.

        The Rights are transferable and will be admitted for trading on the NYSE American under the symbol "RIF RT" during the course of the Offer. It is expected that trading in the Rights on the NYSE American may be conducted until the close of trading on the NYSE American on the last business day prior to the Expiration Date. See "—Sale and Transferability of Rights". The Common Shares, once issued, will be listed on the NYSE American under the symbol "RIF". The Rights will be evidenced by subscription certificates which will be mailed to Record Date Shareholders, except as discussed under "—Requirements for Foreign Shareholders".

        Rights may be exercised by filling in and signing the subscription certificate and mailing it in the envelope provided, or otherwise delivering the completed and signed subscription certificate to Computershare Inc. which, together with Computershare Trust Company, N.A., serves as the subscription agent for the Offer (the "Subscription Agent"), together with payment at the estimated Subscription Price for the Common Shares subscribed for. For a discussion of the method by which Rights may be exercised and Common Shares may be paid for, see "—Method for Exercising Rights" and "—Payment for Shares".

        The Fund has retained UBS, the Dealer Manager, to provide the Fund with financial structuring and soliciting services relating to the Offer, including advice with respect to the structure, timing and terms of the Offer. In determining the structure of the Offer, the Board considered, among other things, using a fixed-pricing versus a variable-pricing mechanism, the benefits and drawbacks of conducting a non-transferable versus a transferable rights offering, the anticipated effect on the Fund and its existing Common Shareholders if the Offer is not fully subscribed, the anticipated dilutive effects on the Fund and its existing Common Shareholders of the Offer and the experience of the Dealer Manager in conducting rights offerings. The Board also considered that the Investment Adviser would benefit from the Offer because the investment management fee paid to the Investment Adviser is based on the Fund's total Managed Assets, which would increase as a result of the Offer. See "—Benefits to the Investment Adviser". The Board further considered that the Investment Adviser has agreed to pay the Dealer Manager fee and all other offering expenses, which could have the effect of reducing the dilution to NAV from the Offer. See "—Expenses of the Offer", "—Compensation to Dealer Manager" and "—Investment Considerations and Dilution".

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Important Dates to Remember

Subscription Price

        The Subscription Price per Common Share will be determined based on the Formula Price, a formula equal to 90% of the average of the last reported sales price of a Common Share on the NYSE American on the date on which the Offer expires, as such date may be extended from time to time, and each of the four (4) preceding trading days. If, however, the Formula Price is less than 70% of the NAV per Common Share at the close of trading on the NYSE American on the Expiration Date, then the Subscription Price will be 70% of the Fund's NAV per Common Share at the close of trading on the NYSE American on the Expiration Date. In each case, NAV will be calculated as of the close of trading on the NYSE American on the applicable day. The Investment Adviser, and not the Fund, will pay a sales load on the Subscription Price.

        Because the Expiration Date of the subscription period will be September 19, 2017 (unless the subscription period is extended), Rights holders may not know the Subscription Price at the time of exercise and will be required initially to pay for both the Common Shares subscribed for pursuant to the primary subscription and, if eligible, any additional Common Shares subscribed for pursuant to the Over-Subscription Privilege, at the estimated Subscription Price of $18.64 per Common Share. See "—Payment for Shares". A Rights holder will have no right to rescind his subscription after the Subscription Agent has received a completed subscription certificate together with payment for the Common Shares subscribed for, except as provided under "—Notice of Net Asset Value Decline". The Fund does not have the right to withdraw the Rights or to cancel the Offer after the Rights have been distributed.

        The NAV per Common Share at the close of business on August 17, 2017 was $25.23, and the last reported sale price of a Common Share on the NYSE American on that day was $19.72.

Over-Subscription Privilege

        Record Date Shareholders who fully exercise all the Rights issued to them (other than those Rights that cannot be exercised because they represent the right to acquire less than one Common Share) are entitled to subscribe for additional Common Shares which were not subscribed for by other holders of Rights at the same Subscription Price pursuant to the Over-Subscription Privilege, subject to certain limitations and subject to allotment. Investors who are not Record Date Shareholders, but who otherwise acquire Rights pursuant to the Offer, are not entitled to subscribe for any Common Shares pursuant to the Over-Subscription Privilege. If sufficient remaining Common Shares are available following the primary subscription, all Record Date Shareholders' over-subscription requests will be honored in full. If sufficient Common Shares are not available to honor all over-subscription requests, unsubscribed Common Shares will be allocated pro rata among those Record Date Shareholders who

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over-subscribe based on the number of Common Shares of the Fund they owned on the Record Date. The allocation process may involve a series of allocations in order to ensure that the total number of Common Shares available for over-subscriptions is distributed on a pro rata basis.

        Record Date Shareholders who are fully exercising their Rights during the subscription period should indicate, on the subscription certificate that they submit with respect to the exercise of the Rights issued to them, how many Common Shares they desire to acquire pursuant to the Over-Subscription Privilege.

        Banks, broker-dealers, trustees and other nominee holders of Rights will be required to certify to the Subscription Agent, before any Over-Subscription Privilege may be exercised with respect to any particular beneficial owner, as to the aggregate number of Rights exercised during the subscription period and the number of Common Shares subscribed for pursuant to the Over-Subscription Privilege by such beneficial owner, and that such beneficial owner's primary subscription was exercised in full. Nominee holder over-subscription forms will be distributed to banks, brokers, trustees and other nominee holders of Rights with the subscription certificates.

        The Fund will not offer or sell any Common Shares that are not subscribed for during the subscription period or pursuant to the Over-Subscription Privilege.

        The Fund has been advised that one or more of the directors, trustees, officers or employees of the Fund and/or Investment Adviser may exercise all of the Rights initially issued to them and may request additional Common Shares pursuant to the Over-Subscription Privilege. An exercise of the Over-Subscription Privilege by such persons will increase their proportionate voting power and share of the Fund's assets.

Sale and Transferability of Rights

        The Rights will be admitted for trading on the NYSE American under the symbol "RIF RT" during the course of the Offer. It is expected that trading in the Rights on the NYSE American may be conducted until the close of trading on the Exchange on the last business day prior to the Expiration Date. The Fund will use its best efforts to ensure that an adequate trading market for the Rights will exist, although there can be no assurance that a market for the Rights will develop. Assuming a market exists for the Rights, the Rights may be purchased and sold through usual brokerage channels or sold through the Subscription Agent.

        Sales through the Subscription Agent and the Dealer Manager.    Record Date Shareholders who do not wish to exercise any or all of the Rights issued to them pursuant to the Offer may instruct the Subscription Agent to try to sell any unexercised Rights through or to the Dealer Manager. Subscription certificates representing the Rights to be sold through or to the Dealer Manager must be received by the Subscription Agent by 5:00 p.m., Eastern time, on September 12, 2017 (or, if the subscription period is extended, by 5:00 p.m., Eastern time, on the fifth business day prior to the extended Expiration Date). Upon the timely receipt by the Subscription Agent of appropriate instructions to sell Rights, the Subscription Agent will ask the Dealer Manager either to purchase them or to use its best efforts to complete their sale, and the Subscription Agent will remit the proceeds of the sale to the selling Rights holder. If the Rights are sold, sales of those Rights will be deemed to have been effected at the weighted average price received by the Dealer Manager on the day those Rights are sold. The sale price of any Rights sold to the Dealer Manager will be based upon the then-current market price for the Rights. The Dealer Manager will also attempt to sell all Rights that remain unclaimed as a result of subscription certificates being returned by the postal authorities to the Subscription Agent as undeliverable as of the fifth business day prior to the Expiration Date. The Subscription Agent will hold the proceeds from those sales for the benefit of those non-claiming Common Shareholders until the proceeds are either claimed or revert to their state of residence. There can be no assurance that the Dealer Manager will purchase or be able to complete the sale of any

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Rights, and neither the Fund nor the Dealer Manager have guaranteed any minimum sale price for the Rights. If a Record Date Shareholder does not utilize the services of the Subscription Agent and chooses to use another broker-dealer or other financial institution to sell Rights issued to that shareholder pursuant to the Offer, then the other broker-dealer or financial institution may charge a fee to sell the Rights.

