UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF

REGISTERED MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-4992

MFS HIGH YIELD MUNICIPAL TRUST

(Exact name of registrant as specified in charter)

500 Boylston Street, Boston, Massachusetts 02116

(Address of principal executive offices) (Zip code)

Susan S. Newton

Massachusetts Financial Services Company

500 Boylston Street

Boston, Massachusetts 02116

(Name and address of agents for service)

Registrant’s telephone number, including area code: (617) 954-5000

Date of fiscal year end: November 30

Date of reporting period: February 29, 2008

ITEM 1. SCHEDULE OF INVESTMENTS.

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08

Issuer	Shares/Par		Value ($)
Municipal Bonds – 164.2%
Airport & Port Revenue – 6.0%
Branson, MO, Regional Airport Transportation Development District Airport Rev., “B”, 6%, 2037	$	460,000	$	388,180
Dallas Fort Worth, TX, International Airport Rev. Improvement, “B”, FSA, 5%, 2025		3,000,000		2,779,560
New York, NY, City Industrial Development Authority Rev. (Terminal One Group Assn.), 5.5%, 2021		500,000		495,425
Port Authority NY & NJ, Cons Thirty Seventh, FSA, 5.125%, 2030 (f)		4,450,000		4,176,592
			$	7,839,757
General Obligations - General Purpose – 3.3%
New York, NY, “H”, IBC, “N”, MBIA, 5.125%, 2025	$	3,510,000	$	3,487,852
Puerto Rico Government Development Bank, “B”, 5%, 2015		400,000		411,340
State of California, 5.25%, 2023		380,000		379,981
			$	4,279,173
General Obligations - Schools – 0.5%
Irving, TX, Independent School District, “A”, 0%, 2016	$	1,000,000	$	703,290
Healthcare Revenue - Hospitals – 30.1%
Allegheny County, PA, Hospital Development Authority Rev. (West Penn Allegheny Health), “A”, 5%, 2028	$	435,000	$	359,997
Allegheny County, PA, Hospital Development Authority Rev. (West Penn Allegheny Health), “A”, 5.375%, 2040		625,000		513,550
Cass County, MO, Hospital Rev., 5.625%, 2038		185,000		167,525
Colorado Health Facilities Authority Rev. (National Jewish Medical & Research Center), 5.375%, 2016		1,500,000		1,503,105
Colorado Health Facilities Authority Rev. (Parkview Medical Center), 5%, 2025		550,000		496,589
Conway, AR, Hospital Rev. (Conway Regional Medical Center), “A”, 6.4%, 2029		350,000		352,093
Conway, AR, Hospital Rev. (Conway Regional Medical Center), “B”, 6.4%, 2029		850,000		855,083
Delaware County, PA, Authority Rev. (Mercy Health Corp.), ETM, 6%, 2016		1,400,000		1,425,900
Delaware County, PA, Authority Rev. (Mercy Health Corp.), ETM, 6%, 2026		500,000		507,680
Dickinson County, MI, Healthcare System Hospital Rev., 5.7%, 2018		770,000		759,667
Forsyth County, GA, Hospital Authority Rev. (Baptist Health Care System), ETM, 6%, 2008		170,000		173,551
Garden City, MI, Hospital Finance Authority Rev. (Garden City Hospital), 5%, 2038		500,000		369,770
Genesee County, NY, Industrial Development Agency Civic Facility Rev. (United Memorial Medical Center), 5%, 2027		90,000		74,575
Glendale, AZ, Industrial Development Authority (John C. Lincoln Health), 5%, 2042		140,000		115,457
Gwinnett County, GA, Hospital Authority Rev. (Gwinnett Hospital Systems), FSA, 8%, 2042		1,675,000		1,675,000
Highland County, OH, Joint Township, Hospital District Facilities Rev., 6.75%, 2009 (c)		670,000		723,432
Idaho Health Facilities Authority Rev. (IHC Hospitals, Inc.), ETM, 6.65%, 2021		2,750,000		3,224,897
Illinois Finance Authority Rev. (Kewanee Hospital), 5.1%, 2031		435,000		345,908
Illinois Health Facilities Authority Rev. (Swedish American Hospital), 6.875%, 2010 (c)		500,000		540,640
Indiana Health & Educational Facilities Authority, Hospital Rev. (Community Foundation of Northwest Indiana), 5.5%, 2037		1,125,000		971,190
Indiana Health Facilities Financing Authority Rev. (Community Foundation of Northwest Indiana ), “A”, 6%, 2034		425,000		396,495
Jefferson County, IA, Hospital Authority Rev. (Jefferson County Hospital), “C”, 5.8%, 2032		780,000		692,734
Knox County, TN, Health, Educational & Housing Facilities Board, Hospital Rev. (Covenant Health), “B-2”, FRN, 6.75%, 2046		550,000		550,000
Louisiana Public Facilities Authority Hospital Rev. (Lake Charles Memorial Hospital), 6.375%, 2034		830,000		778,565
Louisiana Public Facilities Authority Rev. (Touro Infirmary Project), “A”, 5.5%, 2019		250,000		241,552
Lufkin, TX, Health Facilities Development Corp. Rev. (Memorial Health System), 5.5%, 2032		60,000		54,378

