[Form 4] MFS High Yield Municipal Trust Insider Trading Activity

Rhea-AI Filing Summary

MFS High Yield Municipal Trust (NYSE:CMU) submitted a Form 4 reporting changes in insider ownership.

The disclosure identifies William Adams — an officer of the fund’s adviser — as the reporting person. The earliest transaction date is listed as 09/30/2024, and the Form was signed on 06/27/2025 and filed on 06/28/2025. The excerpt provided does not include the usual numeric detail (share amounts, prices or transaction codes), preventing assessment of the dollar value or relative size of the trade.

Because no quantitative data is shown, investors should review the full Form 4 on the SEC website to determine whether the transaction is material. Based on the limited information, the filing appears to be a routine Section 16 compliance event.

Insights

Corporate Governance Expert

TL;DR: Routine Form 4; no share counts disclosed, likely immaterial to CMU holders.

The purpose of this filing is strictly regulatory: William Adams, as an officer of the adviser, is updating the public record of his beneficial ownership. The absence of reported share quantities or prices in the excerpt suggests the transaction was modest, or those lines were omitted here. Without those metrics the market cannot gauge significance, but nothing in the narrative signals a strategic shift, governance concern, or liquidity event. I therefore classify the impact as neutral, pending review of the full document.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Adams William

(Last) (First) (Middle)

111 HUNTINGTON AVENUE

(Street)

BOSTON MA 02199

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MFS HIGH YIELD MUNICIPAL TRUST [ CMU ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			OFFICER OF ADVISOR

3. Date of Earliest Transaction (Month/Day/Year)
09/30/2024

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

	CHRISTOPHER R. BOHANE	06/27/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did CMU's William Adams report on the June 28 2025 Form 4?

The filing discloses that officer William Adams changed his beneficial ownership, with the earliest transaction dated 09/30/2024; share and price details are not shown in the excerpt.

When did the reported transaction by William Adams occur?

The Form 4 lists 09/30/2024 as the earliest transaction date.

What is William Adams’s relationship to MFS High Yield Municipal Trust?

He is identified as an Officer of the Adviser to the trust.

Is William Adams still subject to Section 16 reporting obligations?

Yes. The filing indicates he continues to file under Section 16, as no termination box was checked.