Quarterly Report

June 30, 2020

MFS^® Mississippi
Municipal Bond Fund

Portfolio of Investments

6/30/20 (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 – 100.2%
Airport Revenue – 1.6%
Dallas and Fort Worth, TX, International Airport Rev., “B”, 5%, 11/01/2044	$	115,000	$123,369
Dallas and Fort Worth, TX, International Airport Rev., “C”, 5%, 11/01/2045		75,000	78,227
Metropolitan Nashville, TN, Airport Authority Rev., “B”, 5%, 7/01/2038		845,000	1,049,287
Wayne County, MI, Airport Authority Rev. (Detroit Metropolitan Wayne County Airport), “B”, 5%, 12/01/2044		45,000	50,137
Wayne County, MI, Airport Authority Rev. (Detroit Metropolitan Wayne County Airport), “B”, BAM, 5%, 12/01/2039		230,000	257,899
Wayne County, MI, Airport Authority Rev. (Detroit Metropolitan Wayne County Airport), “C”, 5%, 12/01/2039		35,000	38,855
Wayne County, MI, Airport Authority Rev. (Detroit Metropolitan Wayne County Airport), “C”, 5%, 12/01/2044		60,000	66,185
			$1,663,959
General Obligations - General Purpose – 19.4%
Biloxi, MS, Development Bank Special Obligation, 4%, 3/01/2037	$	500,000	$584,475
Bridgeview, IL, Stadium and Redevelopment Projects, AAC, 5.14%, 12/01/2036		220,000	210,723
Canton, MS, Mississippi Development Bank Special Obligation, “A”, AGM, 5.75%, 10/01/2031 (Prerefunded 10/01/2021)		625,000	666,475
Chicago, IL, General Obligation (Neighborhood Alive 21 Program), “B”, 5.5%, 1/01/2037		45,000	47,991
Chicago, IL, General Obligation Refunding Project, “A”, 5.25%, 1/01/2030		30,000	31,613
Chicago, IL, General Obligation, “A”, 5.5%, 1/01/2033		65,000	69,831
Chicago, IL, General Obligation, “A”, 5.5%, 1/01/2035		50,000	56,253
Chicago, IL, General Obligation, “D”, 5.5%, 1/01/2040		20,000	21,232
Chicago, IL, General Obligation, “F”, 5.5%, 1/01/2042		135,000	142,907
Commonwealth of Puerto Rico, General Obligation, “A”, 8%, 7/01/2035 (a)(d)		1,025,000	615,000
Commonwealth of Puerto Rico, Public Improvement, AGM, 5.25%, 7/01/2021		400,000	400,000
Hattiesburg, MS, Development Bank Special Obligation, 5.25%, 2/01/2049		750,000	940,095
Mississippi Development Bank Special Obligation (Harrison County Coliseum), “A”, 5.25%, 1/01/2034		1,000,000	1,366,730
Mississippi Development Bank Special Obligation (Hinds County), 5%, 11/01/2032		500,000	622,930
Mississippi Development Bank Special Obligation (Hinds County), 4%, 11/01/2042		500,000	561,675
Mississippi Development Bank Special Obligation (Rankin County), 5%, 3/01/2031		1,000,000	1,238,390