1

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Healthcare Revenue - Hospitals – continued
Lufkin, TX, Health Facilities Development Corp. Rev. (Memorial Health System), 5.5%, 2037	$	60,000	$	53,717
Maryland Health & Higher Educational Facilites Authority Rev. (Washington County Hospital), 6%, 2043		120,000		111,596
Maryland Health & Higher Educational Facilities Authority Rev. ( Washington County Hospital), 5.75%, 2038		250,000		229,393
Maryland Health & Higher Educational Facilities Authority Rev. (Adventist Healthcare), “A”, 5%, 2016		365,000		365,522
Maryland Health & Higher Educational Facilities Authority Rev. (Adventist Healthcare), “A”, 5.75%, 2025		400,000		396,560
Massachusetts Development Finance Agency (Boston Biomedical Research), 5.65%, 2019		620,000		620,124
Massachusetts Health & Educational Facilities Authority Rev. (Civic Investments, Inc.), “A”, 9%, 2012 (c)		750,000		902,130
Massachusetts Health & Educational Facilities Authority Rev. (Jordan Hospital), “E”, 6.75%, 2033		250,000		253,797
Massachusetts Health & Educational Facilities Authority Rev. (Milford-Whitinsville Hospital), “C”, 5.25%, 2018		500,000		489,420
Massachusetts Health & Educational Facilities Authority Rev. (Milford-Whitinsville Hospital), “D”, 6.35%, 2012 (c)		250,000		280,075
Miami County, OH, Hospital Facilities Rev. (Upper Valley Medical Center), 5.25%, 2018		300,000		301,563
Minneapolis & St. Paul Redevelopment Authority Rev. (HealthPartners), 5.625%, 2022		200,000		200,514
Montgomery, AL, Medical Clinic Board Health Care Facility Rev. (Jackson Hospital & Clinic), 5.25%, 2031		125,000		109,171
Montgomery, AL, Medical Clinic Board Health Care Facility Rev. (Jackson Hospital & Clinic), 5.25%, 2036		620,000		531,266
New Hampshire Health & Educational Facilities Authority Rev. (Catholic Medical Center), “A”, 6.125%, 2012 (c)		175,000		195,073
New Hampshire Health & Educational Facilities Authority Rev. (Catholic Medical Center), “A”, 6.125%, 2032		25,000		25,134
New Hampshire Health & Educational Facilities Authority Rev. (Littleton Regional Hospital ), “A”, 6%, 2008 (c)		625,000		640,438
New Hampshire Health & Educational Facilities Authority Rev. (Littleton Regional Hospital ), “B”, 5.9%, 2008 (c)		675,000		691,949
New Hampshire Health & Educational Facilities Authority Rev. (Memorial Hospital at Conway), 5.25%, 2021		530,000		490,335
New Hampshire Higher Educational & Health Facilities Authority Rev. (Littleton Regional Hospital), “A”, 5.9%, 2008 (c)		500,000		512,275
New Jersey Health Care Facilities, Financing Authority Rev. (St. Peter’s University Hospital), 5.75%, 2037		545,000		505,013
New Mexico State Hospital Equipment Loan Council, Hospital Rev. (Rehoboth McKinley Christian Hospital), “A”, 5%, 2017		285,000		261,773
New York Dormitory Authority Rev. (NYU Hospital Center), “B”, 5.625%, 2037		300,000		275,658
New York Dormitory Authority Rev. (NYU Hospitals Center), “B”, 5.25%, 2024		240,000		225,257
Orange County, FL, Health Facilities Authority Rev. (Orlando Regional Healthcare), 5.75%, 2012 (c)		150,000		163,859
Philadelphia, PA, Hospitals & Higher Education Facilities Authority Rev. (Temple University Hospital), “A”, 5.5%, 2030		480,000		435,864
Salida, CO, Hospital District Rev., 5.25%, 2036		735,000		600,091
Saline County, MO, Industrial Development Authority Rev. (John Fitzgibbon Memorial Hospital, Inc.), 5.625%, 2035		985,000		865,323
Skagit County, WA, Public Hospital District No. 001, 5.75%, 2032		90,000		83,192
South Dakota Health & Educational Facilities Authority Rev. (Sioux Valley Hospitals & Health Systems), “A”, 5.25%, 2034		525,000		475,739

2

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Healthcare Revenue - Hospitals – continued
South Lake County, FL, Hospital District Rev. (South Lake Hospital, Inc.), 6.375%, 2034	$	250,000	$	250,970
Southwestern, IL, Development Authority Rev. (Anderson Hospital), 5.375%, 2015		500,000		502,710
Southwestern, IL, Development Authority Rev. (Anderson Hospital), 5.5%, 2020		550,000		537,878
Southwestern, IL, Development Authority Rev. (Anderson Hospital), 5.125%, 2026		500,000		445,940
St. Paul, MN, Housing & Redevelopment Authority Hospital Rev. (Healtheast), “A”, 5.7%, 2015		2,000,000		2,013,300
St. Paul, MN, Port Authority Lease Rev. (Regions Hospital), “1”, 5%, 2036		700,000		547,463
Sullivan County, TN, Health Educational & Housing Facilities Board Hospital Rev. (Wellmont Health Systems Project), “C”, 5.25%, 2036		490,000		437,183
Turlock, CA, Health Facilities Rev. (Emanuel Medical Center), 5.375%, 2034		1,000,000		877,930
Tyler, TX, Health Facilities Development Corp. (East Texas Medical Center), “A”, 5.25%, 2032		230,000		196,135
Tyler, TX, Health Facilities Development Corp. (East Texas Medical Center), “A”, 5.375%, 2037		190,000		162,471
Tyler, TX, Health Facilities Development Corp. (Mother Frances Hospital), 6%, 2012 (c)		750,000		825,825
West Contra Costa, CA, Healthcare District, AMBAC, 5.5%, 2029		105,000		92,749
West Orange, FL, Healthcare District, “A”, 5.65%, 2022		400,000		403,876
West Virginia Hospital Finance Authority Rev. (Charleston Medical Center), 6.75%, 2010 (c)		605,000		662,644
Wisconsin Health & Educational Facilities Authority Rev. (Aurora Health Care, Inc.), 6.4%, 2033		350,000		350,270
Wisconsin Health & Educational Facilities Authority Rev. (Fort Healthcare, Inc.), 6.1%, 2034		750,000		751,065
Wisconsin Health & Educational Facilities Authority Rev. (Wheaton Franciscan Healthcare), 5.75%, 2012 (c)		450,000		493,182
Wisconsin Health & Educational Facilities Authority Rev. (Wheaton Franciscan Services), 5.25%, 2034		935,000		768,645
			$	39,481,390
Healthcare Revenue - Long Term Care – 34.8%
Abilene, TX, Health Facilities Development Corp., Retirement Facilities Rev. (Sears Methodist Retirement), “A”, 5.9%, 2025	$	750,000	$	691,177
Abilene, TX, Health Facilities Development Corp., Retirement Facilities Rev. (Sears Methodist Retirement), “A”, 7%, 2033		200,000		201,136
Boston, MA, Industrial Development Financing Authority Rev. (Springhouse, Inc.), 5.875%, 2020		235,000		229,846
Bucks County, PA, Industrial Development Authority Retirement Community Rev. (Ann’s Choice, Inc.), “A”, 6.25%, 2035		250,000		229,952
Bucks County, PA, Industrial Development Authority Rev. (Lutheran Community Telford Center), 5.75%, 2027		90,000		79,866
Bucks County, PA, Industrial Development Authority Rev. (Lutheran Community Telford Center), 5.75%, 2037		120,000		102,553
Bucks County, PA, Industrial Development Authority, Retirement Community Rev. (Ann’s Choice, Inc.), 6.125%, 2025		500,000		468,325
California Statewide Communities Development Authority Rev. (Eskaton Properties, Inc.), 8.25%, 2010 (c)		700,000		798,483
Capital Projects Finance Authority, FL (Glenridge on Palmer Ranch), “A”, 8%, 2012 (c)		500,000		589,865
Carlton, MN, Health & Housing Facilities Rev. (Inter-Faith Social Services, Inc.), 7.5%, 2010 (c)		250,000		272,565
Chartiers Valley, PA, Industrial & Commercial Development Authority (Friendship Village), “A”, 5.75%, 2020		1,000,000		997,320
Chartiers Valley, PA, Industrial & Commercial Development Authority Rev. (Asbury Health Center), 6.375%, 2024		1,000,000		980,250

