Quarterly Report

December 31, 2020

MFS^® Tennessee
Municipal Bond Fund

MTN-Q3

Portfolio of Investments

12/31/20 (unaudited)

The Portfolio of Investments is a complete list of all securities owned by your fund. It is categorized by broad-based asset classes.

Issuer		Shares/Par	Value ($)
Municipal Bonds – 98.6%
Airport Revenue – 7.1%
Memphis-Shelby County, TN, Airport Authority Facilities Rev., 5%, 7/01/2037	$	1,000,000	$1,220,490
Memphis-Shelby County, TN, Airport Authority Facilities Rev., “A”, 4%, 7/01/2038		1,000,000	1,194,820
Memphis-Shelby County, TN, Airport Authority Facilities Rev., “D”, 5%, 7/01/2025		1,000,000	1,021,150
Metropolitan Government of Nashville, TN, Airport Authority Improvement Rev., “B”, 5%, 7/01/2035		1,100,000	1,263,999
Metropolitan Nashville Airport Authority, TN, Airport Rev., “B”, 5%, 7/01/2049		1,000,000	1,240,950
Metropolitan Nashville Airport Authority, TN, Airport Rev., “B”, 5%, 7/01/2054		1,000,000	1,234,790
			$7,176,199
General Obligations - General Purpose – 12.3%
Bedford County, TN, General Obligation Refunding Rev., BAM, 5%, 4/01/2023	$	1,190,000	$1,315,747
Bridgeview, IL, Stadium and Redevelopment Projects, AAC, 5.14%, 12/01/2036		245,000	239,208
Chicago, IL, General Obligation (Neighborhood Alive 21 Program), “B”, 5.5%, 1/01/2037		45,000	49,387
Chicago, IL, General Obligation Refunding Project, “A”, 5.25%, 1/01/2030		30,000	32,286
Chicago, IL, General Obligation, “A”, 5%, 1/01/2025		145,000	160,155
Chicago, IL, General Obligation, “A”, 5%, 1/01/2026		40,000	44,848
Chicago, IL, General Obligation, “A”, 5%, 1/01/2027		45,000	51,035
Chicago, IL, General Obligation, “A”, 5.25%, 1/01/2033		175,000	187,201
Commonwealth of Puerto Rico, General Obligation, “A”, 8%, 7/01/2035 (a)(d)		1,045,000	715,825
Commonwealth of Puerto Rico, Public Improvement, “A-4”, AGM, 5%, 7/01/2031		90,000	90,170
Jackson, TN, 5%, 6/01/2031		1,000,000	1,319,690
Memphis, TN, General Improvement, 4%, 6/01/2041		1,000,000	1,146,020
Memphis, TN, General Improvement, “B”, 5%, 4/01/2031		1,000,000	1,142,910
Memphis, TN, General Improvement, “B”, 5%, 4/01/2034		1,025,000	1,163,324
Metropolitan Government of Nashville & Davidson County, TN, 5%, 7/01/2021		1,500,000	1,503,240
Pigeon Forge, TN, Industrial Development Board, Public Facilities, 5%, 6/01/2034		1,000,000	1,016,080
Puerto Rico Public Buildings Authority Government Facilities Rev., “M-2”, AAC, 10%, 7/01/2035		190,000	200,349