Mississippi Development Bank Special Obligation (Rankin County), 5%, 3/01/2032		1,000,000	1,231,710
Mississippi Development Bank Special Obligation (Vicksburg, Mississippi Sports Complex General Obligation Bond Project), BAM, 5%, 7/01/2048		1,000,000	1,190,770
Mississippi General Obligation, “B”, 3%, 10/01/2035		875,000	955,754
Puerto Rico Public Buildings Authority Rev., “M-2”, AAC, 10%, 7/01/2035		150,000	159,225
State of Illinois, 5.5%, 5/01/2039		150,000	168,781
State of Illinois, “A”, 4%, 12/01/2033		35,000	34,587
State of Mississippi, “A”, 5%, 10/01/2033		1,000,000	1,255,420
State of Mississippi, “A”, 5%, 11/01/2036		1,000,000	1,221,200
State of Mississippi, “B”, 5%, 12/01/2033		1,000,000	1,234,450
State of Mississippi, “B”, 4%, 10/01/2036		1,000,000	1,210,330
State of Mississippi, “B”, 4%, 10/01/2038		1,000,000	1,194,060
State of Mississippi, “D”, 4%, 12/01/2030		1,000,000	1,201,300
State of Mississippi, Capital Improvement Projects, “A”, 5%, 10/01/2030 (Prerefunded 10/01/2021)		1,000,000	1,058,330
			$19,692,237
General Obligations - Schools – 11.9%
Berks County, PA, Reading School District, AGM, 5%, 3/01/2036	$	20,000	$24,057
Lamar County, MS, School District, 5%, 9/01/2031 (Prerefunded 9/01/2023)		1,095,000	1,254,322
Mississippi Development Bank Special Obligation (Canton Public School District), AGM, 5%, 12/01/2031		1,000,000	1,195,860
Mississippi Development Bank Special Obligation (Clinton Public School District), 4%, 4/01/2036		500,000	583,155
Mississippi Development Bank Special Obligation (Clinton Public School District), 4%, 4/01/2037		500,000	581,125
Mississippi Development Bank Special Obligation (Gulfport School District), BAM, 5%, 4/01/2031		500,000	559,915
Mississippi Development Bank Special Obligation (Gulfport School District), BAM, 5%, 4/01/2032		500,000	558,095
Mississippi Development Bank Special Obligation (Hinds County School District), 5%, 3/01/2043		450,000	549,063
Mississippi Development Bank Special Obligation (Jackson Public School District), BAM, 5.25%, 10/01/2037		1,000,000	1,255,270
Mississippi Development Bank Special Obligation (Vicksburg Warren School District General Obligation Project), BAM, 5%, 3/01/2048		1,500,000	1,818,855
Natchez-Adams, MS, School District Trust Certificates, 5%, 2/01/2025		470,000	549,750
Natchez-Adams, MS, School District Trust Certificates, 5%, 2/01/2030		1,245,000	1,595,306

