N-Q

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: August 31, 2009

ITEM 1. SCHEDULE OF INVESTMENTS.

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09

Issuer	Shares/Par		Value ($)
Municipal Bonds – 164.8%
Airport & Port Revenue – 4.6%
Branson, MO, Regional Airport Transportation Development District Airport Rev., “B”, 6%, 2037	$	460,000	$	300,743
Dallas Fort Worth, TX, International Airport Rev. Improvement, “B”, FSA, 5%, 2025		3,000,000		2,874,600
New York, NY, City Industrial Development Authority Rev. (Terminal One Group Assn.), 5.5%, 2021		500,000		477,165
Port Authority NY & NJ, Cons Thirty Seventh, FSA, 5.125%, 2030		1,450,000		1,434,340
			$	5,086,848
General Obligations - General Purpose – 0.8%
Commonwealth of Puerto Rico Government Development Bank, “B”, 5%, 2015	$	400,000	$	408,136
Luzerne County, PA, FSA, 6.75%, 2023		455,000		469,797
			$	877,933
General Obligations - Improvement – 0.3%
Guam Government, “A”, 6.75%, 2029	$	140,000	$	141,420
Guam Government, “A”, 7%, 2039		160,000		160,902
			$	302,322
General Obligations - Schools – 2.2%
Beverly Hills, CA, Unified School District (Election of 2008), 0%, 2029	$	2,195,000	$	737,981
Beverly Hills, CA, Unified School District (Election of 2008), 0%, 2031		275,000		80,435
Beverly Hills, CA, Unified School District (Election of 2008), 0%, 2032		280,000		75,891
Beverly Hills, CA, Unified School District (Election of 2008), 0%, 2033		560,000		140,734
Irving, TX, Independent School District, “A”, PSF, 0%, 2016		1,000,000		820,030
Los Angeles, CA, Unified School District, “D”, 5%, 2034		165,000		165,243
San Jacinto, TX, Community College District, 5.125%, 2038		430,000		435,728
			$	2,456,042
Healthcare Revenue - Hospitals – 38.0%
Allegheny County, PA, Hospital Development Authority Rev. (University of Pittsburgh Medical Center), “A”, 5.375%, 2029	$	440,000	$	446,252
Allegheny County, PA, Hospital Development Authority Rev. (West Penn Allegheny Health), “A”, 5%, 2028		435,000		293,595
Allegheny County, PA, Hospital Development Authority Rev. (West Penn Allegheny Health), “A”, 5.375%, 2040		625,000		402,806
Atchison, KS, Hospital Rev. (Atchison Hospital Assn.), “A”, 6.75%, 2030		320,000		283,763
Brunswick, GA, Hospital Authority Rev. (Glynn-Brunswick Memorial Hospital), 5.625%, 2034		170,000		167,195
California Health Facilities Financing Authority Rev. (St. Joseph Health System), “A”, 5.75%, 2039		185,000		186,737
California Health Facilities Financing Authority Rev. (Sutter Health), “A”, 5%, 2042		500,000		431,325
California Statewide Communities Development Authority Rev. (Catholic Healthcare West) “K”, ASSD GTY, 5.5%, 2041		625,000		629,688
California Statewide Communities Development Authority Rev. (Catholic Healthcare West) “L”, ASSD GTY, 5.25%, 2041		870,000		852,791
California Statewide Communities Development Authority Rev. (Children’s Hospital), 5%, 2047		290,000		206,863
California Statewide Communities Development Authority Rev. (St. Joseph Health System), FGIC, 5.75%, 2047		635,000		632,206
Conway, AR, Hospital Rev. (Conway Regional Medical Center), “A”, 6.4%, 2029		350,000		337,404
Conway, AR, Hospital Rev. (Conway Regional Medical Center), “B”, 6.4%, 2029		850,000		819,409
Delaware County, PA, Authority Rev. (Mercy Health Corp.), ETM, 6%, 2016 (c)		965,000		1,011,735
Delaware County, PA, Authority Rev. (Mercy Health Corp.), ETM, 6%, 2026 (c)		500,000		573,495
Dickinson County, MI, Healthcare System Hospital Rev., 5.7%, 2018		770,000		727,388
Garden City, MI, Hospital Finance Authority Rev. (Garden City Hospital), 5%, 2038		500,000		254,150
Genesee County, NY, Industrial Development Agency Civic Facility Rev. (United Memorial Medical Center), 5%, 2027		90,000		61,421
Harris County, TX, Health Facilities Development Corp., Hospital Rev. (Memorial Hermann Healthcare Systems), “B”, 7.25%, 2035		205,000		222,651

1

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Healthcare Revenue - Hospitals – continued
Idaho Health Facilities Authority Rev. (IHC Hospitals, Inc.), ETM, 6.65%, 2021 (c)(f)	$	2,750,000	$	3,518,900
Illinois Finance Authority Rev. (Children’s Memorial Hospital), “A”, ASSD GTY, 5.25%, 2047		870,000		850,382
Illinois Finance Authority Rev. (Edward Hospital), “A”, AMBAC, 5.5%, 2040		1,090,000		951,396
Illinois Finance Authority Rev. (Kewanee Hospital), 5.1%, 2031		410,000		296,545
Illinois Finance Authority Rev. (Provena Health), “A”, 7.75%, 2034		485,000		514,653
Indiana Health & Educational Facilities Authority, Hospital Rev. (Community Foundation of Northwest Indiana), 5.5%, 2037		1,125,000		1,027,328
Indiana Health & Educational Facilities Finance Authority Rev. (Sisters of St. Francis Health Services, Inc.), “E”, FSA, 5.25%, 2041		660,000		637,237
Indiana Health & Educational Facilities Finance Authority, Hospital Rev. (Clarian Health), “A”, 5%, 2039		1,745,000		1,450,968
Indiana Health Facilities Financing Authority Rev. (Community Foundation of Northwest Indiana ), “A”, 6%, 2034		425,000		412,798
Johnson City, TN, Health & Educational Facilities Board Hospital Rev. (Mountain States Health), “A”, 5.5%, 2031		1,120,000		1,025,539
Johnson City, TN, Health & Educational Facilities Board Hospital Rev. (Mountain States Health), “A”, 5.5%, 2036		410,000		369,709
Kentucky Economic Development Finance Authority, Hospital Facilities Rev. (Baptist Healthcare System), “A”, 5.375%, 2024		300,000		321,357
Kentucky Economic Development Finance Authority, Hospital Facilities Rev. (Baptist Healthcare System), “A”, 5.625%, 2027		100,000		105,331
Knox County, TN, Health, Educational, Hospital & Housing Facilities Board Rev. (University Health Systems, Inc.), 5.25%, 2036		415,000		363,889
Lake County, OH, Hospital Facilities Rev. (Lake Hospital Systems, Inc.), 5.625%, 2029		435,000		416,643
Louisiana Public Facilities Authority Hospital Rev. (Lake Charles Memorial Hospital), 6.375%, 2034		830,000		701,807
Louisville & Jefferson County, KY, Metro Government Health Facilities Rev. (Jewish Hospital & St. Mary’s Healthcare), 6.125%, 2037		1,315,000		1,343,772
Louisville & Jefferson County, KY, Metropolitan Government Healthcare Systems Rev. (Norton Healthcare, Inc.), 5.25%, 2036		1,265,000		1,132,529
Lufkin, TX, Health Facilities Development Corp. Rev. (Memorial Health System), 5.5%, 2032		60,000		47,278
Lufkin, TX, Health Facilities Development Corp. Rev. (Memorial Health System), 5.5%, 2037		60,000		47,447
Maryland Health & Higher Educational Facilities Authority Rev. (Anne Arundel Health System), “A”, 6.75%, 2039		735,000		819,334
Maryland Health & Higher Educational Facilities Authority Rev. (Medstar Health), BHAC, 5.25%, 2046		440,000		443,177
Maryland Health & Higher Educational Facilities Authority Rev. (Washington County Hospital), 6%, 2043		120,000		115,968
Massachusetts Health & Educational Facilities Authority Rev. (Boston Medical Center), 5.25%, 2038		1,000,000		818,300
Massachusetts Health & Educational Facilities Authority Rev. (Jordan Hospital), “E”, 6.75%, 2033		250,000		198,645
Massachusetts Health & Educational Facilities Authority Rev. (Milford-Whitinsville Hospital), “C”, 5.25%, 2018		500,000		443,750
Massachusetts Health & Educational Facilities Authority Rev. (Quincy Medical Center), “A”, 6.5%, 2038		340,000		258,811
Montgomery, AL, Medical Clinic Board Health Care Facility Rev. (Jackson Hospital & Clinic), 5.25%, 2031		125,000		100,165
Montgomery, AL, Medical Clinic Board Health Care Facility Rev. (Jackson Hospital & Clinic), 5.25%, 2036		620,000		483,278
New Hampshire Health & Education Facilities Authority Rev. (Catholic Medical Center), “A”, 6.125%, 2012 (c)		175,000		199,736
New Hampshire Health & Education Facilities Authority Rev. (Catholic Medical Center), “A”, 6.125%, 2032		25,000		22,733