State of Illinois, 5.5%, 5/01/2039		150,000	181,506
State of Illinois, “A”, 4%, 12/01/2033		20,000	21,479
State of New Jersey, COVID-19 General Obligation, “A”, 4%, 6/01/2032		255,000	317,830
State of Tennessee, “A”, 5%, 10/01/2029 (Prerefunded 10/01/2021)		1,500,000	1,553,475
			$12,451,765
General Obligations - Schools – 2.8%
Berks County, PA, Reading School District, AGM, 5%, 3/01/2036	$	25,000	$30,341
Williamson County, TN, School District, 5%, 4/01/2026		740,000	920,390
Wilson County, TN, Tenth Special School District, Limited Obligation, 4%, 4/01/2037		460,000	554,093
Wilson County, TN, Tenth Special School District, Limited Obligation, 4%, 4/01/2038		460,000	552,653
Wilson County, TN, Tenth Special School District, Limited Obligation, 4%, 4/01/2039		605,000	725,117
			$2,782,594
Healthcare Revenue - Hospitals – 16.5%
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (Catholic Health Initiatives), “A”, 5%, 10/01/2044	$	1,000,000	$1,090,180
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (Catholic Health Initiatives), “A”, 5.25%, 1/01/2045 (Prerefunded 1/01/2023)		500,000	548,935
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (CommonSpirit Health), “A-2”, 5%, 8/01/2044		500,000	612,655
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (CommonSpirit Health), “A-2”, 5%, 8/01/2049		1,000,000	1,213,520
Doylestown, PA, Hospital Rev., “A”, 4%, 7/01/2045		10,000	10,670
Greenville, TN, Health and Educational Facilities Board Hospital Rev. (Ballad Health), “A”, 4%, 7/01/2040		1,000,000	1,119,710
Jackson, TN, Hospital Refunding Rev. (Jackson-Madison County General Hospital), 4%, 4/01/2041		425,000	459,659
Jackson, TN, Hospital Rev. (Jackson-Madison County General Hospital), 5%, 4/01/2028		1,500,000	1,742,580
Jackson, TN, Hospital Rev. (Jackson-Madison County General Hospital), “A”, 5%, 4/01/2041		1,000,000	1,227,430
Knox County, TN, Health, Educational & Housing Facility Board Hospital Rev. (Covenant Health), “A”, 5%, 1/01/2033		1,000,000	1,198,240
Knox County, TN, Health, Educational & Housing Facility Board Hospital Rev. (East Tennessee Children's Hospital), 5%, 11/15/2038		1,000,000	1,244,310
Knox County, TN, Health, Educational & Housing Facility Board Rev. (University Health Systems, Inc.), 5%, 4/01/2036		750,000	878,812
Knox County, TN, Health, Educational & Housing Facility Board Rev. (University Health Systems, Inc.), 5%, 9/01/2036		1,000,000	1,158,380

