<DOCUMENT>
<TYPE>DEFA14A
<SEQUENCE>1
<FILENAME>pcef081823defa14a.txt
<DESCRIPTION>DEFINITIVE ADDITIONAL MATERIALS
<TEXT>
                                 UNITED STATES
                        SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                             SCHEDULE 14A INFORMATION
                  Proxy Statement Pursuant to Section 14(a) of
                       the Securities Exchange Act of 1934


Filed by the Registrant  |X|

Filed by a Party other than the Registrant  | |

Check the appropriate box:

| |   Preliminary Proxy Statement

| |   Confidential, for Use of the Commission Only (as permitted by Rule
      14a-6(e)(2))

| |   Definitive Proxy Statement

|X|   Definitive Additional Materials

| |   Soliciting Material Pursuant to Rule 14a-12

                PIONEER DIVERSIFIED HIGH INCOME FUND, INC. (HNW)
                     PIONEER FLOATING RATE FUND, INC. (PHD)
                      PIONEER HIGH INCOME FUND, INC. (PHT)
                 PIONEER MUNICIPAL HIGH INCOME FUND, INC. (MHI)
            PIONEER MUNICIPAL HIGH INCOME ADVANTAGE FUND, INC. (MAV)
	  PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC. (MIO)
--------------------------------------------------------------------------------
                (Name of Registrant(s) as Specified In Its Charter)

                                     N/A
--------------------------------------------------------------------------------
    (Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

|X|   No fee required.

| |   Fee computed on table below per Exchange Act Rules 14a-6(i)(1) and 0-11.

      (1)  Title of each class of securities to which transaction applies:

           --------------------------------------------------------------------
      (2)  Aggregate number of securities to which transaction applies:

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      (3)  Per unit price or other underlying value of transaction computed
           pursuant to Exchange Act Rule 0-11 (set forth the amount on which
           the filing fee is calculated and state how it was determined):
           --------------------------------------------------------------------
      (4)  Proposed maximum aggregate value of transaction:

           --------------------------------------------------------------------
      (5)  Total fee paid:

         --------------------------------------------------------------------
| |   Fee paid previously with preliminary materials.

| |   Check box if any part of the fee is offset as provided by Exchange Act
      Rule 0-11 (a)(2) and identify the filing for which the offsetting fee was
      paid previously. Identify the previous filing by registration statement
      number, or the Form or Schedule and the date of its filing.

      (1)  Amount Previously Paid:

           --------------------------------------------------------------------
      (2)  Form, Schedule or Registration Statement No.:

           --------------------------------------------------------------------
      (3)  Filing Party:

           --------------------------------------------------------------------
      (4)  Date Filed:

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<PAGE>


                                     [LOGO]

                                                                August 18, 2023

                  PIONEER DIVERSIFIED HIGH INCOME FUND, INC.
                       PIONEER FLOATING RATE FUND, INC.
                        PIONEER HIGH INCOME FUND, INC.
                   PIONEER MUNICIPAL HIGH INCOME FUND, INC.
              PIONEER MUNICIPAL HIGH INCOME ADVANTAGE FUND, INC.
            PIONEER MUNICIPAL HIGH INCOME OPPORTUNITIES FUND, INC.

DEAR FELLOW STOCKHOLDER:

As an investor in one or more of the above Pioneer Closed-End Funds ("Funds"),
we have sent you proxy communications in connection with electing the Funds'
nominees to the Board of Directors at the Annual Meeting of Stockholders
scheduled to be held on September 12, 2023.

I am pleased to report that your fellow stockholders have responded and are
showing support for your Funds' nominees. However, your shares remain unvoted.
Please join your fellow investors by supporting the election of your highly
qualified and experienced nominees. Please take a few moments to sign, date and
mail the enclosed card in the prepaid envelope or follow the instructions below
to vote by telephone or internet.

                  [LOGO]  Vote by Phone by calling
                          1-833-406-5626 and speaking with a
                          proxy voting specialist today. Our
                          representatives are available
                          weekdays from 10 a.m. to 11 p.m.
                          Eastern time. You may also call the
                          toll-free number on the enclosed card
                          and follow the prompts.

                  [LOGO]  Vote by Internet by visiting the
                          internet address on the enclosed card
                          and following the instructions.

                  [LOGO]  Vote by Mail by completing, signing,
                          and dating the enclosed card and
                          returning it in the enclosed prepaid
                          return envelope.

Our proxy solicitor, Morrow Sodali Fund Solutions ("MSFS"), may call you to
answer any questions you may have regarding the proxy and to assist you in
voting. You can call MSFS at 1-833-406-5626 during normal business hours,
Monday - Friday, 10:00a.m. - 11:00p.m., Eastern if you have any questions
regarding the proxy.

Thank you in advance for your vote,

 [LOGO]

 LISA M. JONES
 PRESIDENT AND CHIEF EXECUTIVE OFFICER
 PIONEER FUNDS
                                                                  AAM_R2_0923
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