Quarterly Report

December 31, 2023

MFS^® Maryland
Municipal Bond Fund

MMD-Q3

Portfolio of Investments

12/31/23 (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 – 95.6%
Airport Revenue – 2.1%
Denver, CO, City & County Airport System Rev., “A”, 4.125%, 11/15/2047	$	70,000	$69,318
Denver, CO, City & County Airport System Rev., “A”, 4.125%, 11/15/2053		65,000	62,730
Metropolitan Washington, D.C., Airport Authority System Refunding Rev., “A”, 5%, 10/01/2025		1,525,000	1,567,181
New York Transportation Development Corp., Special Facilities Rev. (John F. Kennedy International Airport New Terminal One Project), AGM, 5.125%, 6/30/2060		655,000	686,971
			$2,386,200
General Obligations - General Purpose – 12.2%
Anne Arundel County, MD, General Obligation, Consolidated Improvement, 5%, 4/01/2033	$	1,895,000	$1,945,248
Anne Arundel County, MD, General Obligation, Consolidated Improvement, 5%, 10/01/2045		1,315,000	1,498,678
Baltimore County, MD, Metropolitan District (80th Issue), 4%, 3/01/2045		1,500,000	1,512,602
Bridgeview, IL, Stadium and Redevelopment Projects, Taxable, AAC, 5.14%, 12/01/2036		225,000	201,537
Cheverly, MD, Public Improvement, 4.5%, 11/01/2047		490,000	509,388
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, Capital Appreciation, Series 2022A, 0%, 7/01/2024		6,747	6,615
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, Capital Appreciation, Series 2022A, 0%, 7/01/2033		53,375	33,275
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, Series 2022A, 5.625%, 7/01/2029		45,031	48,839
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, Series 2022A, 5.75%, 7/01/2031		121,739	135,417
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, Series 2022A, 4%, 7/01/2033		41,476	40,609
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, Series 2022A, 4%, 7/01/2035		75,390	72,890
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, Series 2022A, 4%, 7/01/2037		31,997	30,548
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, Series 2022A, 4%, 7/01/2041		43,504	39,899
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, Series 2022A, 4%, 7/01/2046		150,243	133,817
Howard County, MD, Metropolitan District Project, “B”, 3%, 8/15/2051		1,155,000	929,266
Howard County, MD, Metropolitan District Project, “C”, 4%, 2/15/2048		1,500,000	1,507,012
Maryland Community Development Administration, Local Government Infrastructure, “A-2”, 4%, 6/01/2036		1,210,000	1,273,174
Maryland State & Local Facilities Loan, General Obligation Refunding, “A”, 5%, 8/01/2025		2,055,000	2,132,217
Montgomery County, MD, General Obligation, Consolidated Public Improvement, “A”, 5%, 8/01/2035		1,000,000	1,199,791
State of Illinois, General Obligation, 5.5%, 5/01/2039		160,000	177,145
State of Illinois, General Obligation, “C”, 4%, 10/01/2040		300,000	300,530
State of Illinois, General Obligation, “C”, 4%, 10/01/2041		190,000	189,327
Texas Cedar Port Navigation & Improvement District, Unlimited Tax, 4.5%, 9/01/2048		130,000	131,159
Texas Cedar Port Navigation & Improvement District, Unlimited Tax, 4.5%, 9/01/2052		50,000	50,258
			$14,099,241
General Obligations - Schools – 0.6%
Chicago, IL, Board of Education, Unlimited Tax General Obligation Dedicated Rev., “A”, 4%, 12/01/2047	$	325,000	$281,878
Orange County, CA, Anaheim Elementary School District, AGM, 4%, 8/01/2048		405,000	407,021
			$688,899
Healthcare Revenue - Hospitals – 17.6%
Doylestown, PA, Hospital Authority Rev., “A”, 4%, 7/01/2045 (Prerefunded 7/01/2029)	$	5,000	$5,356
Doylestown, PA, Hospital Authority Rev., “A”, 4%, 7/01/2045		10,000	7,441
Harris County, TX, Cultural Education Facilities Finance Corp., Hospital Rev. (Memorial Hermann Health System), “A”, 4.125%, 7/01/2052		540,000	518,079
Maryland Health & Higher Educational Facilities Authority Rev. (Adventist Healthcare), 5%, 1/01/2036		750,000	799,102
Maryland Health & Higher Educational Facilities Authority Rev. (Doctors Community Hospital), “A”, 5%, 7/01/2034		750,000	780,176
Maryland Health & Higher Educational Facilities Authority Rev. (Frederick Health System), 4%, 7/01/2045		1,000,000	970,648
Maryland Health & Higher Educational Facilities Authority Rev. (Greater Baltimore Medical Center), “A”, 4%, 7/01/2039		1,145,000	1,156,858
Maryland Health & Higher Educational Facilities Authority Rev. (Greater Baltimore Medical Center), “A”, 4%, 7/01/2041		1,000,000	1,001,740
Maryland Health & Higher Educational Facilities Authority Rev. (LifeBridge Health), 5%, 7/01/2028 (Prerefunded 7/01/2025)		750,000	775,101
Maryland Health & Higher Educational Facilities Authority Rev. (LifeBridge Health), 4%, 7/01/2042		1,000,000	1,003,196
Maryland Health & Higher Educational Facilities Authority Rev. (Medlantic/Helix Parent, Inc.), “A”, AGM, 5.25%, 8/15/2038		1,155,000	1,343,900
Maryland Health & Higher Educational Facilities Authority Rev. (MedStar Health), 5%, 8/15/2033		1,030,000	1,049,948
Maryland Health & Higher Educational Facilities Authority Rev. (MedStar Health), “A”, 5%, 8/15/2041		505,000	505,181
Maryland Health & Higher Educational Facilities Authority Rev. (MedStar Health), “A”, 5%, 5/15/2042		750,000	773,065
Maryland Health & Higher Educational Facilities Authority Rev. (Mercy Medical Center), “A”, 5%, 7/01/2032		600,000	619,940