1

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Healthcare Revenue - Hospitals – continued
Metropolitan Government of Nashville & Davidson County, TN, Health & Educational Facilities Board Rev. (Vanderbilt University Medical Center), “A”, 4%, 7/01/2047	$	1,500,000	$1,668,255
Miami-Dade County, FL, Health Facilities Authority Hospital Rev., Unrefunded Balance, 6%, 8/01/2030		25,000	25,090
New Jersey Health Care Facilities, Financing Authority Rev. (University Hospital), “A”, AGM, 5%, 7/01/2046		100,000	112,477
Shelby County, TN, Health, Educational & Housing Facility Board Rev. (Methodist Healthcare), “A”, 5%, 5/01/2035		1,500,000	1,820,460
Spartanburg County, SC, Regional Health Services District Hospital Rev., “A”, 4%, 4/15/2043		420,000	465,902
			$16,597,265
Healthcare Revenue - Long Term Care – 2.6%
Metropolitan Government of Nashville & Davidson County, TN, Health & Educational Facilities Board Rev. (Blakeford at Green Hills), 5%, 7/01/2037	$	1,000,000	$1,027,140
Metropolitan Government of Nashville & Davidson County, TN, Health & Educational Facilities Board Rev. (Blakeford at Green Hills), “A”, 4%, 11/01/2045		1,000,000	1,013,680
Shelby County, TN, Health, Educational & Housing Facility Board, Residential Care Facility Mortgage Rev. (Village at Germantown), 5.25%, 12/01/2049		550,000	583,182
			$2,624,002
Industrial Revenue - Other – 0.6%
Port Beaumont, TX, Navigation District Facility Rev. (Jefferson Gulf Coast Energy Project), “A”, 4%, 1/01/2050 (n)	$	220,000	$221,452
Tuscaloosa County, AL, Industrial Development Authority, Gulf Opportunity Zone (Hunt Refining Project), “A”, 5.25%, 5/01/2044 (n)		310,000	353,664
			$575,116
Miscellaneous Revenue - Other – 2.9%
Metropolitan Government of Nashville & Davidson County, TN, Sports Authority Rev., Public Improvement, “A”, 5%, 8/01/2023	$	1,205,000	$1,327,717
Metropolitan Nashville Airport Authority, Special Facilities Rev. (Aero Nashville LLC Project), 5.2%, 7/01/2026		535,000	535,385
New York Liberty Development Corp., Liberty Rev. (7 World Trade Center Project), 5%, 9/15/2040		980,000	1,027,187
			$2,890,289
Sales & Excise Tax Revenue – 3.6%
Guam Government Business Privilege Tax Rev., “A”, 5.25%, 1/01/2036	$	300,000	$310,185
Guam Government Business Privilege Tax Rev., “D”, 5%, 11/15/2031		270,000	308,399
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2026		40,000	47,536
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2027		80,000	97,314
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2028		75,000	93,027
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2029		20,000	25,284
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2030		35,000	44,982
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2036		35,000	43,891
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2037		50,000	62,718
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 4%, 1/01/2040		50,000	56,410
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-1”, 4.55%, 7/01/2040		23,000	25,245
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-1”, 5%, 7/01/2058		856,000	953,926
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.329%, 7/01/2040		226,000	244,903
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.329%, 7/01/2040		76,000	82,303
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.536%, 7/01/2053		1,000	1,085
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.784%, 7/01/2058		39,000	42,878
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2024		3,000	2,830
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2027		41,000	36,504
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2029		7,000	5,945
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2031		380,000	295,632
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2033		363,000	259,919
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2046		1,787,000	552,880
			$3,593,796
Secondary Schools – 0.4%
District of Columbia Rev. (Rocketship D.C.), “A”, 5%, 6/01/2049 (n)	$	250,000	$265,445
North Texas Education Finance Corp., Education Rev. (Uplift Education), “A”, 5.125%, 12/01/2042 (Prerefunded 6/01/2022)		130,000	138,887
			$404,332