        Other Transfers.    The Rights evidenced by a subscription certificate may be transferred in whole by endorsing the subscription certificate for transfer in accordance with the instructions accompanying the subscription certificate. A portion of the Rights evidenced by a single subscription certificate (but not fractional Rights) may be transferred by delivering to the Subscription Agent a subscription certificate properly endorsed for transfer, with instructions to register such portion of the Rights evidenced thereby in the name of the transferee and to issue a new subscription certificate to the transferee evidencing the transferred Rights. If this occurs, a new subscription certificate evidencing the balance of the Rights, if any, will be issued to the Record Date Shareholder or, if the Record Date Shareholder so instructs, to an additional transferee. The signature on the subscription certificate must correspond with the name as written upon the face of the subscription certificate in every particular, without alteration or enlargement, or any other change. A signature guarantee must be provided by an "eligible guarantor institution" (as defined in Rule 17Ad-15 of the Securities Exchange Act of 1934), subject to the standards and procedures adopted by the Fund.

        Record Date Shareholders wishing to transfer all or a portion of their Rights should allow at least ten (10) business days prior to the Expiration Date for: (i) the transfer instructions to be received and processed by the Subscription Agent; (ii) a new subscription certificate to be issued and transmitted to the transferee or transferees with respect to transferred Rights and to the transferor with respect to retained Rights, if any; and (iii) the Rights evidenced by the new subscription certificate to be exercised or sold by the recipients of the subscription certificate. Neither the Fund nor the Subscription Agent nor the Dealer Manager shall have any liability to a transferee or transferor of Rights if subscription certificates are not received in time for exercise or sale prior to the Expiration Date.

        Except for the fees charged by AST Fund Solutions, LLC, the information agent for the Offer (the "Information Agent"), the Subscription Agent and the Dealer Manager (which are expected to be paid by the Investment Adviser and not the Fund), all commissions, fees and other expenses (including brokerage commissions and transfer taxes) incurred or charged in connection with the purchase, sale or transfer of Rights will be for the account of the transferor of the Rights, and none of these commissions, fees or other expenses will be paid by the Fund, the Information Agent, the Investment Adviser, the Subscription Agent or the Dealer Manager. Rights holders who wish to purchase, sell, exercise or transfer Rights through a broker, bank or other party should first inquire about any fees and expenses that the holder will incur in connection with the transactions.

        The Fund anticipates that the Rights will be eligible for transfer through, and that the exercise of the primary subscription and the over-subscription may be effected through, the facilities of DTC or the Subscription Agent until 5:00 p.m., Eastern time, on the Expiration Date. Your broker, bank, trust company or other intermediary may impose a deadline for transferring Rights earlier than 5:00 p.m., Eastern time, on the Expiration Date.

Method for Exercising Rights

        Rights are evidenced by subscription certificates that will be mailed to Record Date Shareholders (except as described under "—Requirements for Foreign Shareholders") or, if their Common Shares are held by Cede & Co. or any other depository or nominee on their behalf, to Cede & Co. or such other depository or nominee. Rights may be exercised by completing and signing the subscription certificate and mailing it in the envelope provided, or otherwise delivering the completed and signed subscription certificate to the Subscription Agent, together with payment in full at the estimated

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Subscription Price for the Common Shares subscribed for by the Expiration Date as described under "—Payment For Shares". Rights may also be exercised by contacting your broker, bank, trust company or other intermediary, which can arrange, on your behalf, to guarantee delivery of a properly completed and executed subscription certificate pursuant to a notice of guaranteed delivery by the close of business on the second business day after the Expiration Date. A fee may be charged for this service. Completed subscription certificates and payments must be received by the Subscription Agent by 5:00 p.m., Eastern time, on the Expiration Date (unless delivery of subscription certificate is effected by means of a notice of guaranteed delivery as described under "—Payment for Shares") at the offices of the Subscription Agent at one of the addresses set forth under "—Subscription Agent". Your broker, bank, trust company or other intermediary may impose a deadline for exercising Rights earlier than 5:00 p.m., Eastern time, on the Expiration Date. Fractional Common Shares will not be issued upon exercise of Rights.

        Shareholders who are Record Owners.    Shareholders who are record owners of Common Shares can choose between either option set forth under "—Payment For Shares". If time is of the essence, option (2) will permit delivery of the subscription certificate after the Expiration Date.

        Investors whose Common Shares are Held by a Nominee.    Investors whose Common Shares are held by a nominee, such as a bank, broker, trustee or other intermediary, must contact that nominee to exercise their Rights. In that case, the nominee will complete the subscription certificate on behalf of the investor and arrange for proper payment by one of the methods set forth under "—Payment For Shares".

        Nominees.    Nominees, such as banks, brokers, trustees or depositories for securities, who hold Common Shares of the Fund for the account of others should notify the respective beneficial owners of such Common Shares as soon as possible to ascertain those beneficial owners' intentions and to obtain instructions with respect to the Rights. If the beneficial owner so instructs, the nominee should complete the subscription certificate and submit it to the Subscription Agent with the proper payment as described under "—Payment For Shares".

        Banks, brokers, trustees and other nominee holders of Rights will be required to certify to the Subscription Agent, before any Over-Subscription Privilege may be exercised with respect to any particular beneficial owner who is a Record Date Shareholder, as to the aggregate number of Rights exercised during the subscription period and the number of Common Shares subscribed for pursuant to the Over-Subscription Privilege by the beneficial owner, and that the beneficial owner exercised all the Rights issued to it pursuant to the Offer.

        Requirements for Foreign Shareholders.    Subscription certificates will not be mailed to Foreign Shareholders whose addresses are outside the United States (for these purposes, the United States includes the District of Columbia and the territories and possessions of the United States). The Subscription Agent will send a letter via regular mail to Foreign Shareholders to notify them of the Offer. The Rights of Foreign Shareholders will be held by the Subscription Agent for their accounts until instructions are received to exercise the Rights. If instructions have not been received by 5:00 p.m., Eastern time, on September 12, 2017, five (5) business days prior to the Expiration Date (or, if the subscription period is extended, on or before the fifth business day prior to the extended Expiration Date), the Rights of Foreign Shareholders will be transferred by the Subscription Agent to the Dealer Manager, who will either purchase the Rights or use its best efforts to sell the Rights. If the Dealer Manager declines to purchase the Rights, the Subscription Agent will attempt to sell such Rights in the open market. The net proceeds, if any, from the sale of those Rights by or to the Dealer Manager will be remitted to those Foreign Shareholders.

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Expenses of the Offer

        The Investment Adviser will bear the expenses of the Offer and no such expenses will be borne by the Fund or the Fund's Common Shareholders. These expenses include, but are not limited to, the Dealer Manager fee, reimbursement of the Dealer Manager's expenses, the expenses of preparing, printing and mailing the prospectus and Rights subscription materials for the Offer (including reimbursement of expenses of the Dealer Manager, Selling Group Members, Soliciting Dealers and other brokers, dealers and financial institutions), SEC registration fees and the fees assessed by service providers (including the cost of the Fund's counsel and independent registered public accounting firm) in connection with the Offer.

Distribution Arrangements

        UBS Securities LLC will act as Dealer Manager for this Offer. Under the terms and subject to the conditions contained in the Dealer Manager Agreement among the Dealer Manager, the Fund and the Investment Adviser, the Dealer Manager will provide financial structuring and solicitation services in connection with the Offer and will solicit the exercise of Rights and participation in the Over-Subscription Privilege. The Offer is not contingent upon any number of Rights being exercised. The Dealer Manager will also be responsible for forming and managing a group of selling broker-dealers (each a "Selling Group Member" and collectively the "Selling Group Members"), whereby each Selling Group Member will enter into a Selling Group Agreement with the Dealer Manager to solicit the exercise of Rights and to sell Common Shares purchased by the Selling Group Member from the Dealer Manager. In addition, the Dealer Manager will enter into a Soliciting Dealer Agreement with other soliciting broker-dealers (each a "Soliciting Dealer" and collectively the "Soliciting Dealers") to solicit the exercise of Rights. See "Compensation to Dealer Manager" for a discussion of fees and other compensation to be paid to the Dealer Manager, Selling Group Members and Soliciting Dealers in connection with the Offer.

        The Fund and the Investment Adviser have each agreed to indemnify the Dealer Manager for losses arising out of certain liabilities, including liabilities under the Securities Act. The Dealer Manager Agreement also provides that the Dealer Manager will not be subject to any liability to the Fund in rendering the services contemplated by the Dealer Manager Agreement except for any act of bad faith, willful misconduct or gross negligence of the Dealer Manager or reckless disregard by the Dealer Manager of its obligations and duties under the Dealer Manager Agreement.