2

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Healthcare Revenue - Hospitals – continued
New Hampshire Health & Educational Facilities Authority Rev. (Memorial Hospital at Conway), 5.25%, 2021	$	530,000	$	483,016
New Hanover County, N.C., Hospital Rev., FSA, 5.125%, 2031		895,000		898,813
New Jersey Health Care Facilities, Financing Authority Rev. (St. Peter’s University Hospital), 5.75%, 2037		545,000		455,609
New Mexico Hospital Equipment Loan Council, Hospital Rev. (Rehoboth McKinley Christian Hospital), “A”, 5%, 2017		285,000		241,176
New York Dormitory Authority Rev., Non-State Supported Debt (Bronx-Lebanon Hospital Center), LOC, 6.5%, 2030		190,000		203,560
New York Dormitory Authority Rev., Non-State Supported Debt (Bronx-Lebanon Hospital Center), LOC, 6.25%, 2035		115,000		120,854
Norman, OK, Regional Hospital Authority Rev., 5.375%, 2036		235,000		176,027
Olympia, WA, Healthcare Facilities Authority Rev. (Catholic Health Initiatives), “D”, 6.375%, 2036		1,095,000		1,185,458
Orange County, FL, Health Facilities Authority Hospital Rev. (Orlando Regional Healthcare), 5.75%, 2012 (c)		150,000		170,418
Philadelphia, PA, Hospitals & Higher Education Facilities Authority Rev. (Temple University Health System), “A”, 6.625%, 2023		375,000		374,951
Philadelphia, PA, Hospitals & Higher Education Facilities Authority Rev. (Temple University Health System), “A”, 5.5%, 2030		480,000		386,866
Rhode Island Health & Educational Building Corp. Rev. (Rhode Island Hospital Foundation), “A”, ASSD GTY, 7%, 2039		660,000		735,161
Royal Oak, MI, Hospital Finance Authority Rev. (William Beaumont Hospital), 8.25%, 2039		485,000		558,182
Salida, CO, Hospital District Rev., 5.25%, 2036		735,000		534,566
Saline County, MO, Industrial Development Authority Rev. (John Fitzgibbon Memorial Hospital, Inc.), 5.625%, 2035		985,000		769,640
Skagit County, WA, Public Hospital District No. 001 Rev. (Skagit Valley Hospital), 5.75%, 2032		90,000		78,557
South Lake County, FL, Hospital District Rev. (South Lake Hospital, Inc.), 6.375%, 2034		250,000		234,433
Southwestern, IL, Development Authority Rev. (Anderson Hospital), 5.375%, 2015		500,000		488,190
Southwestern, IL, Development Authority Rev. (Anderson Hospital), 5.5%, 2020		550,000		511,847
Southwestern, IL, Development Authority Rev. (Anderson Hospital), 5.125%, 2026		500,000		427,685
Sullivan County, TN, Health, Educational & Housing Facilities Board Hospital Rev. (Wellmont Health Systems Project), “C”, 5.25%, 2036		1,085,000		767,822
Tyler, TX, Health Facilities Development Corp. (East Texas Medical Center), “A”, 5.25%, 2032		230,000		186,861
Tyler, TX, Health Facilities Development Corp. (East Texas Medical Center), “A”, 5.375%, 2037		190,000		153,805
Virginia Small Business Financing Authority Hospital Rev. (Wellmont Health Project), “A”, 5.25%, 2037		470,000		333,169
Washington Health Care Facilities Authority Rev. (Multicare Health Systems), “B”, ASSD GTY, 6%, 2039		440,000		450,912
West Contra Costa, CA, Healthcare District, AMBAC, 5.5%, 2029		105,000		104,365
West Virginia Hospital Finance Authority Rev. (Charleston Medical Center), 6.75%, 2010 (c)		605,000		646,273
Wisconsin Health & Educational Facilities Authority Rev. (Aurora Health Care, Inc.), 6.4%, 2033		350,000		352,321
Wisconsin Health & Educational Facilities Authority Rev. (Fort Healthcare, Inc.), 6.1%, 2034		750,000		708,030
Wisconsin Health & Educational Facilities Authority Rev. (Wheaton Franciscan Services), 5.75%, 2012 (c)		450,000		503,888
Wisconsin Health & Educational Facilities Authority Rev. (Wheaton Franciscan Services), 5.25%, 2034		935,000		742,287