1

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
General Obligations - Schools – continued
Rankin County, MS, Development Bank Special Obligation (School District General Obligation Project), 4%, 6/01/2043	$	750,000	$840,413
San Diego, CA, Unified School District (Election of 2008), Capital Appreciation, “C”, 0%, 7/01/2035		1,020,000	740,989
			$12,106,175
Healthcare Revenue - Hospitals – 12.4%
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (CommonSpirit Health), “A-1”, 4%, 8/01/2044	$	5,000	$5,388
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (CommonSpirit Health), “A-2”, 5%, 8/01/2044		10,000	11,739
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (CommonSpirit Health), “A-2”, 5%, 8/01/2049		5,000	5,830
Colorado Health Facilities Authority Rev. (CommonSpirit Health), “A-2”, 4%, 8/01/2044		50,000	53,880
Gulfport, MS, Hospital Facilities Rev. (Memorial Hospital at Gulfport Project), 5%, 7/01/2027		500,000	565,055
Hamilton County, OH, Hospital Facilities Improvement Refunding Rev. (Trihealth, Inc. Obligated Group Project), “A”, 5%, 8/15/2033		45,000	57,117
Hamilton County, OH, Hospital Facilities Improvement Refunding Rev. (Trihealth, Inc. Obligated Group Project), “A”, 5%, 8/15/2034		75,000	94,961
Hamilton County, OH, Hospital Facilities Improvement Refunding Rev. (Trihealth, Inc. Obligated Group Project), “A”, 5%, 8/15/2035		60,000	75,604
Knox County, IN, Health Educational & Housing Facility Rev. (University Health System, Inc.), “A”, 5%, 9/01/2030		465,000	559,744
Massachusetts Development Finance Agency Rev. (Partners Healthcare System Issue), “S”, 4%, 7/01/2041		535,000	600,340
Massachusetts Development Finance Agency Rev., “J-2”, 5%, 7/01/2048		460,000	535,012
Miami-Dade County, FL, Health Facilities Authority Hospital Rev., 6%, 8/01/2030 (Prerefunded 8/01/2020)		60,000	60,269
Miami-Dade County, FL, Health Facilities Authority Hospital Rev., Unrefunded Balance, 6%, 8/01/2030		20,000	20,075
Mississippi Development Bank Special Obligation (Magnolia Regional Health Center Project), “A”, 6.75%, 10/01/2036		500,000	500,675
Mississippi Hospital Equipment & Facilities Authority Rev. (Baptist Memorial Healthcare), “A”, 5%, 9/01/2022		1,000,000	1,068,700
Mississippi Hospital Equipment & Facilities Authority Rev. (Baptist Memorial Healthcare), “A”, 5%, 9/01/2044 (Put Date 9/01/2025)		500,000	563,175
Mississippi Hospital Equipment & Facilities Authority Rev. (Clay County Medical Corp.), 5%, 10/01/2039		2,100,000	2,124,360
Mississippi Hospital Equipment & Facilities Authority Rev. (Forrest County General Hospital Refunding Project), “A”, 4%, 1/01/2040		1,000,000	1,123,880
Mississippi Hospital, Equipment & Facilities Authority Refunding Rev. (Forrest County General Hospital Refunding Project), “A”, 5%, 1/01/2028		575,000	707,411
Mississippi Hospital, Equipment & Facilities Authority Rev. (North Mississippi Health Services), “I”, 5%, 10/01/2020		1,300,000	1,311,076
Mississippi Hospital, Equipment & Facilities Authority Rev. (North Mississippi Health Services), “IV”, 5%, 10/01/2037 (w)		1,500,000	1,815,240
Spartanburg County, SC, Regional Health Services District Hospital Rev., “A”, 4%, 4/15/2043		655,000	708,055
			$12,567,586
Industrial Revenue - Other – 0.5%
Port Beaumont, TX, Navigation District Facility Rev. (Jefferson Gulf Coast Energy Project), “A”, 4%, 1/01/2050 (n)	$	200,000	$190,668
Tuscaloosa County, AL, Industrial Development Authority, Gulf Opportunity Zone (Hunt Refining Project), “A”, 5.25%, 5/01/2044		290,000	316,503
			$507,171
Industrial Revenue - Paper – 1.8%
Lowndes County, MS, Solid Waste Disposal & Pollution Control Rev. (Weyerhaeuser Co.), 6.8%, 4/01/2022	$	750,000	$824,175
Warren County, MS, Environmental Improvement Rev. (International Paper Co. Project), “B”, 1.6%, 8/01/2027 (Put Date 6/16/2025) (w)		1,000,000	1,005,690
			$1,829,865
Multi-Family Housing Revenue – 1.0%
Mississippi Home Corp., Multi-Family Rev. (Providence Place of Senatobia LLC), GNMA, 5.35%, 8/20/2048	$	1,000,000	$1,040,770
Sales & Excise Tax Revenue – 4.8%
Colorado Regional Transportation District, Private Activity Rev. (Denver Transportation Partners), 6%, 1/15/2041	$	450,000	$450,756
Guam Government Business Privilege Tax Rev., “A”, 5.25%, 1/01/2036		295,000	303,245
Guam Government Business Privilege Tax Rev., “D”, 5%, 11/15/2031		270,000	295,002
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2026		40,000	46,317
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2027		80,000	94,238
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2028		80,000	95,993
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2029		15,000	18,290
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2030		35,000	43,142
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2036		25,000	29,741