3

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Healthcare Revenue - Long Term Care – continued
Cole County, MO, Industrial Development Authority, Senior Living Facilities Rev. (Lutheran Senior Services), 5.5%, 2035	$	750,000	$	683,475
Colorado Health Facilities Authority Rev. (American Housing Foundation, Inc.), 8.5%, 2031		530,000		534,076
Colorado Health Facilities Authority Rev. (Christian Living Communities Project), “A”, 5.75%, 2037		500,000		428,955
Colorado Health Facilities Authority Rev. (Covenant Retirement Communities, Inc.), 5%, 2035		1,100,000		914,782
Colorado Health Facilities Authority Rev. (Volunteers of America Care Facilities), “A”, ETM, 5.45%, 2008		55,000		55,487
Columbus, GA, Housing Authority Rev. (Calvary Community, Inc.), 7%, 2019		450,000		414,553
Connecticut Development Authority Rev. (Elim Park Baptist Home, Inc.), 5.85%, 2033		430,000		410,190
Fulton County, GA, Residential Care Facilities (Canterbury Court), “A”, 6.125%, 2026		500,000		472,705
Fulton County, GA, Residential Care Facilities, First Mortgage (Lenbrook Square Foundation, Inc.), “A”, 5%, 2029		1,500,000		1,179,840
HFDC of Central Texas, Inc., Retirement Facilities Rev. (Legacy at Willow Bend), “A”, 5.75%, 2036		600,000		495,642
Houston, TX, Health Facilities Development Corp., (Buckingham Senior Living Community), “A”, 7%, 2014 (c)		500,000		586,070
Howard County, MD, Retirement Facilities Rev. (Vantage House Corp.), “A”, 5.25%, 2033		200,000		161,094
Huntington, NY, Housing Authority Rev. (Gurwin Senior Jewish Residences), “A”, 5.875%, 2019		420,000		398,080
Huntington, NY, Housing Authority Rev. (Gurwin Senior Jewish Residences), “A”, 6%, 2029		650,000		585,331
Illinois Finance Authority Rev. (Washington & Jane Smith Community), “A”, 6.25%, 2035		1,000,000		897,490
Illinois Health Facilities Authority Rev. (Lutheran Senior Ministries, Inc.), 7.375%, 2011 (c)		650,000		740,909
Illinois Health Facilities Authority Rev. (Washington & Jane Smith Community), “A”, 7%, 2032		525,000		526,633
Indiana Health Facilities Financing Authority Rev. (Hoosier Care, Inc.), 7.125%, 2034		1,020,000		966,195
Iowa Finance Authority, Health Care Facilities Rev. (Care Initiatives), 9.25%, 2011 (c)		950,000		1,139,078
Iowa Finance Authority, Health Care Facilities Rev. (Care Initiatives), “B”, 5.75%, 2018		550,000		533,313
Iowa Finance Authority, Health Care Facilities Rev. (Care Initiatives), “B”, 5.75%, 2028		1,475,000		1,313,015
James City County, VA, Economic Development (Virginia United Methodist Homes, Inc.), “A”, 5.4%, 2027		320,000		275,565
James City County, VA, Economic Development (Virginia United Methodist Homes, Inc.), “A”, 5.5%, 2037		520,000		432,817
Jefferson, GA, Development Authority Rev. (Senior Living Facilities), “A”, 5.875%, 2038		500,000		425,125
Johnson City, TN, Health & Educational Facilities Board (Appalachian Christian Village), “A”, 6.25%, 2032		250,000		229,440
Juneau, AK, City & Boro Non-recourse Rev. (St. Ann’s Care Project), 6.875%, 2025		925,000		867,789
Kent County, DE, Assisted Living (Heritage at Dover LLC), 7.625%, 2030		1,140,000		986,294
Kentucky Economic Development Finance Authority Health Facilities Rev. (AHF/Kentucky-IOWA, Inc.), 6.5%, 2029		395,000		431,186
Kentwood, MI, Economic Development Ltd. (Holland Home), “A”, 5.375%, 2036		750,000		638,257
La Verne, CA, COP (Brethren Hillcrest Homes), “B”, 6.625%, 2025		525,000		535,337
Lancaster, PA, Industrial Development Authority Rev. (Garden Spot Village), “A”, 7.625%, 2010 (c)		325,000		360,045
Lee County, FL, Industrial Development Authority Health Care Facilities Rev. (Shell Point Village), “A”, 5.5%, 2009 (c)		400,000		422,096
Manhattan, KS, Health Care Facilities Rev. (Meadowlark Hills Retirement Foundation), “A”, 6.375%, 2009 (c)		250,000		263,470

4

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PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Healthcare Revenue - Long Term Care – continued
Massachusetts Development Finance Agency Rev. (Adventcare), “A”, 6.75%, 2037	$	695,000	$	617,598
Massachusetts Development Finance Agency Rev. (Alliance Health of Brockton, Inc.), “A”, 7.1%, 2032		1,090,000		1,008,337
Massachusetts Development Finance Agency Rev. (Linden Ponds, Inc.), “A”, 5.5%, 2027		185,000		160,351
Massachusetts Development Finance Agency Rev. (Linden Ponds, Inc.), “A”, 5.75%, 2035		45,000		38,739
Massachusetts Development Finance Agency Rev. (Loomis Communities, Inc.), “A”, 5.625%, 2015		250,000		250,272
Massachusetts Development Finance Agency Rev. (Loomis Communities, Inc.), “A”, 6.9%, 2032		125,000		126,093
Massachusetts Industrial Finance Agency Rev. (GF/Massachusetts, Inc.), 8.3%, 2023		805,000		740,383
Meridian, MI, Economic Development Corp., First Mortgage (Burcham Hills Retirement Center), “A-1”, 5.25%, 2026		250,000		219,707
Metropolitan Government of Nashville & Davidson County, TN, Health & Educational Facilities Board Rev. (Blakeford at Green Hills), 5.65%, 2024		575,000		511,900
Montgomery County, PA, Industrial Development Authority Rev. (Whitemarsh Continuing Care), 6.125%, 2028		150,000		138,572
Montgomery County, PA, Industrial Development Authority Rev. (Whitemarsh Continuing Care), 6.25%, 2035		600,000		547,782
New Hampshire Higher Education & Health Facilities Authority Rev. (Rivermead at Peterborough Retirement Community), 5.75%, 2028		1,100,000		982,542
New Jersey Economic Development Authority Rev. (Lions Gate), “A”, 5.75%, 2025		400,000		361,956
New Jersey Economic Development Authority Rev. (Lions Gate), “A”, 5.875%, 2037		300,000		260,706
New Jersey Economic Development Authority Rev. (Seabrook Village, Inc.), 5.25%, 2026		500,000		429,975
New Jersey Economic Development Authority Rev. (Seabrook Village, Inc.), 5.25%, 2036		500,000		409,155
New Jersey Economic Development Authority Rev. (Seabrook Village, Inc.), “A”, 8.25%, 2010 (c)		700,000		797,328
New Jersey Economic Development Authority Rev. (Seashore Gardens), 5.375%, 2036		350,000		283,315
New Jersey Economic Development Authority Rev., First Mortgage (Winchester), “A”, 5.75%, 2024		500,000		474,305
North Carolina Medical Care Commission, First Mortgage (DePaul Community Facilities, Inc.), 7.625%, 2009 (c)		980,000		1,064,182
Roseville, MN, Elder Care Facilities (Care Institute, Inc.), 7.75%, 2023		1,630,000		1,369,510
Sartell, MN, Health Care & Housing Authority Rev. (The Foundation for Health Care), “A”, 6.625%, 2029		1,025,000		994,763
Savannah, GA, Economic Development Authority, First Mortgage (Marshes of Skidway), “A”, 7.4%, 2034		350,000		352,006
Shelby County, TN, Health, Educational & Housing Facilities Board Rev. (Germantown Village), “A”, 7.25%, 2034		300,000		281,211
South Carolina Jobs & Economic Development Authority Rev. (Woodlands at Furman), “A”, 6%, 2027		280,000		257,844
South Carolina Jobs & Economic Development Authority Rev. (Woodlands at Furman), “A”, 6%, 2042		260,000		227,750
South Carolina Jobs & Economic Development Authority, Health & Facilities Rev., First Mortgage (Wesley Commons), 5.125%, 2026		400,000		332,116
South Carolina Jobs & Economic Development Authority, Health Facilities Rev. (Wesley Commons), 5.3%, 2036		200,000		157,404
St. Johns County, FL, Industrial Development Authority (Glenmoor Project), “A”, 5.25%, 2026		500,000		425,175
Suffolk, VA, Industrial Development Authority, Retirement Facilities Rev. (Lake Prince Center, Inc.), 5.3%, 2031		250,000		211,208