        Prior to the expiration of the Offer, the Dealer Manager may independently offer for sale Common Shares it has acquired through purchasing and exercising the Rights, at prices it sets. The Dealer Manager is authorized to buy and exercise Rights (for delivery of Common Shares prior to the expiration of the Offer), including unexercised Rights of Record Date Shareholders whose record addresses are outside the United States that are held by the Subscription Agent and for which no instructions are received, and to sell Common Shares to the public or to Selling Group Members at the offering price set by the Dealer Manager from time to time. In addition, the Dealer Manager has the right to buy Rights offered to it by the Subscription Agent from electing Record Date Shareholders, and the Dealer Manager may purchase such Rights as principal or act as agent on behalf of its clients for the resale of such Rights.

        Record Date Shareholders who do not wish to exercise any or all of their Rights may instruct the Subscription Agent to try to sell any Rights they do not intend to exercise themselves. Subscription certificates evidencing the Rights to be sold by the Subscription Agent must be received by the Subscription Agent on or before 5:00 p.m., Eastern time, on September 12, 2017 (or, if the subscription period is extended, on or before 5:00 p.m., Eastern time, five (5) business days prior to the extended Expiration Date). Upon the timely receipt by the Subscription Agent of appropriate instructions to sell Rights, the Subscription Agent will ask the Dealer Manager if it will purchase the Rights. If the Dealer

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Manager purchases the Rights, the sales price paid by the Dealer Manager will be based upon the then current market price for the Rights. The proceeds from each of such sales to the Dealer Manager will be remitted to the Subscription Agent, which will hold such proceeds in an account segregated from the Subscription Agent's own funds pending distribution to each selling Record Date Shareholder. It is expected that following each such sale of Rights to the Dealer Manager, the proceeds from each such sale will be received by the Subscription Agent within three (3) business days of the sale and that the proceeds will then be remitted to the selling Record Date Shareholder within three (3) business days of receipt by the Subscription Agent.

        If the Dealer Manager declines to purchase the Rights of a Record Date Shareholder that have been duly submitted to the Subscription Agent for sale, the Subscription Agent will attempt to sell such Rights in the open market. If the Rights can be sold in such manner, all of such sales will be deemed to have been effected at the weighted-average price of all Rights sold by the Subscription Agent in such open market transactions throughout the subscription period. The proceeds from such sales will be held by the Subscription Agent in an account segregated from the Subscription Agent's own funds pending distribution to the selling Record Date Shareholders. It is expected that the proceeds of such open market sales will be remitted by the Subscription Agent to the selling Record Date Shareholders within five (5) business days following the Expiration Date.

        The Subscription Agent will also attempt to sell (either to the Dealer Manager or in open market transactions as described above) all Rights which remain unclaimed as a result of subscription certificates being returned by the postal authorities to the Subscription Agent as undeliverable as of the fifth (5th) business day prior to the Expiration Date. The Subscription Agent will hold the proceeds from those sales in an account segregated from the Subscription Agent's own funds for the benefit of such non-claiming Record Date Shareholders until such proceeds are either claimed or revert to the state.

        There can be no assurance that the Subscription Agent will be able to sell any Rights, and neither the Fund nor the Subscription Agent has guaranteed any minimum sales price for the Rights. If a Record Date Shareholder does not utilize the services of the Subscription Agent and chooses to use another broker-dealer or other financial institution to sell Rights, then the other broker-dealer or financial institution may charge a fee to sell the Rights. If a Record Date Shareholder does not utilize the services of the Subscription Agent and chooses to use another broker-dealer or other financial institution to sell Rights, then the other broker-dealer or financial institution may charge a fee to sell the Rights.

        Although the Dealer Manager may realize gains and losses in connection with purchases and sales of Common Shares, such offering of Common Shares is intended by the Dealer Manager to facilitate the Offer, and any such gains or losses are not expected to be material to the Dealer Manager. The Dealer Manager's fee for its financial structuring and soliciting services is independent of any gains or losses that may be realized by the Dealer Manager through the purchase and exercise of the Rights and the sale of Common Shares.

        In the ordinary course of their businesses, the Dealer Manager and/or its affiliates may engage in investment banking or financial transactions with the Fund, the Investment Adviser and their affiliates. In addition, in the ordinary course of their businesses, the Dealer Manager and/or its affiliates may, from time to time, own securities of the Fund or its affiliates.

        The principal business address of the Dealer Manager is 1285 Avenue of the Americas, New York, New York 10019.

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Compensation to Dealer Manager

        Pursuant to the Dealer Manager Agreement, the Investment Adviser, and not the Fund, has agreed to pay the Dealer Manager a fee for its financial structuring and solicitation services equal to 3.75% of the aggregate Subscription Price for Shares issued pursuant to the Offer.

        The Dealer Manager will reallow to Selling Group Members in the Selling Group to be formed and managed by the Dealer Manager selling fees equal to 2.50% of the Subscription Price for each Common Share issued pursuant to the Offer or the Over-Subscription Privilege as a result of their selling efforts. In addition, the Dealer Manager will reallow to Soliciting Dealers that have executed and delivered a Soliciting Dealer Agreement and have solicited the exercise of Rights, solicitation fees equal to 0.50% of the Subscription Price for each Common Share issued pursuant to the exercise of Rights as a result of their soliciting efforts, subject to a maximum fee based on the number of Common Shares held by such Soliciting Dealer through DTC on the Record Date. Fees will be paid to the broker-dealer designated on the applicable portion of the subscription certificates or, in the absence of such designation, to the Dealer Manager.

        In addition, the Investment Adviser, and not the Fund, has agreed to pay the Dealer Manager an amount up to $100,000 as a partial reimbursement of its expenses incurred in connection with the Offer. The fees described above are one-time fees payable on each date on which the Fund issues Common Shares after the Expiration Date with respect to the Dealer Manager, and on or before the tenth business day following the day the Fund issues Common Shares after the Expiration Date with respect to a Selling Group Member or Soliciting Dealer. The Investment Adviser, and not the Fund, will also pay expenses relating to the printing or other production, mailing and delivery expenses incurred in connection with materials related to the Offer, including all reasonable out-of-pocket fees and expenses, if any and not to exceed $100,000, incurred by the Dealer Manager, Selling Group Members, Soliciting Dealers and other brokers, dealers and financial institutions in connection with their customary mailing and handling of materials related to the Offer to their customers. No other fees will be payable by the Fund or the Investment Adviser to the Dealer Manager in connection with the Offer.

Subscription Agent

        Computershare Inc. and Computershare Trust Company, N.A. collectively, serve as the Subscription Agent for the Offer. The Subscription Agent will receive for its administrative, processing, invoicing and other services a project management fee of $20,000, plus certain per transaction fees and reimbursement for all out-of-pocket expenses related to the Offer. The fees and expenses of the Subscription Agent are included in the fees and expenses of the Offer and therefore will be borne by the Investment Adviser, and not the Fund or its Common Shareholders. Questions regarding the subscription certificates should be directed by mail to the Information Agent at 55 Challenger Road, Suite 201, Ridgefield Park, NJ 07660. Shareholders may also subscribe for the Offer by contacting their broker dealer, trust company, bank or other nominee.

        Completed subscription certificates must be sent together with proper payment of the estimated Subscription Price for all Common Shares subscribed for in the primary subscription and the Over-Subscription Privilege (for Record Date Shareholders) to the Subscription Agent by one of the methods described below. Alternatively, Rights holders may arrange for their financial intermediaries to send notices of guaranteed delivery by email to Computershare to be received by the Subscription Agent prior to 5:00 p.m., Eastern time, on the Expiration Date. The Fund will accept only properly completed and executed subscription certificates actually received at any of the addresses listed below, prior to 5:00 p.m., Eastern time, on the Expiration Date, or by the close of business on the second

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business day after the Expiration Date following timely receipt of a notice of guaranteed delivery. See "—Payment for Shares".

        The Fund will honor only subscription certificates received by the Subscription Agent prior to 5:00 p.m., Eastern time, on the Expiration Date at one of the addresses listed above. Delivery to an address other than those listed above will not constitute good delivery.

Information Agent

        The Information Agent for the Offer is AST Fund Solutions, LLC. If you have questions or need further information about the Offer, please write the Information Agent at 55 Challenger Road, Suite 201, Ridgefield Park, NJ 07660, or call (877) 478-5039. Any questions or requests for assistance concerning the method of subscribing for Common Shares or additional copies of this prospectus or subscription certificates should be directed to the Information Agent. Shareholders may also contact their brokers or nominees for information with respect to the Offer.

        The Information Agent will receive a fee estimated to be approximately $8,500 for its services, plus reimbursement for all out-of-pocket expenses related to the Offer. The fees and expenses of the Information Agent are included in the fees and expenses of the Offer and therefore will be borne by the Investment Adviser, and not the Fund.