3

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Healthcare Revenue - Hospitals – continued
Wisconsin Health & Educational Facilities Authority Rev. (Wheaton Franciscan Services), “A”, 5.25%, 2025	$	390,000	$	337,838
			$	42,302,859
Healthcare Revenue - Long Term Care – 25.7%
Abilene, TX, Health Facilities Development Corp., Retirement Facilities Rev. (Sears Methodist Retirement), “A”, 5.9%, 2025	$	750,000	$	547,523
Abilene, TX, Health Facilities Development Corp., Retirement Facilities Rev. (Sears Methodist Retirement), “A”, 7%, 2033		200,000		152,898
Boston, MA, Industrial Development Financing Authority Rev. (Springhouse, Inc.), 5.875%, 2020		235,000		203,541
Bucks County, PA, Industrial Development Authority Retirement Community Rev. (Ann’s Choice, Inc.), “A”, 6.125%, 2025		500,000		414,115
Bucks County, PA, Industrial Development Authority Retirement Community Rev. (Ann’s Choice, Inc.), “A”, 6.25%, 2035		250,000		197,398
Bucks County, PA, Industrial Development Authority Rev. (Lutheran Community Telford Center), 5.75%, 2027		90,000		68,084
Bucks County, PA, Industrial Development Authority Rev. (Lutheran Community Telford Center), 5.75%, 2037		120,000		84,104
California Statewide Communities Development Authority Rev. (Eskaton Properties, Inc.), 8.25%, 2010 (c)		695,000		760,344
Capital Projects Finance Authority, FL (Glenridge on Palmer Ranch), “A”, 8%, 2012 (c)		500,000		596,760
Chartiers Valley, PA, Industrial & Commercial Development Authority (Friendship Village), “A”, 5.75%, 2020		1,000,000		881,020
Chartiers Valley, PA, Industrial & Commercial Development Authority Rev. (Asbury Health Center), 6.375%, 2024		1,000,000		869,250
Colorado Health Facilities Authority Rev. (American Housing Foundation, Inc.), 8.5%, 2011 (c)		530,000		610,793
Colorado Health Facilities Authority Rev. (Christian Living Communities Project), “A”, 5.75%, 2037		500,000		366,740
Colorado Health Facilities Authority Rev. (Covenant Retirement Communities, Inc.), 5%, 2035		1,100,000		797,093
Colorado Health Facilities Authority Rev. (Evangelical Lutheran), “A”, 6.125%, 2038		120,000		118,627
Columbus, GA, Housing Authority Rev. (Calvary Community, Inc.), 7%, 2019		425,000		360,404
Fulton County, GA, Residential Care Facilities (Canterbury Court), “A”, 6.125%, 2026		500,000		405,250
Fulton County, GA, Residential Care Facilities, First Mortgage (Lenbrook Square Foundation, Inc.), “A”, 5%, 2029		1,500,000		1,007,145
HFDC of Central Texas, Inc., Retirement Facilities Rev. (Legacy at Willow Bend), “A”, 5.75%, 2036		600,000		408,180
Houston, TX, Health Facilities Development Corp. (Buckingham Senior Living Community), “A”, 7%, 2014 (c)		500,000		602,660
Howard County, MD, Retirement Facilities Rev. (Vantage House Corp.), “A”, 5.25%, 2033		200,000		127,658
Huntington, NY, Housing Authority Rev. (Gurwin Senior Jewish Residences), “A”, 5.875%, 2019		420,000		349,247
Huntington, NY, Housing Authority Rev. (Gurwin Senior Jewish Residences), “A”, 6%, 2029		650,000		481,611
Illinois Finance Authority Rev. (Smith Village), “A”, 6.25%, 2035		1,000,000		738,020
Illinois Health Facilities Authority Rev. (Smith Crossing), “A”, 7%, 2032		525,000		438,349
Indiana Health Facilities Financing Authority Rev. (Hoosier Care, Inc.), 7.125%, 2034		1,005,000		791,357
Iowa Finance Authority, Health Care Facilities Rev. (Care Initiatives), 9.25%, 2011 (c)		895,000		1,041,073
Iowa Finance Authority, Health Care Facilities Rev. (Care Initiatives), “B”, 5.75%, 2018		505,000		445,940
Iowa Finance Authority, Health Care Facilities Rev. (Care Initiatives), “B”, 5.75%, 2028		1,475,000		1,116,236
James City County, VA, Economic Development (WindsorMeade Project), “A”, 5.5%, 2037		440,000		233,763
Johnson City, TN, Health & Educational Facilities Board (Appalachian Christian Village), “A”, 6.25%, 2032		250,000		185,990

4

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Healthcare Revenue - Long Term Care – continued
Juneau, AK, City & Borough Non-Recourse Rev. (St. Ann’s Care Project), 6.875%, 2025	$	900,000	$	707,445
Kent County, DE, Assisted Living (Heritage at Dover LLC), 7.625%, 2030		1,120,000		923,608
Kentucky Economic Development Finance Authority Health Facilities Rev. (AHF/Kentucky-IOWA, Inc.), 8%, 2029		395,000		322,217
La Verne, CA, COP (Brethren Hillcrest Homes), “B”, 6.625%, 2025		525,000		454,498
Lancaster, PA, Industrial Development Authority Rev. (Garden Spot Village), “A”, 7.625%, 2010 (c)		325,000		343,613
Massachusetts Development Finance Agency Rev. (Adventcare), “A”, 6.75%, 2037		695,000		530,132
Massachusetts Development Finance Agency Rev. (Alliance Health of Brockton, Inc.), “A”, 7.1%, 2032		1,065,000		860,584
Massachusetts Development Finance Agency Rev. (Linden Ponds, Inc.), “A”, 5.5%, 2027		185,000		125,658
Massachusetts Development Finance Agency Rev. (Linden Ponds, Inc.), “A”, 5.75%, 2035		45,000		29,064
Massachusetts Development Finance Agency Rev. (Loomis Communities, Inc.), “A”, 5.625%, 2015		220,000		206,281
Massachusetts Development Finance Agency Rev. (Loomis Communities, Inc.), “A”, 6.9%, 2032		125,000		114,138
Massachusetts Industrial Finance Agency Rev. (GF/Massachusetts, Inc.), 8.3%, 2023		755,000		409,150
Metropolitan Government of Nashville & Davidson County, TN, Health & Educational Facilities Board Rev. (Blakeford at Green Hills), 5.65%, 2024		575,000		451,668
Montgomery County, PA, Industrial Development Authority Rev. (Whitemarsh Continuing Care), 6.125%, 2028		150,000		103,784
Montgomery County, PA, Industrial Development Authority Rev. (Whitemarsh Continuing Care), 6.25%, 2035		600,000		391,572
New Jersey Economic Development Authority Rev. (Lions Gate), “A”, 5.75%, 2025		400,000		333,620
New Jersey Economic Development Authority Rev. (Lions Gate), “A”, 5.875%, 2037		300,000		229,269
New Jersey Economic Development Authority Rev. (Seabrook Village, Inc.), 5.25%, 2026		500,000		393,435
New Jersey Economic Development Authority Rev. (Seabrook Village, Inc.), 5.25%, 2036		500,000		356,445
New Jersey Economic Development Authority Rev. (Seabrook Village, Inc.), “A”, 8.25%, 2010 (c)		700,000		765,058
Roseville, MN, Elder Care Facilities (Care Institute, Inc.), 7.75%, 2023		1,630,000		1,266,282
Sartell, MN, Health Care & Housing Authority Rev. (The Foundation for Health Care), “A”, 6.625%, 2029		1,025,000		891,022
Savannah, GA, Economic Development Authority, First Mortgage (Marshes of Skidway), “A”, 7.4%, 2034		350,000		295,922
Shelby County, TN, Health, Educational & Housing Facilities Board Rev. (Germantown Village), “A”, 7.25%, 2034		300,000		247,164
South Carolina Jobs & Economic Development Authority Rev. (Woodlands at Furman), “A”, 6%, 2027		280,000		198,083
South Carolina Jobs & Economic Development Authority Rev. (Woodlands at Furman), “A”, 6%, 2042		260,000		164,882
South Carolina Jobs & Economic Development Authority, Health Facilities Rev. (Wesley Commons), 5.3%, 2036		200,000		131,240
St. Johns County, FL, Industrial Development Authority (Glenmoor Project), “A”, 5.25%, 2026		500,000		352,375
Westmoreland County, PA, Industrial Development Authority Rev. (Redstone Retirement Community), “A”, 5.875%, 2032		600,000		450,702
Westmoreland County, PA, Industrial Development Retirement Authority Rev. (Redstone Retirement Community), “A”, 5.75%, 2026		1,250,000		991,150
Wisconsin Health & Educational Facilities Authority Rev. (All Saints Assisted Living Project), 6%, 2037		180,000		124,510
			$	28,565,744