2

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Single Family Housing - Local – 0.5%
Montgomery County, MD, Housing Opportunities Commission Program Rev., “A”, 4%, 7/01/2049	$	480,000	$540,038
Single Family Housing - State – 8.1%
Connecticut Housing Finance Authority Rev. (Housing Mortgage Finance Program), “D-1”, GNMA, 4%, 11/15/2047	$	390,000	$422,721
Iowa Finance Authority, Single Family Mortgage Rev., “A”, GNMA, 4%, 7/01/2047		390,000	422,331
Maryland Community Development Administration, Department of Housing & Community Development Housing Rev., “A”, 4.25%, 9/01/2049		445,000	497,421
South Carolina Housing Finance & Development Authority Mortgage Rev., “A”, 4%, 7/01/2050		1,080,000	1,233,878
Tennessee Housing Development Agency, Residential Finance Program Rev., “1”, 3.75%, 7/01/2039		1,485,000	1,665,725
Tennessee Housing Development Agency, Residential Finance Program Rev., “1”, 4.25%, 1/01/2050		115,000	128,350
Tennessee Housing Development Agency, Residential Finance Program Rev., “3”, 3.85%, 7/01/2043		945,000	1,024,342
Tennessee Housing Development Agency, Residential Finance Program Rev., “3”, 3.75%, 1/01/2050		950,000	1,068,114
Tennessee Housing Development Agency, Residential Finance Program Rev., “4”, 2.9%, 7/01/2039		225,000	240,869
Tennessee Housing Development Agency, Residential Finance Program Rev., “4”, 4%, 7/01/2043		1,115,000	1,248,733
Tennessee Housing Development Agency, Residential Finance Program Rev., “4”, 3.05%, 7/01/2044		240,000	254,347
			$8,206,831
State & Local Agencies – 5.5%
Delaware Valley, PA, Regional Finance Authority, “C”, FLR, 0.901% (LIBOR - 3mo. + 0.75%), 6/01/2037	$	795,000	$724,825
Maryland Stadium Authority Rev., Baltimore City Public Schools Construction and Revitalization Program, “A”, 5%, 5/01/2047 (Prerefunded 5/01/2028)		135,000	178,396
Maryland Stadium Authority Rev., Baltimore City Public Schools Construction and Revitalization Program, “A”, 5%, 5/01/2047		250,000	305,675
New Jersey Economic Development Authority Rev., School Facilities Construction, “AAA”, 5%, 6/15/2026		95,000	113,758
New Jersey Economic Development Authority Rev., School Facilities Construction, “LLL”, 5%, 6/15/2039		220,000	268,081
New Jersey Economic Development Authority Rev., School Facilities Construction, “LLL”, 5%, 6/15/2044		365,000	438,785
Orangeburg County, SC, Facilities Corp. Installment Purchase Rev. (Detention Center Project), 4%, 12/01/2042		335,000	375,605
Pennsylvania Public School Building Authority, School Lease Rev. (School District of Philadelphia Project), “A”, AGM, 5%, 6/01/2033		665,000	805,687
Tennessee School Board Authority, Higher Education Facilities Second Program, “A”, 5%, 11/01/2043		1,000,000	1,071,420
Tennessee School Board Authority, Higher Education Facilities Second Program, “A”, 5%, 11/01/2045		1,000,000	1,291,210
			$5,573,442
Student Loan Revenue – 0.2%
Iowa Student Loan Liquidity Corp. Rev., “B”, 3%, 12/01/2039	$	45,000	$46,049
Iowa Student Loan Liquidity Corp. Rev., “B”, 3.5%, 12/01/2044		115,000	116,791
			$162,840
Tax - Other – 2.3%
Birmingham-Jefferson, AL, Civic Center Authority, “B”, 5%, 7/01/2043	$	495,000	$545,500
Guam Government Ltd. Obligation Rev., “A”, 5%, 12/01/2035		105,000	121,655
Guam Government Ltd. Obligation Rev., “A”, 5%, 12/01/2036		60,000	69,351
Guam Government Ltd. Obligation Rev., “A”, 5%, 12/01/2046		175,000	198,681
Memphis-Shelby County, TN, Economic Development Growth Engine Industrial Development Board, Senior Tax Rev. (Graceland Project), “A”, 4.75%, 7/01/2027		300,000	294,876
Memphis-Shelby County, TN, Economic Development Growth Engine Industrial Development Board, Senior Tax Rev. (Graceland Project), “A”, 5.5%, 7/01/2037		100,000	98,083
Puerto Rico Convention Center District Authority, Hotel Occupancy Tax Rev., “A”, AAC, 5%, 7/01/2031		230,000	232,686
Puerto Rico Infrastructure Financing Authority Special Tax Rev., “C”, AAC, 5.5%, 7/01/2024		260,000	281,778
Puerto Rico Infrastructure Financing Authority Special Tax Rev., “C”, AAC, 5.5%, 7/01/2025		25,000	27,442
Puerto Rico Infrastructure Financing Authority Special Tax Rev., “C”, AAC, 5.5%, 7/01/2026		415,000	459,463
			$2,329,515
Tax Assessment – 0.5%
Nashville, TN, Metropolitan Development and Housing Agency Rev. (Fifth + Broadway Development), 5.125%, 6/01/2036	$	500,000	$539,105
Tobacco – 1.1%
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020A-2, “1”, 5%, 6/01/2036	$	70,000	$92,303
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020A-2, “1”, 4%, 6/01/2048		110,000	125,234
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020B-2, “2”, 5%, 6/01/2055		270,000	305,448