Expiration of the Offer

        The Offer will expire at 5:00 p.m., Eastern time, on September 19, 2017, unless the Fund extends the subscription period. Rights will expire on the Expiration Date and may not be exercised after that date. If the Fund extends the subscription period, the Fund will make an announcement as promptly as practicable. This announcement will be issued no later than 9:00 a.m., Eastern time, on the next business day following the previously scheduled Expiration Date. Without limiting the manner in which the Fund may choose to make this announcement, the Fund will not, unless otherwise required by law, have any obligation to publish, advertise or otherwise communicate this announcement other than by making a release to the Dow Jones News Service or any other means of public announcement as the Fund may deem proper.

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Payment for Shares

        Rights holders who wish to acquire Common Shares pursuant to the primary subscription and the Over-Subscription Privilege may choose between the following methods of payment:

        (1)   A Rights holder can send the properly completed and executed subscription certificate together with payment for the Common Shares subscribed for during the subscription period and, if eligible, for any additional Common Shares subscribed for pursuant to the Over-Subscription Privilege, to the Subscription Agent based upon an estimated Subscription Price of $18.64 per Common Share. A subscription will be accepted when payment, together with the executed subscription certificate, is received by the Subscription Agent at one of the addresses set forth under "—Subscription Agent"; the payment and the properly completed and executed subscription certificate must be received by the Subscription Agent by 5:00 p.m., Eastern time, on the Expiration Date. The Subscription Agent will deposit all checks received by it for the purchase of Common Shares into a segregated account of the Fund pending proration and distribution of Common Shares. A payment pursuant to this method must be in U.S. dollars by check drawn on a bank located in the United States, must be payable to "Computershare" and must accompany a properly completed and executed subscription certificate for such subscription to be accepted.

        (2)   Alternatively, a subscription will be accepted by the Subscription Agent if, by 5:00 p.m., Eastern time, on the Expiration Date, the Subscription Agent has received a notice of guaranteed delivery by email from a bank, a trust company or an NYSE American member guaranteeing delivery of a properly completed and executed subscription certificate. In order for the notice of guarantee to be valid, full payment for the Common Shares at the estimated Subscription Price must be received with the notice. The Subscription Agent will not honor a notice of guaranteed delivery unless a properly completed and executed subscription certificate is received by the Subscription Agent by the close of business on the second business day after the Expiration Date.

        On the confirmation date, which will be eight (8) business days following the Expiration Date, a confirmation will be sent by the Subscription Agent to each Rights holder exercising its Rights (or, if a Rights holder's Common Shares are held by DTC or any other depository or nominee, to DTC and/or that other depository or nominee) showing (i) the number of Common Shares acquired during the subscription period, (ii) the number of Common Shares, if any, acquired pursuant to the Over-Subscription Privilege, (iii) the per Common Share and total purchase price for the Common Shares and (iv) any additional amount payable to the Fund by the Rights holder or any excess to be refunded by the Fund to the Rights holder, in each case based on the Subscription Price as determined on the Expiration Date. Any additional payment required from a Rights holder must be received by the Subscription Agent within ten (10) business days after the confirmation date (which confirmation date is September 29, 2017, unless the subscription period is extended). Any excess payment to be refunded by the Fund to a Rights holder will be mailed by the Subscription Agent to such Rights holder as promptly as practicable. All payments by a Rights holder must be in U.S. dollars by check drawn on a bank located in the United States and payable to "Computershare".

        Whichever of the two methods described above is used, issuance and delivery of the Common Shares subscribed for are contingent upon actual payment for such Common Shares. No certificates will be issued or delivered with respect to Common Shares issued and sold in the Offer.

        Rights holders who have exercised their Rights will have no right to rescind their subscription after receipt of the completed subscription certificate together with payment for Common Shares by the Subscription Agent, except as described under "—Notice of Net Asset Value Decline".

        If a Rights holder who acquires Common Shares during the subscription period or pursuant to the Over-Subscription Privilege (for Record Date Shareholders) does not make payment of any amounts due by the Expiration Date, the Fund reserves the right to take any or all of the following actions

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through all appropriate means: (i) find other Record Date Shareholders for the subscribed and unpaid-for Common Shares; (ii) apply any payment actually received by the Fund toward the purchase of the greatest whole number of Common Shares that could be acquired by the Rights holder upon exercise of such Rights acquired during the subscription period or pursuant to the Over-Subscription Privilege; and/or (iii) exercise any and all other rights or remedies to which the Fund may be entitled, including, without limitation, the right to set off against payments actually received by it with respect to such subscribed Common Shares.

        The method of delivery of completed subscription certificates and payment of the Subscription Price to the Subscription Agent will be at the election and risk of exercising Rights holders, but if sent by mail it is recommended that such forms and payments be sent by registered mail, properly insured, with return receipt requested, and that a sufficient number of days be allowed to ensure delivery to the Subscription Agent and clearance of payment by 5:00 p.m., Eastern time, on the Expiration Date. Because uncertified personal checks may take at least five (5) business days to clear, exercising Rights holders are strongly urged to pay, or arrange for payment, by means of certified or cashier's check with the shareholder's name and Computershare account number identified on the check.

        All questions concerning the timeliness, validity, form and eligibility of any exercise of Rights will be determined by the Fund, which determinations will be final and binding. The Fund, in its sole discretion, may waive any defect or irregularity, or permit a defect or irregularity to be corrected within such time as it may determine, or reject the purported exercise of any Right. Subscriptions will not be deemed to have been received or accepted until substantially all irregularities have been waived or cured within such time as the Fund determines in its sole discretion. The Fund will not be under any duty to give notification of any defect or irregularity in connection with the submission of subscription certificates or incur any liability for failure to give such notification.

Notice of Net Asset Value Decline

        The Fund has, pursuant to the SEC's regulatory requirements, undertaken to suspend the Offer until the Fund amends this Prospectus Supplement if, after August 2, 2017 (the effective date of the Fund's registration statement relating to this Offer), the Fund's NAV declines more than 10% from the Fund's NAV as of that date. In that event, the Expiration Date will be extended and the Fund will notify Record Date Shareholders of any such decline and permit Rights holders to cancel their exercise of Rights.

Delivery of Shares

        Participants in the Fund's Dividend Reinvestment Plan (as defined in this Prospectus Supplement) will have any Common Shares acquired pursuant to the Offer credited to their shareholder dividend reinvestment accounts in the Dividend Reinvestment Plan. Common Shareholders whose Common Shares are held of record by DTC or by any other depository or nominee on their behalf or their broker-dealers' behalf will have any Common Shares acquired during the subscription period credited to the account of DTC or other depository or nominee. No certificates will be issued or delivered with respect to Common Shares issued and sold in the Offer.

U.S. Federal Income Tax Consequences

        The following is a general summary of the U.S. federal income tax consequences of the Offer to Record Date Shareholders and other Rights holders who are "U.S. Persons" as defined below. The following summary supplements the discussion set forth in the accompanying Prospectus and Statement of Additional Information under the headings "Taxation" and is subject to the qualifications and assumptions set forth therein. Please refer to such discussion for a general description of the consequences of investing in Common Shares.

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        The summary below is based upon the Internal Revenue Code of 1986 (the "Code"), Treasury regulations promulgated thereunder ("Treasury regulations"), judicial authorities, published positions of the Internal Revenue Service (the "IRS") and other applicable authorities, all as in effect on the date hereof and all of which are subject to change or differing interpretations possibly with retroactive effect. The discussion does not address all of the tax consequences that may be relevant to a particular Record Date Shareholder or other Rights holder, including those subject to special treatment under U.S. federal income tax laws such as financial institutions, insurance companies, broker-dealers, tax-exempt organizations, foreign persons, or persons holding Rights or Common Shares as part of a straddle or conversion transaction. This discussion is limited to Record Date Shareholders that hold Common Shares as capital assets. Except as otherwise stated herein, no ruling has been or will be sought from the IRS regarding any matter discussed herein. No assurance can be given that the IRS would not assert, or that a court would not sustain, a position contrary to any of the tax aspects set forth below. Holders of Rights on the Record Date should consult their tax advisors as to the U.S. federal income tax consequences of the Offer that are relevant to their particular situations, as well as the effects of state, local and non-U.S. tax laws.

        For purposes of this discussion, a U.S. person means a holder that is, for U.S. federal income tax purposes, any one of the following:

•

an individual who is a citizen or resident of the U.S.;



•

a corporation or other entity treated as a corporation that is created or organized in or under the laws of the U.S. or any state thereof or the District of Columbia;



•

a trust if a court within the U.S. is able to exercise primary supervision over the administration of the trust and one or more U.S. persons have the authority to control all substantial decisions of the trust or the trust has a valid election in effect under applicable Treasury regulations to be treated as a U.S. person; or



•

an estate, the income of which is includible in gross income for U.S. federal income tax purposes regardless of its source.