5

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Healthcare Revenue - Other – 0.7%
Massachusetts Health & Educational Facilities Authority Rev. (Civic Investments, Inc.), “A”, 9%, 2012 (c)	$	650,000	$	773,942
Industrial Revenue - Airlines – 3.9%
Alliance Airport Authority, TX (American Airlines, Inc.), 5.25%, 2029	$	1,560,000	$	656,838
Chicago, IL, O’Hare International Airport Special Facilities Rev. (American Airlines, Inc.), 5.5%, 2030		1,455,000		612,555
Cleveland, OH, Airport Special Rev. (Continental Airlines, Inc.), 5.7%, 2019		875,000		674,931
Dallas Fort Worth, TX, International Airport Facility Improvement Corp. (American Airlines, Inc.), 5.5%, 2030		750,000		338,348
New Jersey Economic Development Authority, Special Facilities Rev. (Continental Airlines, Inc.), 9%, 2033		1,250,000		1,286,200
New York, NY, City Industrial Development Agencies Rev. (American Airlines, Inc.), 7.625%, 2025		40,000		34,164
New York, NY, City Industrial Development Agencies Rev. (American Airlines, Inc.), 7.75%, 2031		385,000		326,091
New York, NY, City Industrial Development Agency Special Facility Rev. (American Airlines, Inc.), “B”, 8.5%, 2028		500,000		424,895
			$	4,354,022
Industrial Revenue - Chemicals – 0.9%
Brazos River, TX, Harbor Navigation District (Dow Chemical Co.), “B-2”, 4.95%, 2033	$	400,000	$	334,384
Michigan Strategic Fund Ltd. Obligation Rev. (Dow Chemical Co.), 6.25%, 2014		655,000		677,132
			$	1,011,516
Industrial Revenue - Environmental Services – 2.2%
California Pollution Control Financing Authority, Solid Waste Disposal Rev. (Republic Services, Inc.), “B”, 5.25%, 2023 (b)	$	135,000	$	131,467
California Pollution Control Financing Authority, Solid Waste Disposal Rev. (Waste Management, Inc.), “C”, 5.125%, 2023		655,000		606,078
Carbon County, UT, Solid Waste Disposal Rev. (Allied Waste Industries), “A”, 7.5%, 2010		250,000		252,023
Carbon County, UT, Solid Waste Disposal Rev. (Laidlaw Environmental), “A”, 7.45%, 2017		500,000		515,920
Gulf Coast Waste Disposal Authority, TX (Waste Management, Inc.), “A”, 5.2%, 2028		360,000		314,363
New Hampshire Business Finance Authority, Solid Waste Disposal Rev. (Waste Management, Inc.), 5.2%, 2027		660,000		586,456
			$	2,406,307
Industrial Revenue - Metals – 0.4%
Director of Nevada Department of Business & Industry (Wheeling/Pittsburgh Steel), “A”, 8%, 2014	$	130,000	$	126,528
Greensville County, VA, Industrial Development Authority Rev. (Wheeling/Pittsburgh Steel), “A”, 7%, 2014		375,000		355,714
			$	482,242
Industrial Revenue - Other – 4.2%
Annawan, IL, Tax Increment Rev. (Patriot Renewable Fuels LLC), 5.625%, 2018	$	350,000	$	271,401
California Statewide Communities Development Authority Facilities (Microgy Holdings Project), 9%, 2038		400,000		339,348
Gulf Coast, TX, Industrial Development Authority Rev. (CITGO Petroleum Corp.), 8%, 2028		375,000		375,049
Houston, TX, Industrial Development Corp. (United Parcel Service, Inc.), 6%, 2023		455,000		362,212
Indianapolis, IN, Airport Authority Rev., Special Facilities (FedEx Corp.), 5.1%, 2017		500,000		465,310
Michigan Strategic Fund Rev. (Michigan Sugar Co.), “A”, 6.25%, 2015		1,000,000		923,660
New Jersey Economic Development Authority Rev. (GMT Realty LLC), “B”, 6.875%, 2037		1,000,000		744,620
Virgin Islands Government Refinery Facilities Rev. (Hovensa Coker Project), 6.5%, 2021		250,000		250,710

6

MFS High Yield Municipal Trust

PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Industrial Revenue - Other – continued
Virgin Islands Public Finance Authority, Refinery Facilities Rev. (Hovensa Coker Project), 5.875%, 2022	$	400,000	$	379,092
Will-Kankakee, IL, Regional Development Authority Rev. (Flanders Corp.), 6.5%, 2017		605,000		541,929
			$	4,653,331
Industrial Revenue - Paper – 3.2%
Beauregard Parish, LA (Boise Cascade Corp.), 6.8%, 2027	$	1,000,000	$	536,590
Bedford County, VA, Industrial Development Authority Rev. (Nekooska Packaging Corp.), 5.6%, 2025		400,000		320,932
Camden, AL, Industrial Development Board Exempt Facilities Rev., “B” (Weyerhaeuser Co.), 6.375%, 2013 (c)		400,000		456,660
Courtland AL, Industrial Development Board Solid Waste Disposal Rev. (Champion International Corp.), 6%, 2029		1,000,000		840,530
Escambia County, FL, Environmental Improvement Rev. (International Paper Co.), “A”, 5%, 2026		980,000		859,284
Escambia County, FL, Environmental Improvement Rev. (International Paper Co.), “A”, 4.75%, 2030		290,000		233,218
Phenix City, AL, Industrial Development Board Environmental Improvement Rev., “A” (MeadWestvaco Coated Board Project), 6.35%, 2035		400,000		327,316
			$	3,574,530
Miscellaneous Revenue - Entertainment & Tourism – 2.1%
Agua Caliente Band of Cahuilla Indians, CA, 5.6%, 2013 (z)	$	635,000	$	590,836
Cabazon Band Mission Indians, CA, 8.375%, 2015 (z)		150,000		100,506
Cabazon Band Mission Indians, CA, 8.75%, 2019 (z)		720,000		478,634
Cow Creek Band of Umpqua Tribe of Indians, OR, “C”, 5.625%, 2026 (n)		650,000		455,169
Mashantucket Western Pequot Tribe, CT, “B”, 0%, 2018 (n)		1,100,000		295,889
New York Liberty Development Corp. Rev. (National Sports Museum), “A”, 6.125%, 2019 (d)		351,999		1,056
New York, NY, City Industrial Development Agency Rev. (Queens Baseball Stadium), ASSD GTY, 6.125%, 2029		30,000		33,053
New York, NY, City Industrial Development Agency Rev. (Queens Baseball Stadium), ASSD GTY, 6.375%, 2039		25,000		27,109
New York, NY, City Industrial Development Agency Rev. (Queens Baseball Stadium), ASSD GTY, 6.5%, 2046		100,000		108,579
Seminole Tribe, FL, Special Obligation Rev., “A”, 5.25%, 2027 (n)		280,000		242,813
			$	2,333,644
Miscellaneous Revenue - Other – 3.2%
Austin, TX, Convention Center (Convention Enterprises, Inc.), “A”, SYNCORA, 5.25%, 2024	$	115,000	$	93,900
Capital Trust Agency, FL (Aero Syracuse LLC), 6.75%, 2032		350,000		272,496
Citizens Property Insurance Corp., “A-1”, ASSD GTY, 5.5%, 2016		960,000		1,005,571
Dallas, TX, Civic Center Convention Complex Rev., ASSD GTY, 5.25%, 2034		845,000		866,708
Massachusetts Development Finance Agency (Boston Biomedical Research), 5.65%, 2019		620,000		581,219
Summit County, OH, Port Authority Building Rev. (Twinsburg Township), “D”, 5.125%, 2025		630,000		525,174
V Lakes Utility District Ranking Water Systems Rev., 7%, 2037		300,000		246,267
			$	3,591,335
Multi-Family Housing Revenue – 8.2%
Broward County, FL, Housing Finance Authority Rev. (Chaves Lakes Apartments Ltd.), “A”, 7.5%, 2040	$	500,000	$	455,085
Capital Trust Agency, FL, Housing Rev. (Atlantic Housing Foundation), “B”, 7%, 2032		635,000		541,915
Charter Mac Equity Issuer Trust, FHLMC, 6%, 2019 (n)		1,000,000		1,019,710
Charter Mac Equity Issuer Trust, “B”, FHLMC, 7.6%, 2010 (b)(n)		500,000		510,450
Clay County, FL, Housing Finance Authority Rev. (Madison Commons Apartments), “A”, 7.45%, 2040		495,000		434,610