3

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Tobacco – continued
Illinois Railsplitter Tobacco Settlement Authority Rev., 6%, 6/01/2028 (Prerefunded 6/01/2021)	$	200,000	$204,742
Virgin Islands Tobacco Settlement Financing Corp., 5%, 5/15/2031		320,000	320,698
			$1,048,425
Toll Roads – 0.5%
Virginia Small Business Financing Authority Rev. (Elizabeth River Crossings Opco LLC Project), 6%, 1/01/2037	$	165,000	$175,840
Virginia Small Business Financing Authority Rev. (Elizabeth River Crossings Opco LLC Project), 5.5%, 1/01/2042		320,000	335,133
			$510,973
Transportation - Special Tax – 4.0%
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “CC”, AGM, 5.5%, 7/01/2028	$	745,000	$882,698
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “J”, NATL, 5%, 7/01/2029		15,000	15,175
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “L”, AAC, 5.25%, 7/01/2038		765,000	835,097
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “L”, NATL, 5.25%, 7/01/2035		270,000	287,734
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “N”, AAC, 5.5%, 7/01/2029		665,000	745,133
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “N”, AAC, 5.25%, 7/01/2031		45,000	49,478
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “N”, NATL, 5.25%, 7/01/2032		70,000	74,724
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “N”, NATL, 5.25%, 7/01/2033		90,000	96,234
Metropolitan Transportation Authority Rev., NY, Anticipation Note, “B-2”, 5%, 5/15/2021		340,000	343,567
Metropolitan Transportation Authority Rev., NY, Anticipation Note, “D-1”, 5%, 9/01/2022		250,000	261,965
New Jersey Transportation Trust Fund Authority, Federal Highway Reimbursement Rev., “A-1”, 5%, 6/15/2027		200,000	238,422
New Jersey Transportation Trust Fund Authority, Transportation System, “A”, 5.25%, 12/15/2021		55,000	57,496
New Jersey Transportation Trust Fund Authority, Transportation System, “A”, 5%, 12/15/2039		65,000	79,131
New Jersey Transportation Trust Fund Authority, Transportation System, “BB”, 5%, 6/15/2044		70,000	82,928
			$4,049,782
Universities - Colleges – 7.8%
Franklin County, TN, Health & Educational Facilities Board Rev. (University of the South), 5%, 9/01/2030	$	375,000	$402,409
Metropolitan Government of Nashville & Davidson County, TN, Health & Educational Facilities Board Rev. (Lipscomb University Project), “A”, 5%, 10/01/2041		1,000,000	1,087,210
Metropolitan Government of Nashville & Davidson County, TN, Health & Educational Facilities Board Rev. (Lipscomb University Project), “A”, 4%, 10/01/2049		1,000,000	1,031,950
Metropolitan Government of Nashville & Davidson County, TN, Health & Educational Facilities Board Rev., Refunding & Improvement (Trevecca Nazarene University Project), 5%, 10/01/2039		200,000	223,688
Metropolitan Government of Nashville & Davidson County, TN, Health & Educational Facilities Board Rev., Refunding & Improvement (Trevecca Nazarene University Project), 5%, 10/01/2048		1,800,000	1,984,050
Pinellas County, FL, Educational Facilities Authority Rev. (Barry University), 6%, 10/01/2041		120,000	122,596
Puerto Rico Industrial, Tourist, Educational, Medical & Environmental Control Facilities Financing Authority, Higher Education Rev. (Ana G. Mendez University System Project), 5.375%, 12/01/2021		5,000	4,991
Shelby County, TN, Health, Educational & Housing Facility Board, Educational Facilities Rev. (Rhodes College), 4%, 8/01/2035		605,000	698,999
Shelby County, TN, Health, Educational & Housing Facility Board, Educational Facilities Rev. (Rhodes College), 4%, 8/01/2040		1,120,000	1,279,174
Shelby County, TN, Health, Educational & Housing Facility Board, Educational Facilities Rev. (Rhodes College), 5.5%, 8/01/2040 (Prerefunded 8/01/2021)		1,000,000	1,029,880
University of Puerto Rico Rev., “P”, NATL, 5%, 6/01/2025		15,000	15,175
			$7,880,122
Universities - Dormitories – 0.5%
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (CDFI Phase I LLC, University of Tennessee at Chattanooga), 5%, 10/01/2035	$	500,000	$518,520
Utilities - Cogeneration – 0.2%
Puerto Rico Industrial, Tourist, Educational, Medical & Environmental Control Facilities Financing Authority Rev. (Cogeneration Facilities - AES Puerto Rico Project), 9.12%, 6/01/2022	$	225,000	$230,625
Utilities - Municipal Owned – 5.0%
Memphis, TN, Electric Systems Rev., 5%, 12/01/2034 (Prerefunded 12/01/2024)	$	1,000,000	$1,183,640
Memphis, TN, Electric Systems Rev., “A”, 5%, 12/01/2033		1,000,000	1,366,010
Metropolitan Government of Nashville & Davidson County, TN, Electric System Rev., “A”, 5%, 5/15/2037		1,000,000	1,234,060
Puerto Rico Electric Power Authority Rev., “A”, 5%, 7/01/2029 (a)(d)		260,000	209,950