        If a partnership (or any other entity treated as a partnership or other pass-through entity for U.S. federal income tax purposes) holds a Right, the U.S. federal income tax treatment of a partner generally will depend upon the status of the partner and the activities of the partnership. Partners and partnerships holding Rights should consult their tax advisors concerning the U.S. federal income and other tax consequences relevant to their particular situation.

        Issuance of Rights, Basis and Holding Period.    Record Date Shareholders should not recognize taxable income in connection with the receipt of a Right pursuant to the Offer, provided that the distribution does not have the result of causing some Record Date Shareholders to receive an increase in their proportionate interest in the assets or earnings and profits of the Fund and other Record Date Shareholders to receive cash or property. The distribution of the Rights in the Offer should not have the effect of causing some Record Date Shareholders to receive an increase in their proportionate interest in the assets or earnings and profits of the Fund and other Record Date Shareholders to receive cash or property. Therefore, no income should be recognized by any Record Date Shareholders in connection with the issuance of the Rights pursuant to the Offer.

        Except as provided in the following sentence, the basis of the Rights received by a Record Date Shareholder will be zero and the basis of the Common Share with respect to which the Right was issued (the "Old Common Share") will remain unchanged. The Record Date Shareholder must allocate a portion of the basis of the Old Common Share to the Right in proportion to their respective fair market values on the date of distribution if (i) either (a) the fair market value of the Right on the date of distribution is at least 15% of the fair market value of the Old Common Share on that date, or (b) the Record Date Shareholder affirmatively elects (in the manner set out in Treasury regulations) to

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allocate to the Right a portion of the basis of the Old Common Share and (ii) the Right does not expire unexercised in the hands of the Record Date Shareholder (i.e., the Record Date Shareholder either exercises or sells the Right following its issuance).

        The basis of a Right purchased in the market will generally be its purchase price.

        The holding period of the Rights received in the Offer will include the holder's holding period for the Common Shares with respect to which the Rights were issued.

        Expiration of the Rights.    Holders who receive Rights in the Offer with respect to their Common Shares and who allow such Rights to expire unexercised will not recognize any gain or loss, and no adjustment will be made to the basis of the holder's Common Shares.

        If a Right that has been purchased in the market expires unexercised, the holder will recognize a loss equal to the basis of the Right. If the Right was held as a capital asset, loss on the expiration of the Right generally will be a capital loss.

        Sale of the Rights.    Upon the sale of a Right, the seller will recognize gain or loss equal to the difference between the amount realized on the sale and the seller's basis in the Right. Any gain or loss on the sale of a Right will be capital gain or loss if the Right is held as a capital asset (which in the case of Rights issued to Record Date Shareholders will depend on whether the Old Common Share is held as a capital asset), and will be a long-term capital gain or loss if the holding period of the Right is deemed to exceed one year.

        Exercise of the Rights, Basis and Holding Period of Acquired Shares.    No gain or loss will be recognized by a Rights holder upon the exercise of a Right, and the basis of any Common Share acquired upon exercise of the Right (the "New Common Share") will equal the sum of (i) the basis, if any, of the Right and (ii) the Subscription Price for the New Common Share. The holding period for the New Common Share acquired through exercise of the Right will begin on the date of exercise of the Right (or, in the case of a Right purchased in the market, potentially the day after the date of exercise).

Employee Benefit Plan Considerations

        Common Shareholders that are employee benefit plans subject to the Employee Retirement Income Security Act of 1974, as amended ("ERISA") (including corporate savings and 401(k) plans each, an ERISA Plan), Keogh plans of self-employed individuals, Individual Retirement Accounts ("IRAs") and other plans subject to Section 4975 of the Code (each a "Plan" and collectively, the "Plans") should be aware that additional contributions of cash to the Plan (other than rollover contributions or trustee-to-trustee transfers from other Plans) made in order to exercise Rights would be treated as Plan contributions and, when taken together with contributions previously made, may subject a Plan to excise taxes for excess or nondeductible contributions. In the case of Plans qualified under Section 401(a) of the Code and certain other plans, additional cash contributions could cause the maximum contribution limitations of Section 415 of the Code or other qualification rules to be violated. Plans contemplating the receipt of additional cash contributions to exercise Rights should consult with their counsel prior to receiving or using such contributions.

        Plans and other tax exempt entities, including governmental plans, should also be aware that if they borrow in order to finance their exercise of Rights, they may become subject to the tax on unrelated business taxable income under Section 511 of the Code. If any portion of an IRA is used as security for a loan to the individual for whose benefit the IRA is established, the portion so used is also treated as distributed to such individual.

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        Each fiduciary of a Plan should consider, to the extent applicable, the fiduciary standards of ERISA and the Code in the context of the Plan's particular circumstances before making any decision regarding the exercise or other disposition of rights, and any investment in Common Shares as a consequence thereof. Under ERISA and the Code, any person who exercises any discretionary authority or control over the administration of a Plan or the management or disposition of the assets of a Plan, or who renders investment advice for a fee or other compensation to a Plan, is generally considered to be a fiduciary of the Plan. Accordingly, among other factors, the fiduciary should consider whether the exercise and investment would satisfy the prudence and diversification requirements of ERISA, to the extent applicable, and would be consistent with its fiduciary responsibilities, and the documents and instruments governing the Plan.

        To the extent the Fund, the Investment Adviser or certain of their respective affiliates might be considered a "party in interest" or a "disqualified person" with respect to a Plan, prohibited transactions may arise in connection with exercises or transfers of Rights pursuant to an available exemption. In this regard the U.S. Department of Labor has issued prohibited transaction class exemptions that may apply. These exemptions include transactions effected on behalf of a Plan by a "qualified professional asset manager" (prohibited transaction exemption 84-14) or an "in-house asset manager" (prohibited transaction exemption 96-23), transactions involving insurance company general accounts (prohibited transaction exemption 95-60), transactions involving insurance company pooled separate accounts (prohibited transaction exemption 90-1), and transactions involving bank collective investment funds (prohibited transaction exemption 91-38). In addition, Section 408(b)(17) of ERISA and Section 4975(d)(20) of the Code provide relief from the prohibited transaction provisions of ERISA and Section 4975 of the Code for certain transactions, provided that neither the issuer of the securities nor any of its affiliates (directly or indirectly) have or exercise any discretionary authority or control or render any investment advice with respect to the assets of any Plan involved in the transaction and provided further that the Plan receives no less and pays no more than "adequate consideration" (within the meaning of Section 408(b)(17) of ERISA and Section 4975(f)(10) of the Code). There can be no assurance that all of the conditions of any such exemptions will be satisfied with respect to transactions involving Rights or any Common Shares obtained pursuant to any Rights.

        Governmental plans, certain church plans and non-U.S. plans may not be subject to the prohibited transaction provisions of ERISA or the Code but may be subject to similar laws ("Similar Laws"). Fiduciaries of any such plans should consult with counsel before exercise or transfer of Rights.

        Because of the foregoing, the person making the decision on behalf of a Plan or a governmental, church or foreign plan will be deemed, by tendering the Notes, to represent on behalf of itself and the plan that the tendering of the Notes will not result in a non-exempt prohibited transaction under ERISA or Section 4975 of the Code or any applicable Similar Law.