7

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PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Multi-Family Housing Revenue – continued
District of Columbia Housing Finance Agency (Henson Ridge), “E”, FHA, 5.1%, 2037	$	655,000	$	615,222
Durham, NC, Durham Housing Authority Rev. (Magnolia Pointe Apartments), 5.65%, 2038 (b)		932,453		712,562
El Paso County, TX, Housing Finance Corp. (American Housing Foundation, Inc.), “D”, 10%, 2032		290,000		259,562
El Paso County, TX, Housing Finance Corp. (American Housing Foundation, Inc.), “C”, 8%, 2032		285,000		250,398
Massachusetts Housing Finance Agency Rev., “B”, 5%, 2030		500,000		493,605
Massachusetts Housing Finance Agency Rev., “E”, 5%, 2028		500,000		479,665
Minneapolis, MN, Student Housing Rev. (Riverton Community Housing Project), “A”, 5.7%, 2040		500,000		362,375
Mississippi Home Corp., Rev. (Kirkwood Apartments), 6.8%, 2037		605,000		416,682
MuniMae TE Bond Subsidiary LLC, 5.8%, 2049 (z)		1,000,000		600,010
New Mexico Mortgage Finance Authority, Multi-Family Housing Rev. (Sun Pointe Apartments), “E”, FHA, 4.8%, 2040		500,000		440,800
Resolution Trust Corp., Pass-Through Certificates, “1993”, 8.5%, 2016 (z)		455,481		422,586
Seattle, WA, Housing Authority Rev., Capped Fund Program (High Rise Rehab), “I”, FSA, 5%, 2025		500,000		487,520
Wilmington, DE, Multi-Family Housing Rev. (Electra Arms Senior Associates), 6.25%, 2028		830,000		646,022
			$	9,148,779
Sales & Excise Tax Revenue – 4.0%
Bolingbrook, IL, Sales Tax Rev., 6.25%, 2024	$	500,000	$	219,830
Massachusetts School Building Authority, Dedicated Sales Tax Rev., AMBAC, 4.75%, 2032		840,000		846,619
Metropolitan Pier & Exposition Authority, State Tax Rev., NATL, 0%, 2015		3,000,000		2,443,410
Metropolitan Pier & Exposition Authority, State Tax Rev., ETM, FGIC, 0%, 2014 (c)		1,010,000		899,799
			$	4,409,658
Single Family Housing - Local – 1.4%
Minneapolis & St. Paul Housing Authority Rev. (City Living), “A-2”, GNMA, 5%, 2038	$	660,829	$	614,802
Pittsburgh, PA, Urban Redevelopment Authority Rev., “C”, GNMA, 4.8%, 2028		1,000,000		988,930
			$	1,603,732
Single Family Housing - State – 4.6%
California Housing Finance Agency Rev., “G”, 5.5%, 2042	$	495,000	$	482,165
California Housing Finance Agency Rev., “J”, 5.75%, 2047		1,455,000		1,398,008
Colorado Housing & Finance Authority, “A”, 5.5%, 2029		1,315,000		1,356,357
Iowa Finance Authority, Single Family Mortgage Rev., “E”, 5.4%, 2032		895,000		912,354
Kentucky Counties Single Family Mortgage Rev., “A”, NATL, 9%, 2016		5,000		5,000
North Dakota Housing Finance Agency Rev., “A”, 4.85%, 2021		405,000		402,096
Virginia Housing Development Authority, Commonwealth Mortgage, “A-5”, 4.4%, 2015		210,000		210,582
Virginia Housing Development Authority, Commonwealth Mortgage, “A-5”, 4.4%, 2015		340,000		341,023
			$	5,107,585
State & Agency - Other – 0.5%
Commonwealth of Puerto Rico (Mepsi Campus), “A”, 6.25%, 2024	$	100,000	$	87,998
Commonwealth of Puerto Rico (Mepsi Campus), “A”, 6.5%, 2037		500,000		416,090
			$	504,088
State & Local Agencies – 5.5%
Chesterfield County, VA, Economic Development Authority Pollution Control Rev., “A”, 5%, 2023	$	880,000	$	905,766
Dorchester County, SC, School District No. 2, Growth Remedy Opportunity Tax Hike, 5.25%, 2029		500,000		507,970
Laurens County, SC, School District No. 55, Installment Purchase Rev., 5.25%, 2030		700,000		629,650
Michigan Building Authority Rev., Facilities Program, “I”, 5%, 2024		1,000,000		992,610
New York Metropolitan Transportation Authority, “A”, 5.125%, 2029		800,000		805,696