5

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PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Healthcare Revenue - Long Term Care – continued
Tarrant County, TX, Cultural Education Facilities Finance Corp. (Edgemere Project), “A”, 6%, 2036	$	500,000	$	451,955
Washington County, MN, Housing & Redevelopment Authority Rev. (Aspen Cottages), 9.25%, 2022		905,000		861,460
Westminster, MD, Economic Development Rev. (Carroll Lutheran Village), “A”, 6.25%, 2034		500,000		467,115
Westmoreland County, PA, Industrial Development Authority Rev. (Redstone Retirement Community), “A”, 5.875%, 2032		600,000		522,846
Westmoreland County, PA, Industrial Development Retirement Authority Rev. (Redstone Retirement Community), “A”, 5.75%, 2026		1,250,000		1,120,213
Wisconsin Health & Educational Facilities Authority Rev. (AE Nursing), “A”, 8.5%, 2033		600,000		601,518
Wisconsin Health & Educational Facilities Authority Rev. (Attic Angel Community, Inc.), 5.75%, 2008 (c)		875,000		912,091
Wisconsin Health & Educational Facilities Authority Rev. (Clement Manor, Inc.), 5.75%, 2024		1,000,000		932,510
Wisconsin Health & Educational Facilities Authority Rev. (United Lutheran Home), 5.7%, 2028		750,000		679,500
Wisconsin Health & Educational Facilities Board Rev. (All Saints Assisted Living Project), 5.9%, 2027		90,000		81,662
Wisconsin Health & Educational Facilities Board Rev. (All Saints Assisted Living Project), 6%, 2037		185,000		163,893
			$	45,772,620
Healthcare Revenue - Other – 0.6%
Wisconsin Health & Educational Facilities Authority Rev. (Blood Center Southeastern Project), 5.75%, 2034	$	750,000	$	743,903
Industrial Revenue - Airlines – 5.2%
Alliance Airport Authority, TX (American Airlines, Inc.), 5.25%, 2029	$	1,330,000	$	963,239
Charlotte, NC, Douglas International Airport Special Facilities Rev. (U.S. Airways, Inc.), 5.6%, 2027		250,000		214,620
Charlotte, NC, Douglas International Airport Special Facilities Rev. (U.S. Airways, Inc.), 7.75%, 2028		500,000		509,655
Chicago, IL, O’Hare International Airport Special Facilities Rev. (American Airlines, Inc.), 5.5%, 2030		1,745,000		1,352,584
Cleveland, OH, Airport Special Rev. (Continental Airlines, Inc.), 5.7%, 2019		875,000		773,325
Dallas-Fort Worth, TX, International Airport Facilities Improvement Corp. Rev. (American Airlines, Inc.), 9%, 2029 (a)		750,000		803,595
New Jersey Economic Development Authority, Special Facilities Rev. (Continental Airlines, Inc.), 9%, 2033 (a)		1,250,000		1,363,700
New York, NY, City Industrial Development Agencies Rev. (American Airlines, Inc.), 7.625%, 2025		365,000		377,538
New York, NY, City Industrial Development Agency Special Facility Rev. (American Airlines, Inc.), “B”, 8.5%, 2028		500,000		530,680
			$	6,888,936
Industrial Revenue - Chemicals – 0.3%
Brazos River, TX, Harbor Navigation District (Dow Chemical Co.), “B-2”, 4.95%, 2033	$	400,000	$	345,284
Industrial Revenue - Environmental Services – 0.8%
Carbon County, UT, Solid Waste Disposal Rev. (Allied Waste Industries), “A”, 7.5%, 2010	$	250,000	$	251,582
Carbon County, UT, Solid Waste Disposal Rev. (Laidlaw Environmental), “A”, 7.45%, 2017		500,000		497,245

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PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Industrial Revenue - Environmental Services – continued
Gulf Coast Waste Disposal Authority, TX (Waste Management of Texas), “A”, 5.2%, 2028	$	360,000	$	305,298
			$	1,054,125
Industrial Revenue - Metals – 0.4%
Director of Nevada Department of Business & Industry (Wheeling/Pittsburgh Steel), “A”, 8%, 2014	$	170,000	$	172,305
Greensville County, VA, Industrial Development Authority Rev. (Wheeling/Pittsburgh Steel), “A”, 7%, 2014		435,000		422,455
			$	594,760
Industrial Revenue - Other – 4.5%
Annawan, IL, Tax Increment Rev. (Patriot Renewable Fuels LLC), 5.625%, 2018	$	350,000	$	322,021
Cartersville, GA, Development Authority Waste & Water Facilities Rev. (Anheuser- Busch Project), 5.95%, 2032		1,000,000		1,002,350
Gulf Coast, TX, Industrial Development Authority Rev. (CITGO Petroleum Corp.), 8%, 2028		375,000		394,406
Houston, TX, Industrial Development Corp. (United Parcel Service, Inc.), 6%, 2023		475,000		455,530
Indianapolis, IN, Airport Authority Rev., Special Facilities (FedEx Corp.), 5.1%, 2017		500,000		490,545
Michigan Strategic Fund Rev. (Michigan Sugar Co.), “A”, 6.25%, 2015		1,000,000		1,005,710
New Jersey Economic Development Authority Rev. (GMT Realty LLC), “B”, 6.875%, 2037		1,000,000		970,030
Virgin Islands Government Refinery Facilities Rev. (Hovensa Coker Project), 6.5%, 2021		250,000		253,680
Virgin Islands Public Finance Authority, Refinery Facilities Rev. (Hovensa Coker Project), 5.875%, 2022		400,000		385,900
Will-Kankakee, IL, Regional Development Authority Rev. (Flanders Corp.), 6.5%, 2017		655,000		641,959
			$	5,922,131
Industrial Revenue - Paper – 3.0%
Beauregard Parish, LA (Boise Cascade Corp.), 6.8%, 2027	$	1,000,000	$	1,001,740
Bedford County, VA, Industrial Development Authority Rev. (Nekooska Packaging Corp.), 5.6%, 2025		400,000		331,180
Camden, AL, Industrial Development Board Exempt Facilities Rev., “B” (Weyerhaeuser Co.), 6.375%, 2024		400,000		411,440
Courtland AL, Industrial Development Board Solid Waste Disposal Rev. (Champion International Corp.), 6%, 2029		1,000,000		1,009,720
Escambia County, FL, Environmental Improvement Rev. (International Paper Co.), “A”, 4.75%, 2030		290,000		221,380
Lowndes County, MS, Solid Waste Disposal & Pollution Control Rev. (Weyerhaeuser Co.), “B”, 6.7%, 2022		595,000		622,626
Phenix City, AL, Industrial Development Board Environmental Improvement Rev., “A” (MeadWestvaco Coated), 6.35%, 2035		400,000		403,312
			$	4,001,398
Miscellaneous Revenue - Entertainment & Tourism – 2.8%
Agua Caliente Band of Cahuilla Indians, CA, 5.6%, 2013 (z)	$	775,000	$	790,221
Cabazon Band Mission Indians, CA, 8.375%, 2015 (z)		170,000		175,239
Cabazon Band Mission Indians, CA, 8.75%, 2019 (z)		720,000		743,940
Cow Creek Band Umpqua Tribe of Indians, OR, “C”, 5.625%, 2026 (n)		650,000		578,233
Mashantucket Western Pequot Tribe, CT, “B”, 0%, 2018 (n)		1,100,000		588,093
Mohegan Tribe Indians, CT, Gaming Authority Rev., 6.25%, 2031 (n)		200,000		189,528
New York Liberty Development Corp. Rev. (National Sports Museum), “A”, 6.125%, 2019		400,000		392,404
Seminole Tribe, FL, Special Obligation, “A”, 5.25%, 2027 (n)		280,000		246,893
			$	3,704,551