2

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Sales & Excise Tax Revenue – continued
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 5%, 1/01/2037	$	45,000	$54,077
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 4%, 1/01/2038		35,000	37,420
Illinois Sales Tax Securitization Corp., Second Lien, “A”, 4%, 1/01/2039		30,000	31,978
Massachusetts Bay Transportation Authority, Sales Tax Rev., “A-1”, 5.25%, 7/01/2029		750,000	1,023,345
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-1”, 4.55%, 7/01/2040		20,000	20,390
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-1”, 5%, 7/01/2058		929,000	971,316
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.329%, 7/01/2040		203,000	203,940
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.329%, 7/01/2040		71,000	71,329
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.536%, 7/01/2053		1,000	1,013
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.784%, 7/01/2058		33,000	34,025
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2024		2,000	1,802
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2027		38,000	31,276
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2029		7,000	5,343
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2031		346,000	243,601
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2033		330,000	213,322
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2046		1,891,000	533,356
			$4,854,257
Single Family Housing - State – 5.9%
Connecticut Housing Finance Authority Rev. (Housing Mortgage Finance Program), “D-1”, GNMA, 4%, 11/15/2047	$	445,000	$479,483
Iowa Finance Authority, Single Family Mortgage Rev., “A”, GNMA, 4%, 7/01/2047		445,000	479,140
Maryland Community Development Administration, Department of Housing & Community Development Housing Rev., “A”, 4.25%, 9/01/2049		475,000	526,818
Mississippi Home Corp., Single Family Mortgage Rev., “A”, 3.75%, 12/01/2035		750,000	842,437
Mississippi Home Corp., Single Family Mortgage Rev., “A”, FNMA, 3.875%, 12/01/2043		750,000	821,168
Mississippi Home Corp., Single Family Mortgage Rev., “A”, GNMA, 2.45%, 12/01/2039		700,000	715,687
Mississippi Home Corp., Single Family Mortgage Rev., “B”, GNMA, 2.875%, 12/01/2043		1,000,000	1,055,250
Pennsylvania Housing Finance Agency, Single Family Mortgage Rev., “125A”, 3.7%, 10/01/2037		485,000	533,825
Tennessee Housing Development Agency Residential Finance Program, “1”, 4.25%, 1/01/2050		470,000	520,835
			$5,974,643
State & Local Agencies – 9.5%
Commonwealth of Pennsylvania, Tobacco Master Settlement Financing Authority Rev., 5%, 6/01/2032	$	25,000	$30,780
Commonwealth of Pennsylvania, Tobacco Master Settlement Financing Authority Rev., 5%, 6/01/2033		25,000	30,587
Commonwealth of Pennsylvania, Tobacco Master Settlement Financing Authority Rev., 5%, 6/01/2034		10,000	12,193
Maryland Stadium Authority Rev., Baltimore City Public Schools Construction and Revitalization Program, “A”, 5%, 5/01/2047		340,000	402,257
Mississippi Development Bank Special Obligation (Capital Projects), AGM, 5%, 7/01/2027		640,000	642,035
Mississippi Development Bank Special Obligation (Department of Corrections), “C”, 5.25%, 8/01/2027 (Prerefunded 8/01/2020)		1,000,000	1,004,020
Mississippi Development Bank Special Obligation (Department of Rehabilitation Services Capital Improvement Project), AGM, 5%, 7/01/2023		345,000	359,914
Mississippi Development Bank Special Obligation (Department of Rehabilitation Services Capital Improvement Project), AGM, 5%, 7/01/2024		360,000	375,257
Mississippi Development Bank Special Obligation (Department of Rehabilitation Services Capital Improvement Project), AGM, 5%, 7/01/2025		380,000	395,538
Mississippi Development Bank Special Obligation (Desoto County Mississippi Highway Construction Project), 5%, 1/01/2029		500,000	553,000
Mississippi Development Bank Special Obligation (Desoto County Mississippi Highway Construction Project), 5%, 1/01/2030		500,000	553,000
Mississippi Development Bank Special Obligation (Jackson County), ASSD GTY, 5%, 7/01/2022 (Prerefunded 7/01/2021)		500,000	523,330
Mississippi Development Bank Special Obligation (Laurel Highway Refunding Project), “B”, 4%, 1/01/2022		735,000	774,462
Mississippi Development Bank Special Obligation (Montfort Jones Memorial Hospital Project), 5.75%, 5/01/2036		500,000	515,650
Mississippi Development Bank Special Obligation (Singing River Health System), ASSD GTY, 5.375%, 7/01/2036 (Prerefunded 7/01/2021)		500,000	525,195
Mississippi Development Bank Special Obligation (Tupelo Public Improvement Rev. Project), 5%, 7/01/2049		1,500,000	1,865,325
New Jersey Economic Development Authority Rev., School Facilities Construction Rev., “LLL”, 5%, 6/15/2039		210,000	234,018
New Jersey Economic Development Authority Rev., School Facilities Construction Rev., “LLL”, 5%, 6/15/2044		355,000	390,678
New Jersey Economic Development Authority Rev., School Facilities Construction, “AAA”, 5%, 6/15/2026		100,000	112,921
Orangeburg County, SC, Facilities Corp. Installment Purchase Rev. (Detention Center Project), 4%, 12/01/2042		280,000	310,201
			$9,610,361