8

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PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
State & Local Agencies – continued
Newberry, SC, Investing in Children’s Education (Newberry County School District Program), 5%, 2030	$	400,000	$	346,572
Philadelphia, PA, Municipal Authority Rev., 6.5%, 2034		135,000		138,668
Puerto Rico Public Finance Corp., “E”, ETM, 6%, 2026 (c)		80,000		97,306
Puerto Rico Public Finance Corp., Unrefunded, “E”, 6%, 2026		820,000		997,382
Wisconsin General Fund Annual Appropriation Rev., “A”, 5.75%, 2033		660,000		717,011
			$	6,138,631
Student Loan Revenue – 0.6%
Massachusetts Educational Financing Authority, Education Loan Rev., “H”, ASSD GTY, 6.35%, 2030	$	625,000	$	645,706
Tax - Other – 1.3%
Dallas County, TX, Flood Control District, 7.25%, 2032	$	750,000	$	765,015
New York, NY, City Transitional Finance Authority Building Aid Rev., “S-3”, 5.25%, 2039		440,000		450,432
Virgin Islands Public Finance Authority Rev. (Diageo Project), “A”, 6.75%, 2037		205,000		206,324
			$	1,421,771
Tax Assessment – 9.7%
Atlanta, GA, Tax Allocation (Eastside Project), “B”, 5.4%, 2020	$	500,000	$	431,900
Ave Maria Stewardship Community District, FL, “A”, 5.125%, 2038		150,000		76,896
Capital Region Community Development District, FL, Capital Improvement Rev., “A”, 7%, 2039		235,000		168,523
Celebration Community Development District, FL, “A”, 6.4%, 2034		700,000		652,463
Channing Park Community Development District, FL, 5.3%, 2038		400,000		205,828
Chicago, IL, Tax Increment Allocation (Pilsen Redevelopment), “B”, 6.75%, 2022		310,000		272,812
Du Page County, IL, Special Service Area No. 31 Special Tax (Monarch Landing Project), 5.625%, 2036		250,000		160,095
Durbin Crossing Community Development District, FL, Special Assessment, “B-1”, 4.875%, 2010		150,000		107,100
Grand Bay at Doral Community Development District, FL, “A”, 6%, 2039		90,000		48,240
Grand Bay at Doral Community Development District, FL, “B”, 6%, 2017		545,000		387,119
Heritage Harbour North Community Development District, FL, Capital Improvement Rev., 6.375%, 2038		315,000		214,515
Homestead 50 Community Development District, FL, “A”, 6%, 2037 (a)		370,000		200,895
Homestead 50 Community Development District, FL, “B”, 5.9%, 2013 (a)		170,000		121,389
Huntington Beach, CA, Community Facilities District, Special Tax (Grand Coast Resort), “2000-1”, 6.45%, 2031		500,000		436,695
Lincoln, CA, Special Tax (Community Facilities District ), “2003-1”, 5.55%, 2013 (c)		440,000		513,748
Lincolnshire, IL, Special Service Area No. 1 (Sedgebrook Project), 6.25%, 2034		250,000		166,800
Magnolia Park Community Development District, FL, Special Assessment, “A”, 6.15%, 2039		615,000		376,731
Main Street Community Development District, FL, “A”, 6.8%, 2038		290,000		217,074
Main Street Community Development District, FL, “B”, 6.9%, 2017		225,000		197,737
Northwest Metropolitan District No. 3, CO, 6.25%, 2035		500,000		293,090
Oakmont Grove Community Development District, CA, “A”, 5.4%, 2038 (a)		300,000		124,962
Ohio County, WV, Commission Tax Increment Rev. (Fort Henry Centre), “A”, 5.85%, 2034		125,000		93,538
Orlando, FL, Special Assessment Rev. (Conroy Road Interchange Project), “A”, 5.5%, 2010		25,000		24,929
Orlando, FL, Special Assessment Rev. (Conroy Road Interchange Project), “A”, 5.8%, 2026		300,000		259,062
Plano, IL, Special Service Area No. 4 (Lakewood Springs Project Unit 5-B), 6%, 2035		1,487,000		1,074,625
Portage, IN, Economic Development Rev. (Ameriplex Project), 5%, 2027		260,000		208,853
San Diego, CA, Redevelopment Agency, Tax Allocation, FSA, 0%, 2018		1,015,000		685,003
Sarasota National Community Development District, FL, Special Assessment Rev., 5.3%, 2039		800,000		416,920

9

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PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Tax Assessment – continued
Sweetwater Creek Community Development District, FL, Capital Improvement Rev., 5.5%, 2038	$	195,000	$	110,643
Tolomato Community Development District, FL, Special Assessment, 6.65%, 2040		585,000		400,760
Tuscany Reserve Community Development District, FL, Special Assessment, “B”, 5.25%, 2016		185,000		122,527
Volo Village, IL, Special Service Area No. 3, Special Tax (Symphony Meadows Project), “1”, 6%, 2036		484,000		279,229
West Villages Improvement District, FL, Special Assessment Rev. (Unit of Development No. 3), 5.5%, 2037		490,000		232,216
Westchester, FL, Community Development District No. 1 (Community Infrastructure), 6.125%, 2035		275,000		183,076
Westridge, FL, Community Development District, Capital Improvement Rev., 5.8%, 2037 (d)		960,000		385,690
Wyandotte County-Kansas City, KS, Unified Government Transportation Development District (Legends Village West Project), 4.875%, 2028		580,000		377,157
Yorba Linda, CA, Redevelopment Agency, Tax Allocation Rev., “A”, NATL, 0%, 2024		1,325,000		562,198
			$	10,791,038
Tobacco – 8.7%
Buckeye, OH, Tobacco Settlement Financing Authority, “A-2”, 5.875%, 2030	$	1,610,000	$	1,334,674
Buckeye, OH, Tobacco Settlement Financing Authority, “A-2”, 5.875%, 2047		2,810,000		2,047,703
Buckeye, OH, Tobacco Settlement Financing Authority, “A-2”, 6.5%, 2047		785,000		625,253
California County, CA, Tobacco Securitization Agency, Tobacco Settlement Rev. (Los Angeles County), 0%, 2046		3,500,000		80,045
Golden State, CA, Tobacco Securitization Corp., Tobacco Settlement Rev., “A-1”, 6.25%, 2013 (c)		1,350,000		1,496,232
Inland Empire, CA, Tobacco Securitization Corp., Tobacco Settlement Rev., Asset Backed, “C-1”, 0%, 2036		1,815,000		179,249
Michigan Tobacco Settlement Finance Authority Rev., Asset Backed, “A”, 6%, 2048		1,710,000		1,295,787
Rhode Island Tobacco Settlement Authority, 6%, 2023		1,675,000		1,574,014
Tobacco Settlement Authority of Washington Rev., Asset Backed, 6.625%, 2032		500,000		478,120
Virginia Tobacco Settlement Financing Corp., “B-1”, 5%, 2047		830,000		558,258
			$	9,669,335
Toll Roads – 4.8%
E-470 Public Highway Authority, CO, “B”, 0%, 2010 (c)	$	8,750,000	$	1,319,238
E-470 Public Highway Authority, CO, “B”, NATL, 0%, 2018		1,500,000		858,615
Pennsylvania Turnpike Commission Rev., Capital Appreciation, “C”, FSA, 0% to 2016, 6.25% to 2033		1,440,000		1,023,710
San Joaquin Hills, CA, Transportation Corridor Agency Toll Road Rev., “A”, NATL, 0%, 2015		3,000,000		2,116,110
			$	5,317,673
Universities - Colleges – 6.6%
California Educational Facilities Authority Rev. (University of Southern California), “A”, 5.25%, 2038	$	1,270,000	$	1,329,690
California Municipal Finance Authority Rev. (Biola University), 5.8%, 2028		100,000		96,639
Florida State University Board of Governors, System Improvement Rev., 6.25%, 2030		1,000,000		1,126,000
Grand Valley, MI, State University Rev., 5.5%, 2027		135,000		138,472
Grand Valley, MI, State University Rev., 5.625%, 2029		65,000		66,723
Harris County, TX, Cultural Education Facilities Rev. (Baylor College of Medicine), “D”, 5.625%, 2032		280,000		284,903
Massachusetts Health & Educational Facilities Authority Rev. (Simmons College), “I”, 8%, 2029		255,000		270,267
Savannah, GA, Economic Development Authority Rev. (AASU Student Union LLC), ASSD GTY, 5.125%, 2039		1,320,000		1,351,310
University of Illinois Rev. (Auxiliary Facilities Systems), “A”, 5.125%, 2029		1,880,000		1,961,611
University of Southern Indiana Rev., Student Fee, “J”, ASSD GTY, 5.75%, 2028		300,000		327,816

