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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 3FheOUbBOMQjczK6hoEXgw==

<SEC-DOCUMENT>0001223373-09-000025.txt : 20090106
<SEC-HEADER>0001223373-09-000025.hdr.sgml : 20090106
<ACCEPTANCE-DATETIME>20090106142402
ACCESSION NUMBER:		0001223373-09-000025
CONFORMED SUBMISSION TYPE:	3/A
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20090101
FILED AS OF DATE:		20090106
DATE AS OF CHANGE:		20090106

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			FORD GOLDFARB MAUREEN R
		CENTRAL INDEX KEY:			0001223373

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-04992
		FILM NUMBER:		09509461

	MAIL ADDRESS:	
		STREET 1:		101 HUNTINGTON AVE
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02199

	FORMER NAME:	
		FORMER CONFORMED NAME:	FORD MAUREEN R
		DATE OF NAME CHANGE:	20030317

ISSUER:		

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

	BUSINESS ADDRESS:	
		STREET 1:		500 BOYLSTON ST
		STREET 2:		20TH FL LEGAL DEPT.
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		6179545000

	MAIL ADDRESS:	
		STREET 1:		500 BOYLSTON ST
		STREET 2:		20TH FL LEGAL DEPT
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COLONIAL MUNICIPAL INCOME TRUST
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>3/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2009-01-01</periodOfReport>

    <dateOfOriginalSubmission>2009-01-06</dateOfOriginalSubmission>

    <noSecuritiesOwned>1</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001223373</rptOwnerCik>
            <rptOwnerName>FORD GOLDFARB MAUREEN R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>18 ST. THOMAS DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PALM BEACH GARDENS</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33418</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <ownerSignature>
        <signatureName>Susan S. Newton, By Power of Attorney</signatureName>
        <signatureDate>2009-01-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99
<SEQUENCE>2
<FILENAME>poagoldfarb.txt
<DESCRIPTION>POWER OF ATTORNEY
<TEXT>
                               POWER OF ATTORNEY



The undersigned on his or her own behalf and on behalf of his or her estate,
heirs and assigns hereby constitutes and appoints Susan S. Newton, Christopher
R. Bohane, Timothy M. Fagan, Susan A. Pereira and Brian E. Langenfeld and each
of them singly as true and lawful attorneys with full power to them and each of
them, to execute, on behalf of the undersigned, in the capacity listed below,
any and all statements or reports under Section 16 of the Securities Exchange
Act of 1934, as amended, with respect to the beneficial ownership of reportable
securities issued by MFS California Insured Municipal Trust, MFS Charter Income
Trust, MFS Government Markets Income Trust, MFS High Income Municipal Trust, MFS
High Yield Municipal Trust, MFS InterMarket Income Trust I, MFS Intermediate
High Income Fund, MFS Intermediate Income Trust, MFS Investment Grade Municipal
Trust, MFS Multimarket Income Trust, MFS Municipal Income Trust and MFS Special
Value Trust including, without limitation, all initial statements of beneficial
ownership on Form 3, all statements of changes of beneficial ownership on Form 4
and all annual statements of beneficial ownership on Form 5, and any and all
other documents that may be required, from time to time, to be filed with the
Securities and Exchange Commission, to execute any and all amendments or
supplements to any such statements or forms, and to file the same, with all
exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, granting to said attorney, full power and
authority to do so and perform each and every act and thing requisite and
necessary to be done in and about the premises, as fully to all intents and
purposes as the undersigned (or his or her estate, heirs and assigns) might or
could do in person, hereby ratifying and confirming all that said attorneys or
any of them may lawfully do or cause to be done by virtue hereof.

     IN  WITNESS  WHEREOF,  the  undersigned  has  set  his or her  hand on this
________ day of ________________, 200_.



- -------------------------
Maureen R. Goldfarb


</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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