3

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Student Loan Revenue – 0.1%
Iowa Student Loan Liquidity Corp. Rev., “B”, 3%, 12/01/2039	$	45,000	$43,883
Iowa Student Loan Liquidity Corp. Rev., “B”, 3.5%, 12/01/2044		110,000	104,199
			$148,082
Tax - Other – 4.4%
Birmingham-Jefferson, AL, Civic Center Authority, “B”, 5%, 7/01/2043	$	455,000	$447,151
Mississippi Development Bank Special Obligation (Jackson Public School District Limited Tax Refunding Note Project), “B”, 5%, 10/01/2023		830,000	904,542
Puerto Rico Convention Center District Authority, Hotel Occupancy Tax Rev., “A”, AAC, 5%, 7/01/2031		510,000	510,143
Puerto Rico Infrastructure Financing Authority Special Tax Rev., “C”, AAC, 5.5%, 7/01/2027		315,000	343,914
State of Mississippi, Gaming Tax Rev., “A”, 4%, 10/15/2038		1,000,000	1,079,530
State of Mississippi, Gaming Tax Rev., “E”, 5%, 10/15/2030		1,040,000	1,187,420
			$4,472,700
Tobacco – 1.4%
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020A-2, “1”, 5%, 6/01/2036	$	70,000	$89,107
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020A-2, “1”, 4%, 6/01/2048		115,000	124,284
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020B-2, “2”, 5%, 6/01/2055		560,000	589,674
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020B-3, Capital Appreciation, “2”, 0%, 6/01/2057		1,285,000	178,384
Illinois Railsplitter Tobacco Settlement Authority Rev., 6%, 6/01/2028 (Prerefunded 6/01/2021)		420,000	441,752
			$1,423,201
Toll Roads – 0.8%
Texas Private Activity Surface Transportation Corp., Senior Lien Rev. (LBJ Infrastructure Group IH-635 Managed Lanes Project), 7%, 6/30/2040	$	130,000	$130,715
Texas Private Activity Surface Transportation Corp., Senior Lien Rev. (NTE Mobility Partners Segments 3 LLC Segments 3A & 3B Facility), 7%, 12/31/2038		110,000	126,048
Texas Private Activity Surface Transportation Corp., Senior Lien Rev. (NTE Mobility Partners Segments 3 LLC Segments 3A & 3B Facility), 6.75%, 6/30/2043		85,000	96,614
Virginia Small Business Financing Authority Rev. (Elizabeth River Crossings Opco LLC Project), 6%, 1/01/2037		160,000	169,792
Virginia Small Business Financing Authority Rev. (Elizabeth River Crossings Opco LLC Project), 5.5%, 1/01/2042		310,000	324,533
			$847,702
Transportation - Special Tax – 3.0%
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “J”, NATL, 5%, 7/01/2029	$	10,000	$10,040
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “L”, AAC, 5.25%, 7/01/2038		910,000	944,061
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “L”, ASSD GTY, 5.25%, 7/01/2041		135,000	146,266
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “L”, NATL, 5.25%, 7/01/2035		255,000	260,013
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “N”, AAC, 5.5%, 7/01/2029		555,000	605,106
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., Capital Appreciation, “N”, AAC, 0%, 7/01/2021		35,000	35,000
Metropolitan Transportation Authority Rev., NY, “E”, 4%, 9/01/2020		150,000	150,264
Metropolitan Transportation Authority Rev., NY, Anticipation Note, “B-2”, 5%, 5/15/2021		350,000	357,315
Metropolitan Transportation Authority Rev., NY, Anticipation Note, “D-1”, 5%, 9/01/2022		255,000	267,954
New Jersey Transportation Trust Fund Authority, Federal Highway Reimbursement Rev., “A-1”, 5%, 6/15/2027		165,000	186,448
New Jersey Transportation Trust Fund Authority, Transportation System, “A”, 5.25%, 12/15/2021		55,000	57,337
			$3,019,804
Universities - Colleges – 12.3%
Massachusetts Health & Educational Facilities Authority Rev. (Massachusetts Institute of Technology), “I-1”, 5.2%, 1/01/2028	$	920,000	$1,220,776
Medical Center, Educational Building Corp. Rev. (University of Mississippi Medical Center), “B”, AAC, 5.5%, 12/01/2023		615,000	672,675
Mississippi State University, Educational Building Corp. Refunding Rev. (Mississippi State University Facilities Refinancing), “A”, 4%, 8/01/2043		600,000	676,248
Mississippi State University, Educational Building Corp. Rev. (Mississippi State University Refunding and Improvements Project), 5.25%, 8/01/2038 (Prerefunded 8/01/2023)		1,000,000	1,151,000
Mississippi State University, Educational Building Corp. Rev. (Residence Hall Construction and Refunding Project), 5%, 8/01/2036 (Prerefunded 8/01/2021)		1,585,000	1,666,009
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