1

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Healthcare Revenue - Hospitals – continued
Maryland Health & Higher Educational Facilities Authority Rev. (Meritus Medical Center), 5%, 7/01/2027	$	500,000	$511,276
Maryland Health & Higher Educational Facilities Authority Rev. (Peninsula Regional Health System), “A”, 5%, 7/01/2033		1,205,000	1,315,274
Maryland Health & Higher Educational Facilities Authority Rev. (Peninsula Regional Health System), “A”, 5%, 7/01/2035		500,000	544,570
Maryland Health & Higher Educational Facilities Authority Rev. (Trinity Health Credit Group), “MD”, 5%, 12/01/2046		1,000,000	1,030,979
Maryland Health & Higher Educational Facilities Authority Rev. (University of Maryland Medical System), “B”, 5%, 7/01/2034		1,000,000	1,060,231
Maryland Health & Higher Educational Facilities Authority Rev. (University of Maryland Medical System), “D”, 4%, 7/01/2048		1,250,000	1,214,289
Maryland Health & Higher Educational Facilities Authority Rev. (University of Pittsburgh Medical Center), “B”, 4%, 4/15/2045		995,000	988,497
Montgomery County, MD, Rev. (Trinity Health Credit Group), 5%, 12/01/2045		1,240,000	1,268,327
New York Dormitory Authority Rev. (Norwell Health Obligated Group), “A”, 4.25%, 5/01/2052		590,000	590,015
Spartanburg County, SC, Regional Health Services District Hospital Rev., “A”, 4%, 4/15/2043		635,000	623,429
			$20,456,618
Healthcare Revenue - Long Term Care – 3.2%
Baltimore County, MD, Rev. (Oak Crest Village, Inc.), 4%, 1/01/2045	$	1,000,000	$940,466
Baltimore County, MD, Rev. (Riderwood Village, Inc.), 4%, 1/01/2038		450,000	450,701
Howard County, MD, Retirement Community Rev. (Vantage House Facility), 5%, 4/01/2036		500,000	450,192
Maryland Health & Higher Educational Facilities Authority Rev. (Charlestown Community Project), “A”, 5%, 1/01/2045		500,000	509,629
Rockville, MD, Mayor & Council Economic Development Rev. (Ingleside at King Farm Project), “B”, 5%, 11/01/2042		350,000	306,152
Washington County, MD, County Commissioners Rev. (Diakon Lutheran Social Ministries Project), “B”, 5%, 1/01/2032		575,000	642,135
Westminster, MD, Refunding Rev. (Carroll Lutheran Village, Inc.), 5.125%, 7/01/2040		400,000	403,780
			$3,703,055
Healthcare Revenue - Other – 0.3%
Maryland Economic Development Corp., Economic Development Rev. (Lutheran World Relief Refugee), 5.25%, 4/01/2029	$	370,000	$370,197
Industrial Revenue - Paper – 0.1%
Valparaiso, IN, Exempt Facilities Rev. (Pratt Paper LLC Project), 7%, 1/01/2044	$	100,000	$100,195
