SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 9)

MFS High Yield Municipal Trust

(Name of Issuer)

Common Stock

(Title of Class of Securities)

59318E102

(CUSIP Number)

Phillip Goldstein
250 Pehle Ave., Suite 708
Saddle Brook, NJ, 07663
914 747-5262

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

12/12/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. Checkbox not checked

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No.

59318E102

Name of reporting person

Bulldog Investors, LLP

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 109,810.00
8	Shared Voting Power 3,561,726.00
9	Sole Dispositive Power 109,810.00
10	Shared Dispositive Power 3,561,726.00

Aggregate amount beneficially owned by each reporting person

3,671,536.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

14.4 %

Type of Reporting Person (See Instructions)

SCHEDULE 13D

CUSIP No.

59318E102

Name of reporting person

Phillip Goldstein

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 109,810.00
8	Shared Voting Power 3,898,111.00
9	Sole Dispositive Power 109,810.00
10	Shared Dispositive Power 3,898,111.00

Aggregate amount beneficially owned by each reporting person

4,007,921.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

15.72 %

Type of Reporting Person (See Instructions)

SCHEDULE 13D

CUSIP No.

59318E102

Name of reporting person

Andrew Dakos

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 3,561,726.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 3,561,726.00

Aggregate amount beneficially owned by each reporting person

3,561,726.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

13.97 %

Type of Reporting Person (See Instructions)

SCHEDULE 13D

Item 1.

Security and Issuer

(a)

Title of Class of Securities:

Common Stock

(b)

Name of Issuer:

MFS High Yield Municipal Trust

(c)

Address of Issuer's Principal Executive Offices:

111 Huntington Avenue, 24TH FLOOR, Boston, MASSACHUSETTS , 02199.

Item 1 Comment:

This Constitutes Amendment #9 to the schedule 13D filed July 17, 2023. Except as specifically set forth herein, the schedule 13D remains unmodified.

Item 5.

Interest in Securities of the Issuer

(a)

As per the N-CSRS filed on 7/28/25 there were 25,492,782 shares of common stock outstanding as of 5/31/25. The percentages set forth herein were derived using such number. Phillip Goldstein and Andrew Dakos own Bulldog Investors, LLP, a registered investment advisor. As of December 12, 2025, Bulldog Investors, LLP is deemed to be the beneficial owner of 3,671,536 shares of CMU (representing 14.40% of CMU's outstanding shares) solely by virtue of Bulldog Investors, LLP's power to direct the vote of, and dispose of, these shares. As of December 12, 2025, Mr. Goldstein is deemed to be the beneficial owner of 4,007,921 shares of CMU (representing 15.72% of CMU's outstanding shares) and Mr. Dakos is deemed to be the beneficial owner of 3,561,726 shares of CMU (representing 13.97% of CMU's outstanding shares) by virtue of their power to direct the vote of, and dispose of, these shares.

(b)

Bulldog Investors, LLP has sole power to dispose of and vote 109,810 shares. Bulldog Investors, LLP has shared power to dispose and vote 3,561,726 shares. Certain of Bulldog Investors, LLP's clients (none of whom beneficially own more than 5% of CMU's shares) share this power with Bulldog Investors. Messrs. Goldstein and Dakos are partners of Bulldog Investors, LLP.

(c)

Since the last filing on 11/14/25 the following shares of CMU were purchased. Date Shares Price 12/12/2025 215,000 3.4782 12/11/2025 20,000 3.4797 12/9/2025 20,000 3.4800 12/8/2025 20,000 3.4895 12/5/2025 12,806 3.4900 12/3/2025 14,015 3.4760 12/2/2025 18,500 3.4890 12/1/2025 20,000 3.4899 11/25/2025 20,000 3.5083 11/24/2025 3,735 3.4900

(d)

Clients of Bulldog Investors, LLP and the owners of accounts reflected herein are entitled to receive any dividends or sales proceeds.

(e)

N/A

Item 6.

Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer

None

Item 7.

Material to be Filed as Exhibits.

None

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Bulldog Investors, LLP

Signature:	/s/ Andrew Dakos
Name/Title:	Andrew Dakos, Partner
Date:	12/15/2025

Phillip Goldstein

Signature:	/s/ Phillip Goldstein
Name/Title:	Phillip Goldstein
Date:	12/15/2025

Andrew Dakos

Signature:	/s/ Andrew Dakos
Name/Title:	Andrew Dakos
Date:	12/15/2025

Amendment: SEC Form SCHEDULE 13D/A filed by MFS Municipal Income Trust