4

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Utilities - Municipal Owned – continued
Puerto Rico Electric Power Authority Rev., “A”, 5%, 7/01/2042 (a)(d)	$	40,000	$32,300
Puerto Rico Electric Power Authority Rev., “AAA”, 5.25%, 7/01/2021 (a)(d)		20,000	16,200
Puerto Rico Electric Power Authority Rev., “AAA”, 5.25%, 7/01/2030 (a)(d)		10,000	8,100
Puerto Rico Electric Power Authority Rev., “CCC”, 5.25%, 7/01/2027 (a)(d)		90,000	72,900
Puerto Rico Electric Power Authority Rev., “DDD”, 5%, 7/01/2020 (a)(d)		10,000	7,950
Puerto Rico Electric Power Authority Rev., “DDD”, 5%, 7/01/2021 (a)(d)		100,000	80,750
Puerto Rico Electric Power Authority Rev., “DDD”, 5%, 7/01/2022 (a)(d)		165,000	133,237
Puerto Rico Electric Power Authority Rev., “EEE”, 6.05%, 7/01/2032 (a)(d)		50,000	40,250
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2021 (a)(d)		40,000	32,300
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2023 (a)(d)		40,000	32,300
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2027 (a)(d)		10,000	8,075
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2037 (a)(d)		130,000	104,975
Puerto Rico Electric Power Authority Rev., “V”, NATL, 5.25%, 7/01/2033		65,000	69,503
Puerto Rico Electric Power Authority Rev., “VV”, NATL, 5.25%, 7/01/2032		145,000	154,785
Puerto Rico Electric Power Authority Rev., “VV”, NATL, 5.25%, 7/01/2034		10,000	10,696
Puerto Rico Electric Power Authority Rev., “WW”, 5.375%, 7/01/2022 (a)(d)		10,000	8,112
Puerto Rico Electric Power Authority Rev., “WW”, 5.25%, 7/01/2025 (a)(d)		15,000	12,150
Puerto Rico Electric Power Authority Rev., “ZZ”, 5%, 7/01/2018 (a)(d)		65,000	51,675
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2023 (a)(d)		70,000	56,700
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2024 (a)(d)		20,000	16,200
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2026 (a)(d)		60,000	48,600
			$4,991,418
Utilities - Other – 2.0%
Central Plains Energy Project, NE, Gas Project Rev. (Project No. 3), “A”, 5%, 9/01/2036	$	70,000	$98,662
Tennessee Energy Acquisition Corp., Gas Rev., “A”, 5.25%, 9/01/2021		225,000	232,227
Tennessee Energy Acquisition Corp., Gas Rev., “A”, 5.25%, 9/01/2022		115,000	124,017
Tennessee Energy Acquisition Corp., Gas Rev., “A”, 5.25%, 9/01/2023		110,000	123,447
Tennessee Energy Acquisition Corp., Gas Rev., “A”, 5.25%, 9/01/2026		1,200,000	1,473,636