Miscellaneous Revenue - Other – 2.4%
Baltimore, MD, Convention Center Hotel Rev., 5%, 9/01/2025	$	20,000	$20,094
Baltimore, MD, Convention Center Hotel Rev., 5%, 9/01/2034		85,000	86,368
Baltimore, MD, Convention Center Hotel Rev., 5%, 9/01/2042		70,000	67,331
Maryland Economic Development Corp., Air Cargo Obligated Group Rev. (AFCO Airport Real Estate Group), 4%, 7/01/2039		1,100,000	1,048,843
Matching Fund Special Purpose Securitization Corp., “A”, 5%, 10/01/2026		40,000	40,461
Montgomery County, MD, Transportation Fund Lease Authority Rev., “A”, 5%, 11/01/2036		415,000	426,789
New York Liberty Development Corp., Liberty Rev. (3 World Trade Center Project), “1”, 5%, 11/15/2044 (n)		240,000	237,837
New York, NY, Industrial Development Agency, Airport Facilities Rev. (Transportation Infrastructure Properties LLC), 5%, 7/01/2028		390,000	390,150
Pennsylvania Economic Development Financing Authority, Private Activity Rev. (PennDOT Major Bridges Package One Project), AGM, 5%, 12/31/2057		490,000	505,761
			$2,823,634
Multi-Family Housing Revenue – 8.7%
Howard County, MD, Housing Commission Rev. (Columbia Commons Apartments), “A”, 5%, 6/01/2044	$	500,000	$501,840
Howard County, MD, Housing Commission Rev. (Woodfield Oxford Square Apartments), 5%, 12/01/2037		750,000	792,563
Maryland Community Development Administration, Department of Housing & Community Development Housing Rev., “A”, FHA, 4%, 7/01/2048		500,000	453,618
Maryland Community Development Administration, Department of Housing & Community Development Housing Rev., “B”, 3.65%, 7/01/2049		505,000	460,960
Maryland Community Development Administration, Department of Housing & Community Development Housing Rev., “D”, 3.35%, 7/01/2049		1,765,000	1,518,867
Montgomery County, MD, Housing Opportunities Commission Multiple Purpose Rev., “C”, 5.5%, 1/01/2048		1,000,000	1,112,133
Montgomery County, MD, Housing Opportunities Commission Multiple Purpose Rev., “C”, 5.125%, 1/01/2053		500,000	538,889
Montgomery County, MD, Housing Opportunities Commission, Multi-Family Housing Development Rev., “A”, 4.85%, 7/01/2053		500,000	511,134
Montgomery County, MD, Housing Opportunities Commission, Multi-Family Housing Development Rev., “A-1”, FHA, 3.05%, 7/01/2044		1,000,000	822,975
Montgomery County, MD, Housing Opportunities Commission, Multi-Family Housing Development Rev., “C”, 5.125%, 7/01/2037		1,000,000	1,017,263
Montgomery County, MD, Housing Opportunities Commission, Multi-Family Housing Development Rev., “C”, 3.1%, 7/01/2036		1,065,000	973,672