10

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PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Universities - Colleges – continued
University of Southern Mississippi Educational Building Corp. Rev. (Campus Facilities Project), 5.25%, 2032	$	265,000	$	279,111
University of Southern Mississippi Educational Building Corp. Rev. (Campus Facilities Project), 5.375%, 2036		80,000		84,267
			$	7,316,809
Universities - Dormitories – 0.4%
California Statewide Communities Development Authority Rev. (Lancer Educational Student Housing Project), 5.625%, 2033	$	735,000	$	474,024
Universities - Secondary Schools – 1.2%
California Statewide Communities Development Authority Rev., COP (Crossroads Schools for the Arts & Sciences), 6%, 2028	$	980,000	$	910,949
Colorado Housing Finance Development Rev. (Evergreen Country Day School), 5.875%, 2037		175,000		115,206
Lee County, FL, Industrial Development Authority Rev. (Lee Charter Foundation), “A”, 5.375%, 2037		535,000		330,047
			$	1,356,202
Utilities - Cogeneration – 0.7%
Puerto Rico Industrial, Tourist, Educational, Medical & Environmental Central Facilities (Cogeneration Facilities - AES Puerto Rico Project), 6.625%, 2026	$	320,000	$	321,789
Suffolk County, NY, Industrial Development Agency Rev. (Nissequoque Cogeneration Partners Facilities), 5.5%, 2023		550,000		459,877
			$	781,666
Utilities - Investor Owned – 7.0%
Brazos River Authority, TX, Pollution Control Rev. (TXU Electric Co. LLC), “C”, 5.75%, 2036 (b)	$	220,000	$	179,021
Brazos River Authority, TX, Pollution Control Rev. (TXU Electric Co. LLC), “C”, 6.75%, 2038		555,000		278,893
Brazos River Authority, TX, Pollution Control Rev. (TXU Electric Co. LLC), “D”, 5.4%, 2029 (b)		45,000		31,203
Bryant, IL, Pollution Control Rev. (Central Illinois Light Co.), 5.9%, 2023		975,000		975,624
Chula Vista, CA, Industrial Development Rev. (San Diego Gas), 5.875%, 2034		245,000		248,146
Clark County, NV, Industrial Development Rev. (Nevada Power Co. Project), “A”, 5.9%, 2032		1,500,000		1,359,660
Maricopa County, AZ, Pollution Control Corp., Pollution Control Rev. (Arizona Public Service Co.), “D”, 6%, 2029 (b)		475,000		494,898
Massachusetts Development Finance Agency, Solid Waste Disposal Rev. (Dominion Energy Brayton), 5.75%, 2042 (b)		85,000		89,698
Matagorda County, TX, Pollution Control Rev. (Central Power & Light Co.), “A”, 6.3%, 2029		275,000		285,431
Mississippi Business Finance Corp., Pollution Control Rev. (Systems Energy Resources Project), 5.875%, 2022		1,500,000		1,412,820
New Hampshire Business Finance Authority, Pollution Control Rev. (Public Service of New Hampshire), “B”, NATL, 4.75%, 2021		250,000		242,790
Owen County, KY, Waterworks System Rev. (American Water Co. Project), “A”, 6.25%, 2039		205,000		210,543
Pennsylvania Economic Development Financing Authority (Allegheny Energy Supply Co. LLC), 7%, 2039		600,000		619,332
Red River Authority, TX, Pollution Control Rev. (AEP Texas Central Co.), NATL, 4.45%, 2020		410,000		362,555
Sabine River Authority, TX, Pollution Control Rev. (TXU Electric Co. LLC), 5.2%, 2028		185,000		91,586
Sabine River Authority, TX, Pollution Control Rev. (TXU Electric Co. LLC), 5.75%, 2030 (b)		155,000		126,128
Sweetwater County, WY, Pollution Control Rev. (Idaho Power Co.), 5.25%, 2026		540,000		547,857
West Feliciana Parish, LA, Pollution Control Rev. (Entergy Gulf States), 6.6%, 2028		270,000		270,400
			$	7,826,585

11

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PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Issuer	Shares/Par		Value ($)
Municipal Bonds – continued
Utilities - Municipal Owned – 0.1%
Harris County, TX, Cultural Education Facilities Financial Corp., Thermal Utilities Rev. (Teco Project), “A”, 5.25%, 2035	$	140,000	$	141,310
Utilities - Other – 3.8%
California M-S-R Energy Authority Gas Rev., “A”, 7%, 2034	$	155,000	$	166,535
California M-S-R Energy Authority Gas Rev., “A”, 6.5%, 2039		335,000		337,623
Indiana Bond Bank Special Program, Gas Rev., “A”, 5.25%, 2018		230,000		235,509
Main Street Natural Gas, Inc., GA, Gas Project Rev., “A”, 5.5%, 2028		335,000		302,003
Main Street Natural Gas, Inc., GA, Gas Project Rev., “B”, 5%, 2019		325,000		301,415
Public Authority for Colorado Energy Natural Gas Purchase Rev., 6.5%, 2038		25,000		25,326
Salt Verde Financial Corp., AZ, Senior Gas Rev., 5%, 2037		705,000		586,081
Tennessee Energy Acquisition Corp., Gas Rev., “A”, 5.25%, 2021		1,710,000		1,665,489
Tennessee Energy Acquisition Corp., Gas Rev., “A”, 5.25%, 2022		270,000		261,598
Tennessee Energy Acquisition Corp., Gas Rev., “A”, 5.25%, 2026		165,000		155,763
Tennessee Energy Acquisition Corp., Gas Rev., “C”, 5%, 2025		240,000		222,430
			$	4,259,772
Water & Sewer Utility Revenue – 3.3%
Atlanta, GA, Water & Wastewater Rev., “A”, 6%, 2022	$	370,000	$	388,633
Birmingham, AL, Waterworks Board Water Rev., “A”, ASSD GTY, 5.125%, 2034		595,000		606,653
Commonwealth of Puerto Rico Aqueduct & Sewer Authority Rev., “A”, 6%, 2038		655,000		656,716
Commonwealth of Puerto Rico Aqueduct & Sewer Authority Rev., “A”, 6%, 2044		135,000		134,595
Detroit, MI, Sewer Disposal System Rev., “B”, FSA, 7.5%, 2033		515,000		621,533
New York, NY, Municipal Water Finance Authority, Water & Sewer Systems Rev. “DD”, 4.75%, 2035		790,000		781,831
Surprise, AZ, Municipal Property Corp., 4.9%, 2032		700,000		530,698
			$	3,720,659
Total Municipal Bonds				183,407,640
Other Assets, Less Liabilities – 2.6%				2,871,259
Preferred Shares (Issued by the Fund) – (67.4)%				(75,000,000	)
Net assets applicable to common shares – 100.0%			$	111,278,899

(a) Non-income producing security.