			$2,051,989
Water & Sewer Utility Revenue – 11.6%
Clarksville, TN, Water, Sewer & Gas Rev., 5%, 2/01/2029 (Prerefunded 2/01/2023)	$	1,000,000	$1,098,990
Clarksville, TN, Water, Sewer & Gas Rev., 4%, 2/01/2038		500,000	589,210
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 7/01/2036		65,000	75,662
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 7/01/2036		110,000	130,769
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 7/01/2037		135,000	160,115
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 7/01/2040		380,000	448,195
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 1/01/2046		300,000	342,972
Guam Waterworks Authority Rev. (Water and Wastewater System), “A”, 5%, 1/01/2050		120,000	148,804
Knox County, TN, Hallsdale-Powell Utility District, Waterworks & Sewer Rev., 4%, 4/01/2035		1,000,000	1,207,930
Memphis, TN, Sanitary Sewerage Systems Rev., “B”, 5%, 10/01/2039		1,000,000	1,345,100
Memphis, TN, Sanitary Sewerage Systems Rev., “B”, 5%, 10/01/2040		1,000,000	1,341,420
Memphis, TN, Storm Water System Rev., 5%, 10/01/2039		1,410,000	1,758,002
Metropolitan Government of Nashville & Davidson County, TN, Water & Sewer Rev., 5%, 7/01/2032		2,000,000	2,213,460
Michigan Finance Authority Local Government Loan Program Rev. (Detroit Water and Sewerage Department Sewage Disposal System Rev. Refunding Second Lien Local Project), “C-7”, NATL, 5%, 7/01/2032		30,000	34,143
Michigan Finance Authority Local Government Loan Program Rev. (Detroit Water and Sewerage Department Water Supply System Rev. Refunding Second Lien Local Project), “D-6”, NATL, 5%, 7/01/2036		35,000	39,614
Michigan Finance Authority Local Government Loan Program Rev. (Detroit Water and Sewerage Department Water Supply System Rev. Refunding Senior Lien Local Project), “D-1”, AGM, 5%, 7/01/2035		20,000	22,732
Michigan Finance Authority Local Government Loan Program Rev. (Detroit Water and Sewerage Department Water Supply System Rev. Refunding Senior Lien Local Project), “D-1”, AGM, 5%, 7/01/2037		45,000	50,966
Mississippi Development Bank Special Obligation (Jackson Water and Sewer System Rev. Bond Project), AGM, 6.875%, 12/01/2040		65,000	74,980
Wilson County, TN, West Wilson Utility District Waterworks Rev., 5%, 6/01/2030		550,000	657,778
			$11,740,842
Total Municipal Bonds			$99,469,825