2

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Multi-Family Housing Revenue – continued
National Finance Authority, NH, Municipal Certificates, “1-A”, 4.375%, 9/20/2036	$	282,419	$285,243
New York, NY, Housing Development Corp., Multi-Family Housing Rev. (Sustainable Development Bonds), “G”, FHA, 2.45%, 11/01/2045		765,000	555,300
Virginia Housing Development Authority Rental Housing, “F”, HUD Section 8, 5.15%, 11/01/2048		500,000	529,214
			$10,073,671
Parking – 1.2%
Maryland Health & Higher Educational Facilities Authority Rev. (Johns Hopkins Medical Institutions), AAC, 5%, 7/01/2034	$	1,385,000	$1,394,282
Port Revenue – 1.4%
Maryland Economic Development Corp. Rev. (Terminal Project), “A”, 5%, 6/01/2044	$	500,000	$518,875
Maryland Economic Development Corp. Rev. (Terminal Project), “A”, 5%, 6/01/2049		250,000	257,910
Maryland Economic Development Corp. Rev. (Transportation Facilities Project), “A”, 5%, 6/01/2031		650,000	690,294
New York Liberty Development Corp., Liberty Refunding Rev. (1 World Trade Center Project), 2.75%, 2/15/2044		190,000	151,270
			$1,618,349
Sales & Excise Tax Revenue – 2.7%
Guam Government Business Privilege Tax Refunding, “F”, 5%, 1/01/2030	$	5,000	$5,385
Guam Government Business Privilege Tax Refunding, “F”, 5%, 1/01/2031		10,000	10,843
Guam Government Business Privilege Tax Refunding, “F”, 4%, 1/01/2042		75,000	71,799
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-1”, 4.55%, 7/01/2040		21,000	21,102
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-1”, 4.75%, 7/01/2053		81,000	80,162
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-1”, 5%, 7/01/2058		1,817,000	1,823,340
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.329%, 7/01/2040		160,000	158,834
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.329%, 7/01/2040		75,000	74,454
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.784%, 7/01/2058		267,000	263,179
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2024		1,000	980
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2027		36,000	31,334
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2029		6,000	4,798
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2031		338,000	247,374
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2033		332,000	221,133
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2046		151,000	47,342
Wisconsin Public Finance Authority Limited Obligation Grant Rev. (American Dream at Meadowlands Project), “A”, 6.25%, 8/01/2027 (a)(d)(n)		120,000	93,600
			$3,155,659
Secondary Schools – 0.2%
District of Columbia Rev. (Rocketship D.C.), “A”, 5%, 6/01/2039 (n)	$	250,000	$236,364
Single Family Housing - Local – 0.9%
Montgomery County, MD, Housing Opportunities Commission, Single Family Mortgage Rev., “A”, FHA, 5.75%, 7/01/2054	$	1,000,000	$1,096,672
Single Family Housing - State – 7.7%
Maryland Community Development Administration, Department of Housing & Community Development Housing Rev., “B”, 2.1%, 9/01/2041	$	1,500,000	$1,097,758
Maryland Community Development Administration, Department of Housing & Community Development Residential Rev., “A”, GNMA, 4.45%, 9/01/2043		500,000	508,561
Maryland Community Development Administration, Department of Housing & Community Development Residential Rev., “A”, GNMA, 5.5%, 9/01/2053		1,000,000	1,082,607
Maryland Community Development Administration, Department of Housing & Community Development Residential Rev., “C”, 2.1%, 3/01/2033		250,000	219,296
Maryland Community Development Administration, Department of Housing & Community Development Residential Rev., “C”, 3%, 9/01/2051		940,000	911,511
Maryland Community Development Administration, Department of Housing & Community Development Residential Rev., “D”, 5.05%, 3/01/2047		1,000,000	1,037,904
Maryland Community Development Administration, Department of Housing & Community Development Residential Rev., “D”, 6%, 3/01/2053		985,000	1,063,500
Maryland Community Development Administration, Department of Housing & Community Development Residential Rev., “E”, GNMA, 5.1%, 3/01/2048		1,000,000	1,050,259