        In addition, the person making any decision on behalf of a Plan to exercise or transfer Rights (the "Plan Fiduciary"), will be deemed to have represented, warranted and acknowledged that (1) neither the Fund nor the Investment Adviser, nor any of their respective affiliates (the "Transaction Parties") has provided or will provide advice with respect to the disposition of Rights by the Plan, other than to the Plan Fiduciary which is independent of the Transaction Parties, and the Plan Fiduciary either: (a) is a bank as defined in Section 202 of the Investment Advisers Act of 1940 (the "Advisers Act"), or similar institution that is regulated and supervised and subject to periodic examination by a state or federal agency; (b) is an insurance carrier which is qualified under the laws of more than one state to perform the services of managing, acquiring or disposing of assets of a Plan; (c) is an investment adviser registered under the Advisers Act, or, if not registered an as investment adviser under the Advisers Act by reason of paragraph (1) of Section 203a of the Advisers Act, is registered as an investment adviser under the laws of the state in which it maintains its principal office and place of business; (d) is a broker-dealer registered under the Securities Exchange Act of 1934, as amended; or (e) has, and at all times during the transactions contemplated in connection with the Tender Offer will

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have, total assets of at least U.S. $50,000,000 under its management or control (provided that this clause (e) shall not be satisfied if the Plan Fiduciary is either (i) the owner or a relative of the owner of the individual retirement account that is tendering the Notes, or (ii) a participant or beneficiary of the Plan tendering the Notes in such capacity); (2) the Plan Fiduciary is capable of evaluating investment risks independently, both in general and with respect to particular transactions and investment strategies, including the tendering of the Notes by the Plan; (3) the Plan Fiduciary is a "fiduciary" with respect to the Plan within the meaning of Section 3(21) of ERISA, Section 4975 of the Code, or both, and is responsible for exercising independent judgment in evaluating the Plan's tendering of the Notes; (4) none of the Transaction Parties has exercised any authority to cause the Plan to tender the Notes or to negotiate the terms of the Plan's tendering of the Notes; (5) none of the Transaction Parties receives a fee or other compensation from the Plan or Plan Fiduciary for the provision of investment advice in connection with the Plan's decision to tender the Notes; and (6) the Plan Fiduciary has been informed by the Transaction Parties: (a) that none of the Transaction Parties is undertaking to provide impartial investment advice or to give advice in a fiduciary capacity, and that no such entity has given investment advice or otherwise made a recommendation, in connection with the Plan's exercise or other disposition of Rights; and (b) of the existence and nature of the Transaction Parties' financial interests in the Plan's tendering of the Notes. The above representations are intended to comply with the Department of Labor's regulation Sections 29 C.F.R. 2510.3-21(a) and (c)(1) as promulgated on April 8, 2016 (81 Fed. Reg. 20,997). If these regulations are revoked, repealed or no longer effective, these representations shall be deemed to be no longer in effect. None of the Transaction Parties is undertaking to provide impartial investment advice, or to give advice in a fiduciary capacity, in connection with the Rights by any Plan.

        ERISA contains fiduciary responsibility requirements, and ERISA and the Code contain prohibited transaction rules that may impact the exercise or transfer of Rights. Due to the complexity of these rules and the penalties for non-compliance, Plans should consult with their counsel regarding the consequences of their exercise or transfer of Rights under ERISA and the Code.

Benefits to the Investment Adviser

        The Investment Adviser will benefit from the Offer, in part, because the investment advisory fee paid by the Fund to the Investment Adviser is based on the Fund's Managed Assets. It is not possible to state precisely the amount of additional compensation the Investment Adviser will receive as a result of the Offer because it is not known how many Common Shares of the Fund will be subscribed for and because the proceeds of the Offer will be invested in additional portfolio securities which will fluctuate in value. However, assuming (i) all Rights are exercised, (ii) the Fund's average daily net asset value during the twelve-month period beginning October 1, 2017 is $25.23 per Common Share (the NAV per Common Share on August 17, 2017), (iii) the Subscription Price is $18.64 per Common Share, and (iv) for purposes of this example, the Fund increases the amount of leverage outstanding while maintaining approximately the same percentage of total assets attributable to leverage, the Investment Adviser would receive additional investment advisory fees of approximately $565,602 for the twelve-month period beginning October 1, 2017, and would continue to receive additional investment advisory fees as a result of the Offer, based on the Fund's Managed Assets attributable to the Common Shares issued in the Offer and related additional leverage, thereafter.

Investment Considerations and Dilution

        Upon completion of the Offer, Common Shareholders who do not exercise their Rights fully will own a smaller proportional interest in the Fund than would be the case if the Offer had not been made. In addition, because the Subscription Price per Common Share is likely to be less than the Fund's NAV per Common Share, the Offer will likely result in a dilution of the Fund's NAV per Common Share for all Common Shareholders, irrespective of whether they exercise all or any portion

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of their Rights. Although it is not possible to state precisely the amount of such a decrease in value, because it is not known at this time what the Subscription Price will be, what the NAV per Common Share will be on the Expiration Date or what proportion of Common Shares will be subscribed for, the dilution could be substantial. For example, assuming that all Rights are exercised, that the Fund's NAV on the Expiration Date is $25.23 per Common Share (the NAV per Common Share on August 17, 2017), and that the Subscription Price is $18.64 per Common Share, the Fund's NAV per Common Share on this date would be reduced by approximately $1.65 per Common Share. This estimate does not reflect any reduction in net assets as a result of the Dealer Manager fee of $1,782,801 or other estimated offering expenses (estimated at approximately $568,000) since the Investment Adviser, and not the Fund, has agreed to pay the Dealer Manager fee and such other offering expenses. Record Date Shareholders will experience a decrease in the NAV per Common Share held by them, irrespective of whether they exercise all or any portion of their Rights. The distribution of transferable Rights, which may themselves have value, will afford non-participating Common Shareholders the potential of receiving a cash payment upon the sale of the Rights, receipt of which may be viewed as partial compensation for the economic dilution of their interests, although there can be no assurance that a market for the Rights will develop.

        The fact that the Investment Adviser, and not the Fund, is paying the Dealer Manager fee and all other offering expenses (which include, among other items, reimbursement of the Dealer Manager's expenses, the expenses of preparing, printing and mailing the prospectus and Rights subscription materials for the Offer (including reimbursement of expenses of the Dealer Manager, Selling Group Members, Soliciting Dealers and other brokers, dealers and financial institutions), SEC registration fees and the fees assessed by service providers (including the cost of the Fund's counsel and independent registered public accounting firm)) may reduce the effects of dilution as a result of the Offer since the Fund's net assets will not additionally be reduced by the expenses of conducting the Offer and since the Fund will receive as proceeds from the Offer the full Subscription Price for each Common Share issued.

RISKS RELATED TO THE OFFER

        Risk is inherent in all investing. Therefore, before investing in the Common Shares you should consider the risks carefully. See "Risk Factors and Special Considerations" in the Prospectus and the special risks and considerations set out below.

Dilution Risk

        As a result of this Offer, it is anticipated that even if you fully exercise your Rights, you should expect to incur immediate economic dilution and, if you do not exercise all of your Rights, you will incur voting dilution. To the extent that the number of Common Shares outstanding after the Offer will have increased proportionately more than the increase in the size of the Fund's net assets, you will, at the completion of the Offer, experience immediate dilution of net asset value. The percentage increase in Common Shares outstanding that will occur if all the Rights are exercised is 33¹/3%. If the Subscription Price for the Offer is less than the Fund's NAV per Common Share as of the Expiration Date, you would experience immediate dilution of net asset value as a result of the Offer. If the Subscription Price is substantially less than the current NAV per Common Share at the expiration of the Offer, such dilution could be substantial. It is anticipated that the existing Common Shareholders will experience immediate dilution even if they fully exercise their Rights. This dilution of NAV will disproportionately affect Common Shareholders who do not exercise their Rights. The Fund cannot state precisely the amount of any decrease because it is not known at this time how many Common Shares will be subscribed for or what the net asset value or market price of the Fund's Common Shares will be on the Expiration Date or what the Subscription Price will be. For example, based on the Fund's NAV and market price on August 17, 2017, the Subscription Price would be less than NAV and

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there would be dilution. Assuming full exercise of the Rights being offered at the Subscription Price and assuming that the Expiration Date was August 17, 2017, it is estimated that the per share dilution resulting from the Offer, as of August 17, 2017, would be $1.65, or 6.5%.

        In addition to the economic dilution described above, if you do not exercise all of your Rights, you will incur voting dilution as a result of this Offer. This voting dilution will occur because you will own a smaller proportionate interest in the Fund after the Offer than you owned prior to the Offer.

        The fact that the Rights are transferable may reduce the effects of dilution as a result of the Offer. Rights holders can transfer or sell their Rights. The cash received from the sale of Rights may be viewed as partial compensation for any possible dilution. There can be no assurances, however, that a market for the Rights will develop or that the Rights will have any value in that market. Additionally, the fact that the Investment Adviser, and not the Fund, is paying the Dealer Manager fee and all other offering expenses (which include, among other items, reimbursement of the Dealer Manager's expenses, the expenses of preparing, printing and mailing the prospectus and Rights subscription materials for the Offer (including reimbursement of expenses of the Dealer Manager, Selling Group Members, Soliciting Dealers and other brokers, dealers and financial institutions), SEC registration fees and the fees assessed by service providers (including the cost of the Fund's counsel and independent registered public accounting firm)) may reduce the effects of dilution as a result of the Offer since the Fund's net assets will not additionally be reduced by the expenses of conducting the Offer and since the Fund will receive as proceeds from the Offer the full Subscription Price for each Common Share issued.

