CMU MFS High Yield Municipal Trust

  The undersigned registered closed-end investment company hereby notifies the Securities and Exchange

  Commission that it intends to redeem securities of which it is the issuer, as set forth below in accordance

  with the requirements of Rule 23c-2 under the Investment Company Act of 1940, as amended. Such

  redemption remains subject to the issuance of a formal notice of redemption, which will contain the

  definitive terms and timetable of redemption.

1.	Title of the class of securities of MFS High Yield Municipal Trust (the "Fund") to be redeemed:

Remarketable Variable Rate MuniFund Term Preferred Shares, Series 2051 (CUSIP # 59318E607)

("RVMTP Shares").

2.	Date on which the securities are to be called or redeemed:

November 3, 2023

No notices of redemption have yet been distributed, and the redemptions may be effected on a later date,

or not at all, due to market conditions or otherwise.

3.	The applicable provisions of the governing instrument pursuant to which the securities are to be called or redeemed:

The RVMTP Shares are to be redeemed pursuant to Section 2.6(c) of the Fund's Statement Establishing and Fixing the Rights and Preferences of Remarketable Variable Rate MuniFund Term Preferred Shares.

4.	The principal amount or number of shares and the basis upon which the securities to be redeemed are to be selected:

The Fund intends to redeem up to 100 shares of the outstanding RVMTP Shares, of which there are

700 outstanding shares, but may redeem less.

---

Notice:

The Fund’s Agreement and Declaration of Trust is on file with the Secretary of The Commonwealth of Massachusetts. This instrument is executed on behalf of the Fund by an officer of the Fund, as an officer of the Fund, and not individually, and the obligations imposed upon the Fund by this instrument, if any, are not binding upon any of the Fund’s officers, trustees or shareholders individually, but are binding only upon the assets and properties of the Fund.