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

(c) Refunded bond.

(d) Non-income producing security - in default.

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

(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 $2,524,031, representing 2.3% of net assets, applicable to common shares.

(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	Cost		Current Market Value
Agua Caliente Band of Cahuilla Indians, CA, 5.6%, 2013	7/22/03	$	635,717	$	590,836
Cabazon Band Mission Indians, CA, 8.375%, 2015	10/04/04		150,000		100,506
Cabazon Band Mission Indians, CA, 8.75%, 2019	10/04/04		720,000		478,634
MuniMae TE Bond Subsidiary LLC, 5.8%, 2049	10/14/04		1,000,000		600,010
Resolution Trust Corp., Pass-Through Certificates, “1993”, 8.5%, 2016	10/17/01-1/14/02		455,481		422,586
Total Restricted Securities				$	2,192,572
% of Net Assets Applicable to Common Shares					2.0	%

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

COP	Certificate of Participation
ETM	Escrowed to Maturity
LOC	Letter of Credit

12

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PORTFOLIO OF INVESTMENTS (Unaudited) 8/31/09 - continued

Insurers
AMBAC	AMBAC Indemnity Corp.
ASSD GTY	Assured Guaranty Insurance Co.
BHAC	Berkshire Hathaway Assurance Corp.
FGIC	Financial Guaranty Insurance Co.
FHA	Federal Housing Administration
FHLMC	Federal Home Loan Mortgage Corp.
FSA	Financial Security Assurance, Inc.
GNMA	Government National Mortgage Assn.
NATL	National Public Finance Guarantee Corp.
PSF	Permanent School Fund
SYNCORA	Syncora Guarantee Inc.

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) 8/31/09

(1) Investment Valuations

Debt instruments and floating rate loans (other than short-term instruments), including restricted debt instruments, are generally valued at an evaluated or composite bid as provided by a third-party pricing service. Short-term instruments with a maturity at issuance of 60 days or less generally are valued at amortized cost, which approximates market value. Futures contracts are generally valued at last posted settlement price as provided by a third-party pricing service on the market on which they are primarily traded. Futures contracts for which there were no trades that day for a particular position are generally valued at the closing bid quotation as provided by a third-party pricing service on the market on which such futures contracts are primarily traded. Securities and other assets generally valued on the basis of information from a third-party pricing service may also be valued at a broker/dealer bid quotation. Values obtained from third-party pricing services can utilize both transaction data and market information such as yield, quality, coupon rate, maturity, type of issue, trading characteristics, and other market data.

The Board of Trustees has delegated primary responsibility for determining or causing to be determined the value of the fund’s investments (including any fair valuation) to the adviser pursuant to valuation policies and procedures approved by the Board. If the adviser determines that reliable market quotations are not readily available, investments are valued at fair value as determined in good faith by the adviser in accordance with such procedures under the oversight of the Board of Trustees. Under the fund’s valuation policies and procedures, market quotations are not considered to be readily available for most types of debt instruments and floating rate loans and many types of derivatives. These investments are generally valued at fair value based on information from third-party pricing services. In addition, investments may be valued at fair value if the adviser determines that an investment’s value has been materially affected by events occurring after the close of the exchange or market on which the investment is principally traded (such as foreign exchange or market) and prior to the determination of the fund’s net asset value, or after the halting of trading of a specific security where trading does not resume prior to the close of the exchange or market on which the security is principally traded. The adviser generally relies on third-party pricing services or other information (such as the correlation with price movements of similar securities in the same or other markets; the type, cost and investment characteristics of the security; the business and financial condition of the issuer; and trading and other market data) to assist in determining whether to fair value and at what value to fair value an investment. The value of an investment for purposes of calculating the fund’s net asset value can differ depending on the source and method used to determine value. When fair valuation is used, the value of an investment used to determine the fund’s net asset value may differ from quoted or published prices for the same investment. There can be no assurance that the fund could obtain the fair value assigned to an investment if it were to sell the investment at the same time at which the fund determines its net asset value per share.

Various inputs are used in determining the value of the fund’s assets or liabilities carried at market value. These inputs are categorized into three broad levels. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, an investment’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The fund’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the investment. Level 1 includes unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 includes other significant observable market-based inputs (including quoted prices for similar securities, interest rates, prepayment speed, and credit risk). Level 3 includes 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. The following is a summary of the levels used as of August 31, 2009 in valuing the fund’s assets or liabilities carried at market value:

Investments at Value	Level 1			Level 2		Level 3		Total
Municipal Bonds	$	—		$	182,985,054	$	—	$	182,985,054
Residential Mortgage-Backed Securities		—			422,586		—		422,586
Total Investments	$	—		$	183,407,640	$	—	$	183,407,640
Other Financial Instruments
Futures	$	(146,515	)	$	—	$	—	$	(146,515	)

For further information regarding security characteristics, see the Portfolio of Investments.

14

MFS High Yield Municipal Trust

Supplemental Information (Unaudited) 8/31/09 - continued

(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	$	201,111,342
Gross unrealized appreciation	$	7,193,816
Gross unrealized depreciation		(24,897,518	)
Net unrealized appreciation (depreciation)	$	(17,703,702	)

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

(3) Derivative Contracts at 8/31/09

Futures Contracts Outstanding at 8/31/09

Description	Currency	Contracts	Value	Expiration Date	Unrealized Appreciation (Depreciation)
Liability Derivatives
Interest Rate Futures
U.S. Treasury Note 10 yr (Short)	USD	238	27,898,063	Dec-09	$	(140,286	)
U.S. Treasury Note 30 yr (Short)	USD	41	4,909,750	Dec-09		(6,229	)
					$	(146,515	)

At August 31, 2009, the fund had sufficient cash and/or other liquid securities to cover any commitments under these derivative contracts.

15

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)*	MARIA F. DWYER
	Maria F. Dwyer, President

Date: October 16, 2009

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)*	MARIA F. DWYER
	Maria F. Dwyer, President (Principal Executive Officer)

Date: October 16, 2009

By (Signature and Title)*	JOHN M. CORCORAN
	John M. Corcoran, Treasurer (Principal Financial Officer and Accounting Officer)

Date: October 16, 2009

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

EX-99.CERT

EX-99.CERT

MFS HIGH YIELD MUNICIPAL TRUST

CERTIFICATION

I, John M. Corcoran, certify that:

1. I have reviewed this report on Form N-Q of MFS High Yield Municipal Trust;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the schedules of investments included in this report fairly present in all material respects the investments of the registrant as of the end of the fiscal quarter for which the report is filed;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

a. Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b. Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c. Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report, based on such evaluation; and

d. Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a. All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

b. Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: October 16, 2009	JOHN M. CORCORAN
	John M. Corcoran Treasurer (Principal Financial Officer and Accounting Officer)

EX-99.CERT

MFS HIGH YIELD MUNICIPAL TRUST

CERTIFICATION

I, Maria F. Dwyer, certify that:

1. I have reviewed this report on Form N-Q of MFS High Yield Municipal Trust;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the schedules of investments included in this report fairly present in all material respects the investments of the registrant as of the end of the fiscal quarter for which the report is filed;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

a. Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b. Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c. Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report, based on such evaluation; and

d. Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a. All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

b. Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: October 16, 2009	MARIA F. DWYER
	Maria F. Dwyer President (Principal Executive Officer)