3

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Single Family Housing - State – continued
Maryland Community Development Administration, Department of Housing & Community Development Residential Rev., “E”, GNMA, 6.25%, 3/01/2054	$	1,000,000	$1,104,311
Maryland Community Development Administration, Department of Housing & Community Development Residential Rev., “C”, 3%, 9/01/2039		1,000,000	883,093
			$8,958,800
State & Local Agencies – 11.9%
Maryland Stadium Authority Rev., Baltimore City Public Schools Construction & Revitalization Program, 5%, 5/01/2041 (Prerefunded 5/01/2026)	$	500,000	$527,562
Maryland Stadium Authority Rev., Baltimore City Public Schools Construction & Revitalization Program, “A”, 5%, 5/01/2035		1,725,000	1,866,425
Maryland Stadium Authority Rev., Baltimore City Public Schools Construction & Revitalization Program, “A”, 5%, 5/01/2038		500,000	532,531
Maryland Stadium Authority Rev., Baltimore City Public Schools Construction & Revitalization Program, Capital Appreciation, “C”, 0%, 5/01/2054		2,000,000	498,418
Maryland Stadium Authority, Built to Learn Rev., 4%, 6/01/2046		1,405,000	1,412,766
Maryland Stadium Authority, Built to Learn Rev., “A”, 4%, 6/01/2036		1,000,000	1,056,095
Maryland Stadium Authority, Built to Learn Rev., “A”, 4%, 6/01/2041		1,500,000	1,535,791
Maryland Stadium Authority, Sport Entertainment Facilities Rev. (Hagerstown Project), “A”, 5.25%, 6/15/2052		1,000,000	1,111,222
Prince George's County, MD, COP (Suitland Public Infrastructure), 3%, 10/01/2038		1,000,000	923,768
Prince George's County, MD, COP (University of Maryland Capital Region Medical Center), 5%, 10/01/2037		1,000,000	1,088,611
Prince George's County, MD, COP (University of Maryland Capital Region Medical Center), 5%, 10/01/2048		1,500,000	1,572,971
Washington, D.C., Metropolitan Area Transit Authority Dedicated Rev. (Green Bonds - Climate Bond Certified), “A”, 5%, 7/15/2040		1,500,000	1,740,666
			$13,866,826
Student Loan Revenue – 0.5%
Iowa Student Loan Liquidity Corp. Rev., “C”, 3.5%, 12/01/2044	$	115,000	$96,184
New Jersey Higher Education Student Assistance Authority, Senior Student Loan Rev., “B”, 4%, 12/01/2041		490,000	483,880
			$580,064
Tax - Other – 2.0%
Chicago, IL, Board of Education, Dedicated Capital Improvement Tax Bond, 5%, 4/01/2045	$	85,000	$88,702
Chicago, IL, Board of Education, Dedicated Capital Improvement Tax Bond, 5.75%, 4/01/2048		225,000	246,061
New York, NY, Transitional Finance Authority Rev., “C-1”, 4%, 5/01/2045		850,000	853,106
St. Clair County, AL, Board of Education, Special Tax School Warrants (15 Mill Moody Tax), “A”, BAM, 4.125%, 2/01/2048		500,000	504,510
Triborough Bridge & Tunnel Authority Rev., NY, Payroll Mobility Tax (MTA Bridges and Tunnels), ”C-3“, 3%, 5/15/2051		600,000	485,246
Wisconsin Public Finance Authority Limited Obligation PILOT Rev. (American Dream at Meadowlands Project), 7%, 12/01/2050		100,000	93,156
			$2,270,781
Tax Assessment – 3.6%
Baltimore, MD, Special Obligation (East Baltimore Research Park Project), “A”, 5%, 9/01/2038	$	500,000	$503,377
Baltimore, MD, Special Obligation Rev. (Harbor Point Project), “B”, 3.875%, 6/01/2046 (n)		300,000	251,400
Brunswick, MD, Special Obligation Refunding (Brunswick Crossing Special Taxing District), 5%, 7/01/2036		500,000	508,848
Frederick County, MD, Limited Obligation (Jefferson Technology Park Project), “B”, 4.625%, 7/01/2043 (n)		250,000	243,882
Frederick County, MD, Limited Obligation (Oakdale-Lake Linganore Project), 3.75%, 7/01/2039		500,000	446,149
Frederick County, MD, Senior Special Obligation (Urbana Community Development Authority), “B”, 4%, 7/01/2040		180,000	167,413
Frederick County, MD, Senior Special Obligation Refunding (Urbana Community Development Authority), “A”, 5%, 7/01/2026		820,000	856,814
Frederick County, MD, Special Tax Limited Obligation Refunding (Jefferson Technology Park Project), “A”, 5%, 7/01/2043 (n)		250,000	248,460
Howard County, MD, Special Obligation (Annapolis Junction Town Center Project), 6.1%, 2/15/2044		230,000	230,055
Howard County, MD, Special Obligation (Downtown Columbia Project), “A”, 4.5%, 2/15/2047 (n)		300,000	278,787
Maryland Economic Development Corp., Special Obligation (Port Covington Project), 4%, 9/01/2050 (n)		500,000	419,006
			$4,154,191
Tobacco – 1.0%
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020A-2, “1”, 4%, 6/01/2048	$	410,000	$378,660
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020B-2, “2”, 5%, 6/01/2055		500,000	469,878
Golden State, CA, Tobacco Securitization Corp., Tobacco Settlement Rev., Taxable, “B-1”, 3.85%, 6/01/2050		360,000	332,995
			$1,181,533