Risks of Investing in Rights to Purchase Common Shares

        As with any stock, the price of the Fund's Common Shares fluctuates with market conditions and other factors. Shares of closed-end funds such as the Fund frequently trade at a discount to NAV. Since inception, the Fund's Common Shares have frequently traded at a discount in relation to NAV. See "Description of Common Shares" in the accompanying Prospectus. This characteristic is a risk separate and distinct from the risk that the Fund's net asset value could decrease as a result of its investment activities and may be greater for shareholders expecting to sell their Common Shares in a relatively short period of time following completion of this Offer.

        If the Formula Price is less than 70% of NAV on the Expiration Date, then the Subscription Price will likely be greater than the market price of a Common Share on that date. In addition, the Formula Price, even if above 70% of NAV, may still be above the market price of a Common Share on the Expiration Date. If either event occurs, the Rights will have no value, and a person who exercises Rights will experience an immediate loss of value.

ADDITIONAL SUPPLEMENTAL INFORMATION

        As of June 30, 2017, the Fund had outstanding 7,651,507 common shares, and 64 Series M, 438 Series T, 47 Series W, 91 Series Th and 27 Series F auction rate preferred shares (collectively, the "Auction Rate Preferred Shares") with a total liquidation preference of $16,675,000 ($25,000 per share).

        As of June 30, 2017, the Fund had $60,000,000 in outstanding borrowings on a revolving credit facility (the "Facility") with BNP Paribas Prime Brokerage International Limited ("PBL"). During the six months ended June 30, 2017 the average outstanding daily balance under the Facility was $60,000,000 at a weighted average borrowing cost of 2.09%. As of June 30, 2017, the Fund had pledged portfolio securities with a market value of $126,777,169 as collateral for the Facility. The Facility also permits, subject to certain conditions, PBL to rehypothecate portfolio securities pledged by the Fund up to the amount of the loan balance outstanding. As of June 30, 2017 the aggregated value of rehypothecated securities was $35,332,714. Those rehypothecated securities were included among the portfolio securities pledged by the Fund as collateral for the Facility. During the six months ended June 30, 2017, the Fund earned $10,403 in fees from rehypothecated securities.

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Effects of Leverage—as of June 30, 2017

        As of June 30, 2017, leverage in the form of the Auction Rate Preferred Shares and the Facility represented approximately 28.0% of the Fund's Managed Assets.

        Assuming that leverage will (1) be equal in amount to approximately 28.0% of the Fund's Managed Assets after such borrowings, and (2) charge interest or involve payments at a rate set by an interest rate transaction at an annual average rate of 2.37%, then the income generated by the Fund's portfolio (net of estimated expenses) must exceed approximately 2.2% of the Fund's Managed Assets in order to cover such interest payments or payment rates and other expenses specifically related to leverage. Of course, these numbers are merely estimates, used for illustration. Actual dividend rates, interest or payment rates may vary frequently and may be significantly higher or lower than the rate estimated above.

        The following table is furnished in response to the requirements of the SEC. It is designed to illustrate the effect of leverage on your common share annual total return, assuming investment portfolio total returns (comprised of income, net expenses and changes in the value of investments held in our 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. The table assumes leverage in an aggregate amount equal to approximately 28.0% of the Fund's Managed Assets and a cost of leverage equal to 2.37% per year.

        Common share total return is composed of two elements—the common share distributions paid by the Fund (the amount of which is largely determined by the taxable income of the Fund (including realized gains or losses) after paying interest on any debt and/or distributions on any preferred shares) and unrealized gains or losses on the value of the securities the Fund owns. As required by SEC rules, the table assumes that the Fund is more likely to suffer capital losses than to enjoy total return. For example, to assume a total return of 0% the Fund must assume that the income it receives on its investments is entirely offset by expenses and losses in the value of those investments.

        During the time in which the Fund uses leverage, the amount of the fees paid to the Investment Adviser will be higher than if the Fund did not use leverage because these fees will be calculated based on the Fund's Managed Assets.

Estimated Effects of Leverage after the Offer

        Assuming the net proceeds of the Offer are $47,541,357, leverage in the form of the Auction Rate Preferred Shares and the Facility are expected to represent approximately 30.1% of the Fund's Managed Assets.

        Assuming that leverage will (1) be equal in amount to approximately 30.1% of the Fund's Managed Assets after such borrowings, and (2) charge interest or involve payments at a rate set by an interest rate transaction at an annual average rate of 2.34%, then the income generated by the Fund's portfolio (net of estimated expenses) must exceed approximately 1.9% of the Fund's Managed Assets in order to cover such interest payments or payment rates and other expenses specifically related to leverage. Of course, these numbers are merely estimates, used for illustration. Actual dividend rates, interest or payment rates may vary frequently and may be significantly higher or lower than the rate estimated above.

        The following table is furnished in response to the requirements of the SEC. It is designed to illustrate the effect of leverage on your common share annual total return, assuming investment portfolio total returns (comprised of income, net expenses and changes in the value of investments held

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in our 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. The table assumes leverage in an aggregate amount equal to approximately 30.1% of the Fund's Managed Assets and a cost of leverage equal to 2.34% per year.

        Common share total return is composed of two elements—the common share distributions paid by the Fund (the amount of which is largely determined by the taxable income of the Fund (including realized gains or losses) after paying interest on any debt and/or distributions on any preferred shares) and unrealized gains or losses on the value of the securities the Fund owns. As required by SEC rules, the table assumes that the Fund is more likely to suffer capital losses than to enjoy total return. For example, to assume a total return of 0% the Fund must assume that the income it receives on its investments is entirely offset by expenses and losses in the value of those investments.

        During the time in which the Fund uses leverage, the amount of the fees paid to the Investment Adviser will be higher than if the Fund did not use leverage because these fees will be calculated based on the Fund's Managed Assets.

LEGAL MATTERS

        Certain legal matters will be passed on by Skadden, Arps, Slate, Meagher & Flom LLP, New York, New York, and Venable LLP, 750 E. Pratt Street, Suite 900, Baltimore, MD 21202 as special counsel to the Fund in connection with the Offer. Certain legal matters will be passed on by Dechert LLP, as special counsel to the Dealer Manager in connection with the Offer.

INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

        Ernst & Young LLP, 200 Clarendon Street, Boston, Massachusetts 02116, serves as the independent registered public accounting firm of the Fund and will annually render an opinion on the financial statements of the Fund.

FINANCIAL STATEMENTS

        The audited financial statements included in the annual report to the Fund's shareholders for the year ended December 31, 2016, together with the report of Ernst & Young, LLP thereon, are incorporated into the SAI by reference to the Fund's annual report to shareholders, filed with the SEC on Form N-CSR on February 21, 2017. The unaudited financial statements included in the semi-annual report to the Fund's shareholders for the six months ended June 30, 2017 are incorporated into the SAI by reference to the Fund's semi-annual report to shareholders, filed with the SEC on Form N-CSRS on August 10, 2017.

        All other portions of the annual and semi-reports to shareholders are not incorporated into the SAI by reference and are not part of the registration statement, the SAI, the Prospectus or this Prospectus Supplement.

ADDITIONAL INFORMATION

        This Prospectus Supplement and the accompanying Prospectus constitute part of a Registration Statement filed by the Fund with the SEC under the Securities Act and the Investment Company Act of 1940, as amended. This Prospectus Supplement and the accompanying Prospectus omit certain of the information contained in the Registration Statement, and reference is hereby made to the Registration Statement and related exhibits for further information with respect to the Fund and the Common Shares offered hereby. Any statements contained herein concerning the provisions of any document are

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not necessarily complete, and, in each instance, reference is made to the copy of such document filed as an exhibit to the Registration Statement or otherwise filed with the SEC. Each such statement is qualified in its entirety by such reference. The complete Registration Statement may be obtained from the SEC upon payment of the fee prescribed by its rules and regulations or free of charge through the SEC's web site (http://www.sec.gov).