4

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Universities - Colleges – continued
University of Mississippi Medical Center, Educational Building Corp. Rev. (New Facilities & Refinancing Project), “A”, 4%, 6/01/2047	$	1,000,000	$1,108,130
University of Mississippi Medical Center, Educational Building Corp. Rev. (New Facilities & Refinancing Project), “A”, 5%, 6/01/2047		1,250,000	1,477,775
University of Southern Mississippi, Educational Building Corp. Rev. (Facilities Refinancing Project), 5%, 9/01/2034		1,480,000	1,771,959
University of Southern Mississippi, Educational Building Corp. Rev. (Facilities Refinancing Project), “A”, 5%, 3/01/2028		745,000	874,809
University of Southern Mississippi, Educational Building Corp. Rev. (Facilities Refinancing Project), “A”, 5%, 9/01/2035		1,515,000	1,808,152
			$12,432,524
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	$	220,000	$225,500
Utilities - Municipal Owned – 2.8%
Guam Power Authority Rev., “A”, AGM, 5%, 10/01/2033	$	315,000	$345,656
Guam Power Authority Rev., “A”, AGM, 5%, 10/01/2039		75,000	81,446
Guam Power Authority Rev., “A”, AGM, 5%, 10/01/2044		85,000	91,727
Mississippi Development Bank Special Obligation (Municipal Energy Agency Power Supply Project), AGM, 5%, 3/01/2035		500,000	568,085
Puerto Rico Electric Power Authority Rev., “A”, 5%, 7/01/2029 (a)(d)		240,000	166,800
Puerto Rico Electric Power Authority Rev., “A”, 5%, 7/01/2042 (a)(d)		35,000	24,325
Puerto Rico Electric Power Authority Rev., “AAA”, 5.25%, 7/01/2021 (a)(d)		20,000	13,950
Puerto Rico Electric Power Authority Rev., “AAA”, 5.25%, 7/01/2030 (a)(d)		10,000	6,975
Puerto Rico Electric Power Authority Rev., “CCC”, 5.25%, 7/01/2027 (a)(d)		90,000	62,775
Puerto Rico Electric Power Authority Rev., “DDD”, 5%, 7/01/2021 (a)(d)		90,000	62,550
Puerto Rico Electric Power Authority Rev., “DDD”, 5%, 7/01/2021 (a)(d)		10,000	6,950
Puerto Rico Electric Power Authority Rev., “DDD”, 5%, 7/01/2022 (a)(d)		150,000	104,250
Puerto Rico Electric Power Authority Rev., “DDD”, AGM, 3.625%, 7/01/2023		15,000	15,007
Puerto Rico Electric Power Authority Rev., “DDD”, AGM, 3.65%, 7/01/2024		80,000	80,020
Puerto Rico Electric Power Authority Rev., “EEE”, 6.05%, 7/01/2032 (a)(d)		50,000	34,688
Puerto Rico Electric Power Authority Rev., “SS”, ASSD GTY, 4.375%, 7/01/2030		10,000	10,002
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2021 (a)(d)		40,000	27,800
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2023 (a)(d)		40,000	27,800
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2027 (a)(d)		5,000	3,475
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2037 (a)(d)		120,000	83,400
Puerto Rico Electric Power Authority Rev., “UU”, AGM, 5%, 7/01/2024		500,000	531,635
Puerto Rico Electric Power Authority Rev., “UU”, ASSD GTY, 4.25%, 7/01/2027		60,000	60,020
Puerto Rico Electric Power Authority Rev., “V”, NATL, 5.25%, 7/01/2033		55,000	56,131
Puerto Rico Electric Power Authority Rev., “VV”, NATL, 5.25%, 7/01/2030		105,000	107,295
Puerto Rico Electric Power Authority Rev., “VV”, NATL, 5.25%, 7/01/2032		120,000	122,425
Puerto Rico Electric Power Authority Rev., “VV”, NATL, 5.25%, 7/01/2034		10,000	10,208
Puerto Rico Electric Power Authority Rev., “WW”, 5.375%, 7/01/2022 (a)(d)		10,000	6,988
Puerto Rico Electric Power Authority Rev., “WW”, 5.25%, 7/01/2025 (a)(d)		15,000	10,463
Puerto Rico Electric Power Authority Rev., “ZZ”, 5%, 7/01/2022 (a)(d)		60,000	41,550
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2023 (a)(d)		65,000	45,256
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2024 (a)(d)		20,000	13,950
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2026 (a)(d)		60,000	41,850
			$2,865,452
Utilities - Other – 0.3%
Tennessee Energy Acquisition Corp., Gas Rev., “A”, 5.25%, 9/01/2021	$	185,000	$192,681
Tennessee Energy Acquisition Corp., Gas Rev., “A”, 5.25%, 9/01/2022		95,000	102,239
			$294,920
Water & Sewer Utility Revenue – 6.1%
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 7/01/2036	$	30,000	$34,173
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 1/01/2046		145,000	162,452
Guam Waterworks Authority Rev. (Water and Wastewater System), “A”, 5%, 7/01/2029		30,000	33,572
Guam Waterworks Authority Rev. (Water and Wastewater System), “A”, 5%, 7/01/2035		30,000	33,038
Guam Waterworks Authority Rev. (Water and Wastewater System), “A”, 5%, 1/01/2050		120,000	143,185