4

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Toll Roads – 1.3%
Metropolitan Washington, D.C., Airport Authority, Dulles Toll Road Rev. (Dulles Metrorail and Capital Improvement Projects), “A”, AGM, 4%, 10/01/2052	$	500,000	$484,135
Virginia Small Business Financing Authority Senior Lien Refunding Rev. (95 Express Lanes LLC Project), 5%, 1/01/2035		915,000	1,000,128
			$1,484,263
Transportation - Special Tax – 4.5%
Maryland Department of Transportation, Consolidated Transportation, 4%, 12/15/2029	$	1,500,000	$1,500,403
Maryland Department of Transportation, Consolidated Transportation, “A”, 3%, 10/01/2033		500,000	492,910
Metropolitan Transportation Authority, NY, Refunding Rev. (Climate Bond Certified), “E”, 4%, 11/15/2045		1,000,000	974,619
New Jersey Transportation Trust Fund Authority, “CC”, 5.5%, 6/15/2050		75,000	83,982
Washington, D.C., Metropolitan Area Transit Authority Gross Rev., 5%, 7/01/2037		440,000	466,657
Washington, D.C., Metropolitan Area Transit Authority Gross Rev., 5%, 7/01/2038		440,000	464,126
Washington, D.C., Metropolitan Area Transit Authority Gross Rev., 5%, 7/01/2043		1,140,000	1,193,221
			$5,175,918
Universities - Colleges – 3.4%
Maryland Health & Higher Educational Facilities Authority Rev. (Goucher College), “A”, 5%, 7/01/2044	$	500,000	$505,394
Maryland Health & Higher Educational Facilities Authority Rev. (Loyola University Maryland), 5%, 10/01/2032		500,000	503,600
Maryland Health & Higher Educational Facilities Authority Rev. (Loyola University Maryland), “A”, 5%, 10/01/2049		1,000,000	1,053,480
Maryland Health & Higher Educational Facilities Authority Rev. (Maryland Institute College of Art Issue), 5%, 6/01/2033		450,000	461,422
Maryland Health & Higher Educational Facilities Authority Rev. (Stevenson University), “A”, 4%, 6/01/2046		750,000	674,543
Maryland Health & Higher Educational Facilities Authority Rev. (Stevenson University), “A”, 4%, 6/01/2051		250,000	217,085
Massachusetts Development Finance Agency Rev. (Suffolk University), 4%, 7/01/2051		420,000	353,147
Puerto Rico Industrial, Tourist, Educational, Medical & Environmental Control Facilities Financing Authority, Higher Education Rev. (International American University of Puerto Rico Project), 5%, 10/01/2031		75,000	75,112
Virginia College Building Authority, Educational Facilities Rev. (Marymount University Project), “B”, 5.25%, 7/01/2035 (n)		110,000	110,438
			$3,954,221
Universities - Dormitories – 2.2%
Maryland Economic Development Corp., Senior Student Housing Rev. (University of Maryland, College Park Projects), AGM, 5%, 6/01/2035	$	750,000	$782,422
Maryland Economic Development Corp., Student Housing Rev. (Morgan State University Project), 5%, 7/01/2050		1,000,000	1,009,582
Maryland Economic Development Corp., Student Housing Rev. (Salisbury University Project), 5%, 6/01/2027		410,000	410,172
Maryland Economic Development Corp., Student Housing Rev. (Salisbury University Project), 5%, 6/01/2030		300,000	300,092
			$2,502,268
Utilities - Electric Power – 0.4%
Texas Municipal Power Agency, Transmission System Rev., AGM, 2%, 9/01/2033	$	555,000	$465,488
Utilities - Municipal Owned – 0.3%
Puerto Rico Electric Power Authority Refunding Rev., “DDD”, 5%, 7/01/2020 (a)(d)	$	10,000	$2,600
Puerto Rico Electric Power Authority Refunding Rev., “DDD”, 5%, 7/01/2021 (a)(d)		100,000	26,000
Puerto Rico Electric Power Authority Refunding Rev., “DDD”, 5%, 7/01/2022 (a)(d)		160,000	41,600
Puerto Rico Electric Power Authority Refunding Rev., “VV”, NPFG, 5.25%, 7/01/2034		10,000	9,857
Puerto Rico Electric Power Authority Rev., “A”, 5%, 7/01/2029 (a)(d)		250,000	65,000
Puerto Rico Electric Power Authority Rev., “A”, 5%, 7/01/2042 (a)(d)		40,000	10,400
Puerto Rico Electric Power Authority Rev., “AAA”, 5.25%, 7/01/2021 (a)(d)		20,000	5,200
Puerto Rico Electric Power Authority Rev., “AAA”, 5.25%, 7/01/2030 (a)(d)		10,000	2,600
Puerto Rico Electric Power Authority Rev., “CCC”, 5.25%, 7/01/2027 (a)(d)		95,000	24,700
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2021 (a)(d)		45,000	11,700
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2023 (a)(d)		40,000	10,400
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2027 (a)(d)		10,000	2,600
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2037 (a)(d)		125,000	32,500
Puerto Rico Electric Power Authority Rev., “WW”, 5.375%, 7/01/2022 (a)(d)		10,000	2,600
Puerto Rico Electric Power Authority Rev., “WW”, 5.25%, 7/01/2025 (a)(d)		20,000	5,200
Puerto Rico Electric Power Authority Rev., “ZZ”, 5%, 7/01/2018 (a)(d)		60,000	15,600
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2023 (a)(d)		65,000	16,900
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2024 (a)(d)		20,000	5,200
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2026 (a)(d)		65,000	16,900