7

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PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Miscellaneous Revenue - Other – 1.8%
Capital Trust Agency, FL (Aero Syracuse LLC), 6.75%, 2032	$	350,000	$	352,229
Los Angeles, CA, Regional Airports Improvement Corp. (LAX Fuel Corp.), AMBAC, 5.25%, 2023		500,000		443,315
Maryland Economic Development Corp. (Chesapeake Bay), “A”, 5%, 2031		750,000		607,027
Philadelphia, PA, Industrial Development Airport Rev. (Aero Philadelphia LLC), 5.25%, 2009		95,000		95,038
Summit County, OH, Port Authority Building Rev. (Twinsburg Township), “D”, 5.125%, 2025		655,000		565,999
V Lakes Utility District Ranking Water Systems Rev., 7%, 2037		300,000		268,053
			$	2,331,661
Multi-Family Housing Revenue – 10.5%
Broward County, FL, Housing Finance Authority Rev. (Chaves Lakes Apartments Ltd.), “A”, 7.5%, 2040	$	500,000	$	506,150
Capital Trust Agency, FL, Housing Authority Rev. (Atlantic Housing Foundation), “C”, 5.875%, 2028		660,000		599,993
Charter Mac Equity Issuer Trust, FHLMC, 6%, 2019 (n)		1,000,000		1,055,710
Charter Mac Equity Issuer Trust, “B”, FHLMC, 7.6%, 2010 (a)(n)		500,000		545,490
Clay County, FL, Housing Finance Authority Rev. (Madison Commons Apartments), “A”, 7.45%, 2040		495,000		497,816
District of Columbia Housing Finance Agency (Henson Ridge), 5.1%, 2037		655,000		583,710
Durham, NC, Durham Housing Authority Rev. (Magnolia Pointe Apartments), 5.65%, 2038 (a)		1,000,000		901,620
El Paso County, TX, Housing Finance Corp. (American Housing Foundation), “D”, 10%, 2032		295,000		295,021
El Paso County, TX, Housing Finance Corp. (American Housing Foundation, Inc.), “C”, 8%, 2032		290,000		290,055
GMAC Municipal Mortgage Trust, “B-1”, 5.6%, 2039 (a)(n)		500,000		467,135
Massachusetts Housing Finance Agency Rev., “B”, 5%, 2030		500,000		456,255
Massachusetts Housing Finance Agency Rev., “E”, 5%, 2028		500,000		452,715
Mississippi Home Corp., Rev. (Kirkwood Apartments), 6.8%, 2037		605,000		557,961
MuniMae TE Bond Subsidiary LLC, 5.8%, 2049 (n)		1,000,000		990,000
New Mexico Mortgage Finance Authority, Multi-Family Housing Rev. (Sun Pointe Apartments), “E”, FHA, 4.8%, 2040		500,000		422,465
New York, NY, City Housing Development Corp., “F-1”, 4.65%, 2025		750,000		673,140
North Carolina Medical Care Commission, Health Care Facilities Rev., “A”, (ARC Projects), 5.8%, 2034		800,000		792,576
Resolution Trust Corp., Pass-Through Certificates, “1993”, 8.5%, 2016 (z)		455,481		448,795
Seattle, WA, Housing Authority Rev., Capped Fund Program (High Rise Rehab), “I”, FSA, 5%, 2025		500,000		456,375
White Bear Lake, MN, Multi-Family Housing Rev. (Birch Lake), “A”, 10.25%, 2019		1,770,000		1,752,300
White Bear Lake, MN, Multi-Family Housing Rev. (Birch Lake), “B”, 0%, 2019		617,000		302,330
Wilmington, DE, Multi-Family Housing Rev. (Electra Arms Senior Associates), 6.25%, 2028		870,000		765,739
			$	13,813,351
Sales & Excise Tax Revenue – 7.8%
Bolingbrook, IL, Sales Tax Rev., 0% to 2008, 6.25% to 2024	$	500,000	$	496,970
Metropolitan Pier & Exposition Authority, State Tax Rev., MBIA, 0%, 2013		5,000,000		3,881,700
Metropolitan Pier & Exposition Authority, State Tax Rev., FGIC, 0%, 2014		3,990,000		3,002,714
Metropolitan Pier & Exposition Authority, State Tax Rev., MBIA, 0%, 2015		3,000,000		2,128,770
Metropolitan Pier & Exposition Authority, State Tax Rev., ETM, FGIC, 0%, 2014		1,010,000		783,800
			$	10,293,954
Single Family Housing - Local – 1.2%
Minneapolis & St. Paul Housing Authority Rev. (City Living), “A-2”, GNMA, 5%, 2038	$	739,193	$	648,893

