<SEC-DOCUMENT>0001700264-24-000034.txt : 20241001
<SEC-HEADER>0001700264-24-000034.hdr.sgml : 20241001
<ACCEPTANCE-DATETIME>20241001143339
ACCESSION NUMBER:		0001700264-24-000034
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20240331
FILED AS OF DATE:		20241001
DATE AS OF CHANGE:		20241001

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			YOST JAMES O
		CENTRAL INDEX KEY:			0001253368
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-04992
		FILM NUMBER:		241342649

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MFS HIGH YIELD MUNICIPAL TRUST
		CENTRAL INDEX KEY:			0000809844
		ORGANIZATION NAME:           	
		IRS NUMBER:				042950868
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1130

	BUSINESS ADDRESS:	
		STREET 1:		111 HUNTINGTON AVENUE
		STREET 2:		24TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02199
		BUSINESS PHONE:		617-954-5000

	MAIL ADDRESS:	
		STREET 1:		111 HUNTINGTON AVENUE
		STREET 2:		24TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02199

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COLONIAL MUNICIPAL INCOME TRUST
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-03-31</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000809844</issuerCik>
        <issuerName>MFS HIGH YIELD MUNICIPAL TRUST</issuerName>
        <issuerTradingSymbol>CMU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001253368</rptOwnerCik>
            <rptOwnerName>YOST JAMES O</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>MFS INVESTMENT MANAGEMENT</rptOwnerStreet1>
            <rptOwnerStreet2>111 HUNTINGTON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02199</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>TREASURER</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <ownerSignature>
        <signatureName>CHRISTOPHER R. BOHANE</signatureName>
        <signatureDate>2024-10-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