5

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Utilities - Municipal Owned – continued
Puerto Rico Electric Power Authority Rev., Taxable, “EEE”, 6.05%, 7/01/2032 (a)(d)	$	50,000	$12,125
			$319,682
Utilities - Other – 2.0%
California Community Choice Financing Authority, Clean Energy Project Rev., “C”, 5.25%, 1/01/2054 (Put Date 10/01/2031)	$	720,000	$761,631
Patriots Energy Group Financing Agency, SC, Gas Supply Rev., “B-1”, 5.25%, 2/01/2054 (Put Date 3/01/2031)		400,000	435,592
Southeast Alabama Energy Authority Commodity Supply Rev. (Project No. 5), “A”, 5.25%, 1/01/2054 (Put Date 7/01/2029)		665,000	707,690
Tennergy Corp., TN, Gas Supply Rev., “A”, 5.5%, 10/01/2053 (Put Date 12/01/2030)		410,000	437,633
			$2,342,546
Water & Sewer Utility Revenue – 1.2%
Baltimore, MD, Project Rev. (Mayor and City Council of Baltimore Water Projects), “A”, 4%, 7/01/2038	$	550,000	$572,650
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 7/01/2036		20,000	20,627
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 1/01/2046		105,000	106,589
Guam Waterworks Authority Rev. (Water and Wastewater System), “A”, 5%, 7/01/2029		205,000	206,643
Guam Waterworks Authority Rev. (Water and Wastewater System), “A”, 5%, 7/01/2035		205,000	206,483
Guam Waterworks Authority Rev. (Water and Wastewater System), “A”, 5%, 1/01/2050		130,000	133,800
Michigan Finance Authority Local Government Loan Program Rev. (Detroit Water and Sewerage Department Sewage Disposal System Rev. Refunding Second Lien Local Project), “C-7”, NPFG, 5%, 7/01/2032		25,000	25,137
Michigan Finance Authority Local Government Loan Program Rev. (Detroit Water and Sewerage Department Water Supply System Rev. Refunding Second Lien Local Project), “D-6”, NPFG, 5%, 7/01/2036		30,000	30,129
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		35,000	35,135
Mississippi Development Bank Special Obligation (Jackson Water and Sewer System Rev. Bond Project), AGM, 6.875%, 12/01/2040		50,000	50,180
			$1,387,373
Total Municipal Bonds			$110,846,990
Bonds – 0.2%
Consumer Services – 0.2%
Toll Road Investors Partnership II LP, Capital Appreciation, NPFG, 0%, 2/15/2025 (n)	$	165,000	$152,677
Toll Road Investors Partnership II LP, Capital Appreciation, NPFG, 0%, 2/15/2043 (n)		378,198	120,302
Total Bonds			$272,979
Contingent Value Instruments – 0.1%
General Obligations - General Purpose – 0.1%
Commonwealth of Puerto Rico, General Obligation Contingent Value Instrument, 11/01/2043	$	183,846	$100,196
Investment Companies (h) – 3.1%
Money Market Funds – 3.1%
MFS Institutional Money Market Portfolio, 5.42% (v)		3,608,070	$3,608,792
Other Assets, Less Liabilities – 1.0%			1,188,332
Net Assets – 100.0%			$116,017,289