8

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Single Family Housing - Local – continued
Pittsburgh, PA, Urban Redevelopment Authority Rev., “C”, GNMA, 4.8%, 2028	$	1,000,000	$	898,390
			$	1,547,283
Single Family Housing - State – 0.4%
Kentucky Counties Single Family Mortgage Rev., “A”, MBIA, 9%, 2016	$	5,000	$	5,010
North Dakota Housing Finance Agency Rev., “A”, 4.85%, 2021		500,000		460,410
			$	465,420
Solid Waste Revenue – 0.8%
Delaware County, PA, Industrial Development Authority, Resource Recovery Facilities Rev. (American Ref-Fuel Co.), “A”, 6.2%, 2019	$	1,000,000	$	997,480
State & Agency - Other – 0.4%
Commonwealth of Puerto Rico (Mepsi Campus), “A”, 6.25%, 2024	$	100,000	$	95,339
Commonwealth of Puerto Rico (Mepsi Campus), “A”, 6.5%, 2037		500,000		467,155
			$	562,494
State & Local Agencies – 2.6%
Dorchester County, SC, School District No. 2, Growth Remedy Opportunity Tax Hike, 5.25%, 2029	$	500,000	$	456,150
Laurens County, SC, School District No. 55, Installment Purchase Rev., 5.25%, 2030		700,000		603,554
Michigan Building Authority Rev., Facilities Program, “I”, 5%, 2024		1,000,000		988,830
Newberry, SC, Investing in Children’s Education (Newberry County School District Program), 5%, 2030		400,000		331,764
Puerto Rico Public Finance Corp., “E”, ETM, 6%, 2026		80,000		87,919
Puerto Rico Public Finance Corp., Unrefunded, “E”, 6%, 2026		820,000		901,172
			$	3,369,389
Tax - Other – 1.0%
Dallas County, TX, Flood Control District, 7.25%, 2032	$	750,000	$	729,187
New Jersey Economic Development Authority Rev. (Cigarette Tax), 5.75%, 2029		500,000		466,775
New Jersey Economic Development Authority Rev. (Cigarette Tax), 5.5%, 2031		120,000		107,872
			$	1,303,834
Tax Assessment – 15.1%
Atlanta, GA, Tax Allocation (Eastside Project), “B”, 5.4%, 2020	$	500,000	$	457,370
Ave Maria, FL, Stewardship Community, “A”, 5.125%, 2038		150,000		109,726
Celebration Community Development District, FL, “A”, 6.4%, 2034		720,000		734,940
Channing Park Community Development District, FL, 5.3%, 2038		400,000		298,372
Chicago, IL, Tax Increment Allocation (Pilsen Redevelopment), “B”, 6.75%, 2022		310,000		316,265
Colonial Country Club Community Development District, FL, 6.4%, 2033		480,000		489,960
Double Branch Community Development District, FL, “A”, 6.7%, 2034		485,000		494,472
Du Page County, IL, Special Service Area No. 31 Special Tax (Monarch Landing Project), 5.625%, 2036		250,000		206,995
Durbin Crossing Community Development District, FL, Special Assessment Rev., “B- 1”, 4.875%, 2010		250,000		235,292
Grand Bay at Doral Community Development, FL, “A”, 6%, 2039		90,000		74,732
Grand Bay at Doral Community Development, FL, “B”, 6%, 2017		545,000		496,190
Heritage Harbour North Community Development District, FL, Capital Improvement Rev., 6.375%, 2038		325,000		285,327
Homestead 50 Community Development District, FL, “A”, 6%, 2037		380,000		315,924
Homestead 50 Community Development District, FL, “B”, 5.9%, 2013		170,000		159,768
Huntington Beach, CA, Community Facilities District, Special Tax (Grand Coast Resort), “2000-1”, 6.45%, 2031		500,000		502,740
Islands at Doral Southwest Community Development District, FL, 6.375%, 2013 (c)		245,000		273,829
Lexington Oaks Community Development District, FL, “A”, 6.125%, 2019		650,000		650,052
Lincoln, CA, Special Tax (Community Facilities District ), “2003-1”, 5.55%, 2013 (c)		440,000		486,829
Lincolnshire, IL, Special Service Area No. 1 (Sedgebrook Project), 6.25%, 2034		250,000		228,697

9

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Tax Assessment – continued
Magnolia Park Community Development District, FL, Special Assessment Rev., “A”, 6.15%, 2039	$	680,000	$	579,884
Main Street Community Development District, “B”, 6.9%, 2017		225,000		221,092
Main Street Community Development District, FL, “A”, 6.8%, 2038		295,000		286,153
Northwest Metropolitan District No. 3, CO, 6.25%, 2035		500,000		413,920
Oakdale, CA, Public Financing Authority Tax Allocation Rev. (Central City Redevelopment Project), 5.375%, 2033		1,125,000		976,759
Oakmont Grove Community Development District, CA, “A”, 5.4%, 2038		300,000		221,178
Ohio County, WV, Commission Tax Increment Rev. (Fort Henry Centre), “A”, 5.85%, 2034		125,000		110,820
Orange County, CA, Community Facilities Tax No 99, (Ladera Ranch), “A”, 6.5%, 2009 (c)		1,000,000		1,075,080
Orange County, CA, Improvement Act 1915, “B”, 5.75%, 2033		500,000		450,005
Orlando, FL, Special Assessment Rev. (Conroy Road Interchange Project), “A”, 5.5%, 2010		65,000		63,731
Orlando, FL, Special Assessment Rev. (Conroy Road Interchange Project), “A”, 5.8%, 2026		300,000		277,176
Plano, IL, Special Service Area No. 4 (Lakewood Springs Project Unit 5-B), 6%, 2035		1,500,000		1,349,145
Pontiac, MI, Tax Increment Finance Authority Rev., 6.375%, 2012 (c)		450,000		506,876
Portage, IN, Economic Development Rev. (Ameriplex Project), 5%, 2027		260,000		234,112
Redwood City, CA, Special Tax Community Facilities, (District 1 Redwood), “B”, 6%, 2033		300,000		277,215
San Diego, CA, Redevelopment Agency, Tax Allocation, FSA, 0%, 2018		1,015,000		612,126
Sarasota National Community Development District, FL, Special Assessment Rev., 5.3%, 2039		800,000		586,680
Seven Oaks, FL, Community Development District II Special Assessment Rev., “B”, 5%, 2009		590,000		575,704
Stoneybrook, FL, Community Development District, “A”, 6.1%, 2019		215,000		215,097
Sweetwater Creek Community Development District, FL, Capital Improvement Rev., 5.5%, 2038		200,000		149,242
Temecula Valley, CA, Unified School District, Community Facilities District No. 02-1, 6.125%, 2033		355,000		338,315
Tolomato Community Development District, FL, Special Assessment Rev., 6.65%, 2040		585,000		537,358
Tuscany Reserve Community Development District, FL, Special Assessment Rev., “B”, 5.25%, 2016		185,000		157,903
Volo Village, IL, Special Service Area No. 3, Special Tax (Symphony Meadows Project), “1”, 6%, 2036		484,000		415,495
West Villages Improvement District, FL, Special Assessment Rev. (Unit of Development No. 3), 5.5%, 2037		500,000		388,950
Westchester, FL, Community Development District No. 1 (Community Infrastructure), 6.125%, 2035		275,000		232,488
Westridge, FL, Community Development District, Capital Improvement Rev., 5.8%, 2037		1,000,000		810,670
Wyandotte County-Kansas City, KS, Unified Government Transportation Development District (Legends Village West Project), 4.875%, 2028		585,000		479,443
Yorba Linda, CA, Redevelopment Agency, Tax Allocation Rev., “A”, MBIA, 0%, 2024		1,325,000		503,911
			$	19,864,008
Tobacco – 8.8%
Buckeye, OH, Tobacco Settlement Rev., Asset Backed, “A-2”, 5.875%, 2030	$	1,610,000	$	1,510,083
Buckeye, OH, Tobacco Settlement Rev., Asset Backed, “A-2”, 5.875%, 2047		495,000		449,306
Buckeye, OH, Tobacco Settlement Rev., Asset Backed, “A-2”, 6.5%, 2047		1,300,000		1,298,206
California County, CA, Tobacco Securitization Agency, Tobacco Settlement Rev. (Los Angeles County), 0%, 2046		3,500,000		189,735