5

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Bonds – 0.1%
Consumer Services – 0.1%
Toll Road Investors Partnership II LP, Capital Appreciation, NATL, 0%, 2/15/2043 (n)	$	400,000	$115,209
Investment Companies (h) – 0.1%
Money Market Funds – 0.1%
MFS Institutional Money Market Portfolio, 0.1% (v)		113,314	$113,313
Other Assets, Less Liabilities – 1.2%			1,257,553
Net Assets – 100.0%			$100,955,900

(a)	Non-income producing security.
(d)	In default.
(h)	An affiliated issuer, which may be considered one in which the fund owns 5% or more of the outstanding voting securities, or a company which is under common control. At period end, the aggregate values of the fund's investments in affiliated issuers and in unaffiliated issuers were $113,313 and $99,585,034, respectively.
(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 $955,770, representing 0.9% of net assets.
(v)	Affiliated issuer that is available only to investment companies managed by MFS. The rate quoted for the MFS Institutional Money Market Portfolio is the annualized seven-day yield of the fund at period end.

The following abbreviations are used in this report and are defined:
AAC	Ambac Assurance Corp.
AGM	Assured Guaranty Municipal
BAM	Build America Mutual
FLR	Floating Rate. Interest rate resets periodically based on the parenthetically disclosed reference rate plus a spread (if any). The period-end rate reported may not be the current rate. All reference rates are USD unless otherwise noted.
GNMA	Government National Mortgage Assn.
LIBOR	London Interbank Offered Rate
NATL	National Public Finance Guarantee Corp.

Derivative Contracts at 12/31/20
Futures Contracts
Description	Long/ Short	Currency	Contracts	Notional Amount	Expiration Date	Value/Unrealized Appreciation (Depreciation)
Asset Derivatives
Interest Rate Futures
U.S. Treasury Bond	Short	USD	5	$865,938	March – 2021	$5,372

At December 31, 2020, the fund had cash collateral of $21,000 to cover any collateral or margin obligations for certain derivative contracts.

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

6

Supplemental Information

12/31/20 (unaudited)

The fund is an investment company and accordingly follows the investment company accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 Financial Services - Investment Companies.

(1) Investment Valuations

Debt instruments and floating rate loans, 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 may be valued at amortized cost, which approximates market value. Futures contracts are generally valued at last posted settlement price on their primary exchange as provided by a third-party pricing service. Futures contracts for which there were no trades that day for a particular position are generally valued at the closing bid quotation on their primary exchange as provided by a third-party pricing service. Open-end investment companies are generally valued at net asset value per share. 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. In determining values, 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 halt 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. 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, such as futures contracts. The following is a summary of the levels used as of December 31, 2020 in valuing the fund's assets or liabilities:

Financial Instruments	Level 1	Level 2	Level 3	Total
Municipal Bonds	$—	$99,469,825	$—	$99,469,825
U.S. Corporate Bonds	—	115,209	—	115,209
Mutual Funds	113,313	—	—	113,313
Total	$113,313	$99,585,034	$—	$99,698,347
Other Financial Instruments
Futures Contracts – Assets	$5,372	$—	$—	$5,372

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

(2) Investments in Affiliated Issuers

An affiliated issuer may be considered one in which the fund owns 5% or more of the outstanding voting securities, or a company which is under common control. For the purposes of this report, the following were affiliated issuers:

Affiliated Issuers	Beginning Value	Purchases	Sales Proceeds	Realized Gain (Loss)	Change in Unrealized Appreciation or Depreciation	Ending Value
MFS Institutional Money Market Portfolio	$1,471,518	$20,707,189	$22,064,967	$(534)	$107	$113,313

7

Supplemental Information (unaudited) – continued

Affiliated Issuers	Dividend Income	Capital Gain Distributions
MFS Institutional Money Market Portfolio	$2,723	$—

(3) Jurisdiction Weightings

Jurisdiction weighting percentages based on net assets, as of December 31, 2020, are as follows:

Tennessee	73.9%
Puerto Rico	9.0%
Guam	2.3%
South Carolina	2.1%
Illinois	1.7%
New Jersey	1.7%
New York	1.6%
Pennsylvania	1.6%
Maryland	1.5%
Alabama	0.9%
Iowa	0.6%
Virginia	0.6%
Ohio	0.5%
Connecticut	0.4%
Texas	0.4%
U.S. Virgin Islands	0.3%
Washington DC	0.3%
Florida	0.1%
Michigan	0.1%
Mississippi	0.1%
Nebraska	0.1%
U.S. Treasury Securities	(0.9%)

The jurisdiction weighting percentages include both accrued interest amounts and equivalent exposure from any derivatives holdings, if applicable.

(4) Impacts of COVID-19

The pandemic related to the global spread of novel coronavirus disease (COVID-19), which was first detected in December 2019, has resulted in significant disruptions to global business activity and the global economy, as well as the economies of individual countries, the financial performance of individual companies and sectors, and the securities and commodities markets in general. This pandemic, the full effects of which are still unknown, has resulted in substantial market volatility and may have adversely impacted the prices and liquidity of the fund's investments and the fund's performance.

8