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BASE PROSPECTUS dated August 2, 2017

$100,000,000

RMR Real Estate Income Fund

Common Shares
Preferred Shares
Subscription Rights to Purchase Common Shares
Subscription Rights to Purchase Preferred Shares
Subscription Rights to Purchase Common and Preferred Shares

            Investment Objective. RMR Real Estate Income Fund (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's primary investment objective is to earn and pay to its common shareholders a high level of current income by investing in real estate companies. Capital appreciation is the Fund's secondary objective. The Fund's investment adviser is RMR Advisors LLC. Under normal market conditions, the Fund invests: at least 90% of its managed assets (consisting of the net asset value of the Fund's common shares plus the liquidation preference of the Fund's preferred shares and the principal amount of the Fund's outstanding borrowings) in income producing securities issued by real estate companies, including common shares, preferred shares and debt; at least 75% of its managed assets in securities issued by real estate investment trusts ("REITs"); and no more than 10% of its managed assets in securities denominated in currencies other than the U.S. dollar or traded on a non-U.S. stock exchange. For the purposes of its investment policies, the Fund defines a "real estate company" as an entity that derives at least 50% of its revenues from the ownership, leasing, management, construction, sale or financing of commercial, industrial or residential real estate, or has at least 50% of its assets in real estate. The Fund may invest in securities rated in the lower rating categories of the established rating services (securities not rated Baa3, BBB- or BBB- or higher by at least one of Moody's Investors Service, Inc., Standard & Poor's, a division of the McGraw-Hill Companies, Inc., or Fitch Ratings, Inc., respectively), or securities that are unrated and considered non-investment grade quality by the Advisor. Securities which are not investment grade rated, or which are unrated and considered non-investment grade quality by the Advisor, are considered to have speculative characteristics with regard to their capacities to pay interest, distributions or principal according to stated terms. Debt securities that are not investment grade quality are sometimes referred to as "junk bonds"; debt and preferred securities that are not investment grade quality are also sometimes referred to as "high yield" securities. There can be no assurance that the Fund's investment objective will be achieved or that the Fund's investment program will be successful.

            As provided in the 1940 Act and subject to certain exceptions, the Fund may issue additional senior securities (which may be stock, such as preferred shares, and/or borrowings) only if immediately after such issuance the value of the Fund's total assets, less certain ordinary course liabilities, exceeds 300% of the amount of the borrowings outstanding and exceeds 200% of the amount of preferred shares and borrowings outstanding. The Fund currently uses leverage by issuing preferred shares or by borrowing from banks or other financial institutions. As of December 31, 2016, the Fund had issued auction rate preferred shares with an aggregate liquidation preference of $16,675,000, and had $60,000,000 in outstanding borrowings on a revolving credit facility with BNP Paribas Prime Brokerage International Limited. As of December 31, 2016, the amount of leverage represented approximately 28.2% of the Fund's managed assets. The Fund may revise the amount and type of leverage it employs at any time and from time to time without notice to shareholders based on market conditions or other factors considered relevant by the Fund's Board. The cost of using leverage will be borne by the Fund's common shareholders. Because the fee the Fund pays to the Advisor is calculated on the basis of the Fund's managed assets, the Fund's use of leverage increases the fee paid to the Advisor. There can be no assurance that the Fund's leverage strategies will be successful.

            The Fund is organized as a Maryland statutory trust. On April 18, 2017, the Fund was redomesticated as a Maryland statutory trust from a Delaware statutory trust. The Fund commenced its investment operations in December 2003 as "RMR Real Estate Fund." An investment in the Fund is not appropriate for all investors.

            We may offer, from time to time, in one or more offerings, our common and/or preferred shares, each with a par value $0.001 per share (together, "shares"), and/or our subscription rights to purchase our common and/or preferred shares, which we refer to collectively as the "securities." Securities may be offered at prices and on terms to be set forth in one or more supplements to this prospectus (this "Prospectus" and each supplement thereto, a "Prospectus Supplement"). You should read this Prospectus and the applicable Prospectus Supplements carefully before you invest in our securities.

            Annualized distributions on our common and preferred shares may contain a return of capital. Shareholders who receive the payment of a distribution consisting of a return of capital may be under the impression that they are receiving net profits when they are not. Shareholders should not assume that the source of a distribution from the Fund is net profit.

            Our securities may be offered directly to one or more purchasers, through agents designated from time to time by us, 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 our securities, and will set forth any applicable purchase price, fee, commission or discount arrangement between us and our agents or underwriters, or among our underwriters, or the basis upon which such amount may be calculated. The Prospectus Supplement relating to any sale of preferred shares will set forth the liquidation preference and information about the dividend period, dividend rate, any call protection or non-call period and other matters. The Prospectus Supplement relating to any offering of subscription rights will set forth the number of common and/or preferred shares issuable upon the exercise of each right and the other terms of such rights offering. We may offer subscription rights for common shares, preferred shares or common and preferred shares. We may not sell any of our securities through agents, underwriters or dealers without delivery of a Prospectus Supplement describing the method and terms of the particular offering of our securities.

            The Fund's common shares of beneficial interest (the "common shares") are listed on the NYSE American LLC under the symbol "RIF". On July 26, 2017 the last reported sale price of the common shares was $22.01. The net asset value of the Fund's common shares at the close of business on July 26, 2017 was $26.05 per share.

            Shares of closed-end funds often trade at a discount from net asset value. This creates a risk of loss for an investor purchasing shares in a public offering.

            Investing in the Fund's securities involves certain risks that are described in the "Risk Factors and Special Considerations" section beginning on page 53 of this Prospectus. Certain of these risks are summarized in "Prospectus Summary—Risk Factors and Special Considerations" beginning on page 10.

            Neither the U.S. Securities and Exchange Commission (the "SEC") nor any state securities commission has approved or disapproved of these securities or determined if this Prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

            This Prospectus may not be used to consummate sales of securities by us through agents, underwriters or dealers unless accompanied by a Prospectus Supplement.

            This Prospectus, together with an applicable Prospectus Supplement, sets forth concisely the information about the Fund that a prospective investor should know before investing. You should read this Prospectus, together with an applicable Prospectus Supplement, which contains important information about the Fund, before deciding whether to invest in the securities and retain it for future reference. A Statement of Additional Information, dated August 2, 2017 containing additional information about the Fund (the "SAI"), has been filed with the SEC and, as amended from time to time, is incorporated by reference in its entirety into this Prospectus. You can review the table of contents for the SAI on page 123 of this Prospectus. You may request a free copy of the SAI by calling (617) 332-9530 or by writing to the Fund, or obtain a copy (and other information regarding the Fund) from the SEC's Public Reference Room in Washington, D.C. Call (202) 551-8090 for information. The SEC charges a fee for copies. You can get the same information free from the SEC's website (http://www.sec.gov). You may also e-mail requests for these documents to publicinfo@sec.gov or make a request in writing to the SEC's Public Reference Section, 100 F Street N.E., Washington, D.C. 20549-0102. In addition, you may request copies of the Fund's semi-annual and annual reports or other information about the Fund or make shareholder inquiries by calling (617) 332-9530. The Fund's annual and semi-annual reports, when produced, will be available at the Fund's website http://www.rmrfunds.com free of charge. Information contained in, or that can be accessed through, the Fund's website is not part of this Prospectus.

            You should not construe the contents of this Prospectus as legal, tax or financial advice. You should consult with your own professional advisors as to the legal, tax, financial or other matters relevant to the suitability of an investment in the Fund.

            The Fund's securities do not represent a deposit or an 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.

            You should rely only on the information contained or incorporated by reference in this Prospectus and any applicable Prospectus Supplement. The Fund has not, and the underwriters have 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, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information in this Prospectus and any applicable Prospectus Supplement is accurate only as of the date of this Prospectus or the date of the applicable Prospectus Supplement. The Fund's business, financial condition and prospects may have changed since that date.

TABLE OF CONTENTS

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SUMMARY OF FUND EXPENSES

        The following table shows the Fund's expenses as a percentage of net assets attributable to common shares.

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Expense Example

        The following example illustrates the expenses (including the maximum estimated sales load of $37.50 on common shares, and estimated offering expenses of $6 from the issuance of $100 million in common shares) that you would pay on each $1,000 investment in our common shares, assuming (1) total net annual expenses of 2.66% in years 1 through 10, (2) a 5% annual return and (3) that all dividends and distributions are reinvested at net asset value.

        The purpose of this example is to assist you in understanding the various costs and expenses that you, as a common shareholder, will bear directly or indirectly.

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FINANCIAL HIGHLIGHTS

        The selected data below sets forth the per share operating performance and ratios for the periods presented. The financial information was derived from and should be read in conjunction with the Financial Statements of the Fund and Notes thereto, which are incorporated by reference into the Statement of Additional Information. The financial information for each of the fiscal years ended December 31, 2016, 2015, 2014, 2013 and 2012 has been audited by Ernst & Young LLP, the Fund's independent registered public accounting firm, whose unqualified report on such Financial Statements is included in the Fund's annual report to shareholders, filed with the SEC on Form N-CSR on February 21, 2017, for the fiscal year ended December 31, 2016, and which is available without charge by calling the Fund's toll free number: (617) 332-9530.

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        Selected data for a common share of beneficial interest outstanding throughout the period.