10

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Tobacco – continued
Golden State, CA, Tobacco Securitization Corp., Tobacco Settlement Rev., “A-1”, 6.25%, 2013 (c)	$	1,600,000	$	1,748,320
Golden State, CA, Tobacco Securitization Corp., Tobacco Settlement Rev., “A-1”, 5.75%, 2047		1,000,000		897,610
Golden State, CA, Tobacco Securitization Corp., Tobacco Settlement Rev., Asset Backed, “A-1”, 5.125%, 2047		1,135,000		922,335
Inland Empire, CA, Tobacco Securitization Corp., Tobacco Settlement Rev., Asset Backed, “C-1”, 0%, 2036		1,815,000		241,613
Michigan Tobacco Settlement Finance Authority, Tobacco Settlement Rev., Asset Backed, “A”, 6%, 2048		1,710,000		1,588,436
Tobacco Securitization Authority of Southern California Rev., Asset Backed (San Diego Country Tobacco Asset Securitization Corp.), 0%, 2046		6,000,000		389,640
Tobacco Settlement Authority of Washington Rev., Asset Backed, 6.625%, 2032		500,000		503,150
Tobacco Settlement Financing Corp., NJ, 6.75%, 2013 (c)		1,000,000		1,151,680
Virginia Tobacco Settlement Financing Corp., “B-1”, 5%, 2047		830,000		655,808
			$	11,545,922
Toll Roads – 4.8%
E-470 Public Highway Authority, CO, “B”, 0%, 2010 (c)	$	8,750,000	$	1,223,950
E-470 Public Highway Authority, CO, “B”, MBIA, 0%, 2018		3,000,000		1,722,570
Northwest Parkway, CO, Public Highway Authority (First Tier), “D”, 7.125%, 2011 (c)		1,000,000		1,128,450
San Joaquin Hills, CA, Transportation Corridor Agency Toll Road Rev., “A”, MBIA, 0%, 2015		3,000,000		2,169,540
			$	6,244,510
Universities - Colleges – 1.5%
Maryland Health & Higher Educational Facilities Authority Rev. (Loyola College), “A”, 5.125%, 2045	$	500,000	$	456,360
Pennsylvania Higher Educational Facilities Authority Rev. (University of Philadelphia), “A”, 5.125%, 2025		570,000		504,849
Southfield, MI, Economic Development Corp. (Lawrence Technological University), “A”, 5.4%, 2018		750,000		707,625
West Virginia University Rev. (West Virginia University Project), “A”, AMBAC, 0%, 2025		750,000		268,875
			$	1,937,709
Universities - Dormitories – 0.8%
California Statewide Communities Development Authority Rev. (Lancer Educational Student Housing Project), 5.625%, 2033	$	735,000	$	644,815
Minneapolis, MN, Student Housing Rev. (Riverton Community Housing Project), “A”, 5.7%, 2040		500,000		433,570
			$	1,078,385
Universities - Secondary Schools – 1.4%
California Statewide Communities Development Authority Rev., COP, (Crossroads Schools for the Arts & Sciences), 6%, 2028	$	1,035,000	$	1,057,894
Colorado Housing Finance Development Rev. (Evergreen Country Day School), 5.875%, 2037		425,000		377,765
Lee County, FL, Industrial Development Authority Rev. (Lee Charter Foundation), “A”, 5.375%, 2037		535,000		429,541
			$	1,865,200
Utilities - Cogeneration – 2.5%
Port Authority NY & NJ, Special Obligation Rev., 6.75%, 2011	$	2,000,000	$	2,016,260
Puerto Rico Industrial, Tourist, Educational, Medical & Environmental Central Facilities (Cogeneration Facilities - AES Puerto Rico Project), 6.625%, 2026		320,000		332,614
Suffolk County, NY, Industrial Development Agency Rev. (Nissequoque Cogeneration Partners Facilities), 5.5%, 2023		550,000		492,811

11

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Utilities - Cogeneration – continued
Western Generation Agency, OR, Cogeneration Project Rev. (Wauna Cogeneration Project), “B”, 5%, 2016	$	500,000	$	474,510
			$	3,316,195
Utilities - Investor Owned – 5.6%
Brazos River Authority, TX, Pollution Control Rev. (TXU Electric Co. LLC), “C”, 5.75%, 2036 (a)	$	220,000	$	208,397
Brazos River Authority, TX, Pollution Control Rev. (TXU Electric Co. LLC), “C”, 6.75%, 2038		555,000		496,836
Brazos River Authority, TX, Pollution Control Rev. (TXU Electric Co. LLC), “D”, 5.4%, 2029 (a)		45,000		40,727
Bryant, IL, Pollution Control Rev. (Central Illinois Light Co.), 5.9%, 2023		1,000,000		1,002,570
Campbell County, WY, Pollution Control Rev. (Black Hills Power, Inc. Project), 5.35%, 2024		1,000,000		939,310
Clark County, NV, Industrial Development Rev. (Nevada Power Co. Project), “A”, 5.9%, 2032		1,500,000		1,299,480
Mississippi Business Finance Corp., Pollution Control Rev. (Systems Energy Resources Project), 5.875%, 2022		1,500,000		1,505,070
New Hampshire Business Finance Authority, Pollution Control Rev. (Public Service of New Hampshire), “B”, MBIA, 4.75%, 2021		250,000		238,228
Pennsylvania Economic Development Financing Authority Rev. (Reliant Energy Seward), “A”, 6.75%, 2036		400,000		397,932
Red River, TX, Authority Pollution Control, (AEP Texas Central Co.), MBIA, 4.45%, 2020		445,000		406,312
Sabine River Authority, TX, Pollution Control Rev. (TXU Electric Co. LLC), 5.2%, 2028		185,000		140,015
Sabine River Authority, TX, Pollution Control Rev. (TXU Electric Co. LLC), 5.75%, 2030 (a)		155,000		146,825
West Feliciana Parish, LA, Pollution Control Rev. (Entergy Gulf States), 6.6%, 2028		500,000		491,190
			$	7,312,892
Utilities - Municipal Owned – 0.3%
North Carolina Eastern Municipal Power Agency System Rev., “F”, 5.5%, 2016	$	430,000	$	444,285
Utilities - Other – 0.7%
Main Street Natural Gas, Inc., GA, “A”, 5.5%, 2028	$	335,000	$	280,452
Salt Verde Financial Corp., AZ, Senior Gas Rev., 5%, 2037		845,000		682,329
			$	962,781
Water & Sewer Utility Revenue – 3.9%
Houston, TX, Water & Sewer Systems Rev., “C”, AMBAC, 0%, 2012	$	3,000,000	$	2,492,400
Massachusetts Water Resources Authority, “D”, MBIA, 5%, 2024		2,000,000		2,003,940
Surprise, AZ, Municipal Property Corp., 4.9%, 2032		700,000		572,293
			$	5,068,633
Total Municipal Bonds			$	215,656,704
Floating Rate Demand Notes – 1.2%
East Baton Rouge, LA, Pollution Control Rev. (Exxon Mobil Corp.), 3.09%, due 4/01/08	$	100,000	$	100,000
Lincoln County, WY, Pollution Control Rev. (Exxon Mobil Corp.), “A”, 3.19%, due 4/01/08		500,000		500,000
Lincoln County, WY, Pollution Control Rev. (Exxon Mobil Corp.), “B”, 3.19%, due 4/01/08		200,000		200,000
Lincoln County, WY, Pollution Control Rev. (Exxon Mobil Corp.), “C”, 3.19%, due 4/01/08		495,000		495,000
Mt. Vernon Industrial Pollution Control Rev. (General Electric Co.), 3.19%, due 4/01/08		300,000		300,000
Total Floating Rate Demand Notes			$	1,595,000
Total Investments			$	217,251,704