(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 $3,608,792 and $111,220,165, 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 $2,392,753, representing 2.1% 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.

6

Portfolio of Investments (unaudited) – continued

The following abbreviations are used in this report and are defined:
AAC	Ambac Assurance Corp.
AGM	Assured Guaranty Municipal
BAM	Build America Mutual
COP	Certificate of Participation
FHA	Federal Housing Administration
GNMA	Government National Mortgage Assn.
NPFG	National Public Finance Guarantee Corp.

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

7

Supplemental Information

12/31/23 (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

Subject to its oversight, the fund's Board of Trustees has delegated primary responsibility for determining or causing to be determined the value of the fund’s investments to MFS as the fund's adviser, pursuant to the fund’s valuation policy and procedures which have been adopted by the adviser and approved by the Board. In accordance with Rule 2a-5 under the Investment Company Act of 1940, the Board of Trustees designated the adviser as the “valuation designee” of the fund. If the adviser, as valuation designee, determines that reliable market quotations are not readily available for an investment, the investment is valued at fair value as determined in good faith by the adviser in accordance with the adviser’s fair valuation policy and procedures.

Under the fund's valuation policy and procedures, 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. Open-end investment companies are generally valued at net asset value per share.

Under the fund’s valuation policy and procedures, market quotations are not considered to be readily available for debt instruments, floating rate loans, and many types of derivatives. These investments are generally valued at fair value based on information from third-party pricing services or otherwise determined by the adviser in accordance with the adviser’s fair valuation policy and procedures. 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, spreads and other market data. An investment may also be valued at fair value if the adviser determines that the 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 significant unobservable inputs, which may include the adviser's own assumptions in determining the fair value of investments. The following is a summary of the levels used as of December 31, 2023 in valuing the fund's assets and liabilities:

Financial Instruments	Level 1	Level 2	Level 3	Total
Municipal Bonds	$—	$110,947,186	$—	$110,947,186
U.S. Corporate Bonds	—	272,979	—	272,979
Mutual Funds	3,608,792	—	—	3,608,792
Total	$3,608,792	$111,220,165	$—	$114,828,957

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	$2,575,767	$34,590,165	$33,557,917	$890	$(113)	$3,608,792

8

Supplemental Information (unaudited) – continued

Affiliated Issuers	Dividend Income	Capital Gain Distributions
MFS Institutional Money Market Portfolio	$77,199	$—

(3) Jurisdiction Weightings

Jurisdiction weighting percentages based on net assets, as of December 31, 2023, are as follows:

Maryland	72.8%
Washington DC	5.4%
New York	4.3%
Puerto Rico	3.5%
Virginia	1.7%
California	1.3%
Illinois	1.3%
Alabama	1.1%
Texas	1.0%
South Carolina	0.9%
Guam	0.7%
Ohio	0.7%
New Jersey	0.5%
Pennsylvania	0.4%
Tennessee	0.4%
Massachusetts	0.3%
New Hampshire	0.2%
Wisconsin	0.2%
Colorado	0.1%
Indiana	0.1%
Iowa	0.1%
Michigan	0.1%
Mississippi (o)	0.0%
U.S. Virgin Islands (o)	0.0%

(o) Less than 0.1%.

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

9