5

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Water & Sewer Utility Revenue – continued
Jackson County, MS, Utility Authority Rev. (Water and Wastewater Treatment System), AGM, 5%, 9/01/2040	$	2,000,000	$2,282,540
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		25,000	28,742
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		30,000	34,062
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		15,000	16,882
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	39,233
Mississippi Development Bank Special Obligation (Jackson Water and Sewer System Rev. Bond Project), AGM, 6.875%, 12/01/2040		750,000	880,680
Mississippi Development Bank Special Obligation (Jackson Water and Sewer System Rev. Bond Project), “A”, AGM, 5%, 9/01/2023		1,220,000	1,279,121
West Rankin, MS, Utility Authority Rev., AGM, 5%, 1/01/2048		1,000,000	1,194,170
			$6,161,850
Total Municipal Bonds			$101,738,759
Bonds – 0.1%
Consumer Services – 0.1%
Toll Road Investors Partnership II LP, Capital Appreciation, NATL, 0%, 2/15/2043 (n)	$	300,000	$89,435
Investment Companies (h) – 1.3%
Money Market Funds – 1.3%
MFS Institutional Money Market Portfolio, 0.17% (v)		1,295,389	$1,295,519
Other Assets, Less Liabilities – (1.6)%			(1,648,153)
Net Assets – 100.0%			$101,475,560

(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 $1,295,519 and $101,828,194, 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 $280,103, representing 0.3% 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.
(w)	When-issued security.

The following abbreviations are used in this report and are defined:
AAC	Ambac Assurance Corp.
AGM	Assured Guaranty Municipal
ASSD GTY	Assured Guaranty Insurance Co.
BAM	Build America Mutual
FNMA	Federal National Mortgage Assn.
GNMA	Government National Mortgage Assn.
NATL	National Public Finance Guarantee Corp.

6

Portfolio of Investments (unaudited) – continued

Derivative Contracts at 6/30/20
Futures Contracts
Description	Long/ Short	Currency	Contracts	Notional Amount	Expiration Date	Value/Unrealized Appreciation (Depreciation)
Liability Derivatives
Interest Rate Futures
U.S. Treasury Bond	Short	USD	5	$892,813	September – 2020	$(4,862)

At June 30, 2020, the fund had cash collateral of $25,000 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.

7

Supplemental Information

6/30/20 (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 June 30, 2020 in valuing the fund's assets or liabilities:

Financial Instruments	Level 1	Level 2	Level 3	Total
Municipal Bonds	$—	$101,738,759	$—	$101,738,759
U.S. Corporate Bonds	—	89,435	—	89,435
Mutual Funds	1,295,519	—	—	1,295,519
Total	$1,295,519	$101,828,194	$—	$103,123,713
Other Financial Instruments
Futures Contracts – Liabilities	$(4,862)	$—	$—	$(4,862)

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	$3,902,197	$5,639,527	$8,245,990	$175	$(390)	$1,295,519

8

Supplemental Information (unaudited) – continued

Affiliated Issuers	Dividend Income	Capital Gain Distributions
MFS Institutional Money Market Portfolio	$2,002	$—

(3) Jurisdiction Weightings

Jurisdiction weighting percentages based on net assets, as of June 30, 2020, are as follows:

Mississippi	73.7%
Puerto Rico	8.4%
Massachusetts	3.4%
Tennessee	2.5%
Illinois	1.7%
Guam	1.5%
Ohio	1.2%
New Jersey	1.0%
South Carolina	1.0%
Maryland	0.9%
Alabama	0.8%
New York	0.8%
California	0.7%
Texas	0.7%
Iowa	0.6%
Pennsylvania	0.6%
Virginia	0.6%
Colorado	0.5%
Connecticut	0.5%
Michigan	0.5%
Florida	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.

9