12

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 2/29/08 - continued

Other Assets, Less Liabilities – 3.1%		4,114,008
Preferred shares (Issued by the trust) – (68.5)%		(90,000,000	)
Net assets applicable to common shares – 100.0%	$	131,365,712

(a) Mandatory tender date is earlier than stated maturity date.

(c) Refunded bond.

(f) All or a portion of the security has been segregated as collateral for an open futures contract.

(n) Securities exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be sold in the ordinary course of business in transactions exempt from registration, normally to qualified institutional buyers. At period end, the aggregate value of these securities was $4,661,082 representing 3.5% of net assets.

(z) Restricted securities are not registered under the Securities Act of 1933 and are subject to legal restrictions on resale. These securities generally may be resold in transactions exempt from registration or to the public if the securities are subsequently registered. Disposal of these securities may involve time-consuming negotiations and prompt sale at an acceptable price may be difficult. The fund holds the following restricted securities:

Restricted Securities	Acquisition Date	Acquisition Cost		Current Market Value
Agua Caliente Band of Cahuilla Indians, CA, 5.6%, 2013	7/22/03	$	776,212	$	790,221
Cabazon Band Mission Indians, CA, 8.375%, 2015	10/04/04		170,000		175,239
Cabazon Band Mission Indians, CA, 8.75%, 2019	10/04/04		720,000		743,940
Resolution Trust Corp., Pass-Through Certificates, “1993”, 8.5%, 2016	10/17/01 -1/14/02		455,481		448,795
Total Restricted Securities				$	2,158,195
% of Net Assets					1.6%

The following abbreviations are used in this report and are defined:

COP	Certificate of Participation
ETM	Escrowed to Maturity
FHLMC	Federal Home Loan Mortgage Corp.
FRN	Floating Rate Note. Interest rate resets periodically and may not be the rate reported at period end.
Insurers
AMBAC	AMBAC Indemnity Corp.
FGIC	Financial Guaranty Insurance Co.
FHA	Federal Housing Administration
FSA	Financial Security Assurance Inc.
GNMA	Government National Mortgage Assn.
MBIA	MBIA Insurance Corp.

See attached supplemental information. For more information see notes to financial statements as disclosed in the most recent semiannual or annual report.

13

MFS High Yield Municipal Trust

Supplemental Information (Unaudited) 2/29/08

(1) Fair Value Disclosure

The fund adopted FASB Statement No. 157, Fair Value Measurements (the “Statement”) in this reporting period. This Statement provides a single definition of fair value, a hierarchy for measuring fair value and expanded disclosures about fair value measurements.

Various inputs are used in determining the value of the fund’s investments. These inputs are categorized into three broad levels. Level 1 include quoted prices in active markets for identical assets or liabilities. Level 2 include other significant observable market-based inputs (including quoted prices for similar securities, interest rates, prepayment speed, credit risk, etc.). Level 3 include unobservable inputs, which may include the adviser’s own assumptions in determining the fair value of investments. Other financial instruments are derivative instruments not reflected in Total Investments, such as futures, forwards, swap contracts and written options, which are valued at the unrealized appreciation/depreciation on the instrument. The following is a summary of the levels used as of February 29, 2008 in valuing the fund’s assets carried at market value:

	Level 1			Level 2		Level 3		Total
Investments in Securities	$	—		$	217,251,704	$	—	$	217,251,704
Other Financial Instruments		(2,431,025	)		—		—		(2,431,025	)

(2) Portfolio Securities

The cost and unrealized appreciation and depreciation in the value of the investments owned by the fund, as computed on a federal income tax basis, are as follows:

Aggregate Cost	$	227,180,028
Gross unrealized appreciation	$	6,121,470
Gross unrealized depreciation		(16,049,794	)
Net unrealized appreciation (depreciation)	$	(9,928,324	)

The aggregate cost above includes prior fiscal year end tax adjustments.

(3) Derivative Contracts

Futures contracts outstanding at 2/29/08

Description	Contracts	Value		Expiration Date	Unrealized Appreciation (Depreciation)
U.S. Treasury Bond (Short)	92	$	10,913,500	Jun-08	$	(346,041	)
U.S. Treasury Note 10 yr (Short)	693		81,275,906	Jun-08		(2,084,984	)
					$	(2,431,025	)

At February 29, 2008, the fund had sufficient cash and/or other liquid securities to cover any commitments under these derivative contracts.

14

ITEM 2. CONTROLS AND PROCEDURES.

(a) Based upon their evaluation of the effectiveness of the registrant’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940 (the “Act”)) as conducted within 90 days of the filing date of this Form N-Q, the registrant’s principal financial officer and principal executive officer have concluded that those disclosure controls and procedures provide reasonable assurance that the material information required to be disclosed by the registrant on this report is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms.

(b) There were no changes in the registrant’s internal controls over financial reporting (as defined in Rule 30a-3(d) under the Act) that occurred during the registrant’s last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.

ITEM 3. EXHIBITS.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the Act (17 CFR 270.30a-2): Attached hereto.

Notice

A copy of the Agreement and Declaration of Trust, as amended, of the Registrant is on file with the Secretary of State of The Commonwealth of Massachusetts and notice is hereby given that this instrument is executed on behalf of the Registrant by an officer of the Registrant as an officer and not individually and the obligations of or arising out of this instrument are not binding upon any of the Trustees or shareholders individually, but are binding only upon the assets and property of the respective constituent series of the Registrant.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Registrant: MFS HIGH YIELD MUNICIPAL TRUST
By (Signature and Title)*	ROBERT J. MANNING
	Robert J. Manning, President
Date: April 14, 2008

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)*	ROBERT J. MANNING
	Robert J. Manning, President (Principal Executive Officer)
Date: April 14, 2008

By (Signature and Title)*	MARIA F. DWYER
	Maria F. Dwyer, Treasurer (Principal Financial Officer and Accounting Officer)
Date: April 14, 2008

* Print name and title of each signing officer under his or her signature.