Quarterly Report

December 31, 2019

MFS^® Alabama
Municipal Bond Fund

Portfolio of Investments

12/31/19 (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 – 96.4%
Airport Revenue – 1.9%
Birmingham, AL, Airport Authority Rev., AGM, 5.25%, 7/01/2030	$	1,000,000	$1,017,500
Dallas and Fort Worth, TX, International Airport Rev., “B”, 5%, 11/01/2044		70,000	76,611
Dallas and Fort Worth, TX, International Airport Rev., “C”, 5%, 11/01/2045		45,000	47,844
New York Transportation Development Corp., Special Facilities Rev. (LaGuardia Airport Terminal B Redevelopment Project), “A”, AGM, 4%, 7/01/2037		345,000	367,442
			$1,509,397
General Obligations - General Purpose – 13.5%
Birmingham, AL, General Obligation Warrants, “B”, 5%, 12/01/2043	$	245,000	$293,407
Bridgeview, IL, Stadium and Redevelopment Projects, AAC, 5.14%, 12/01/2036		160,000	161,851
Chicago, IL, “A”, 5.5%, 1/01/2033		205,000	232,456
Chicago, IL, “B”, 7.375%, 1/01/2033		201,000	240,774
Chicago, IL, “D”, 5.5%, 1/01/2040		15,000	16,821
Commonwealth of Puerto Rico, Public Improvement, “A”, AGM, 5%, 7/01/2035		150,000	159,426
Commonwealth of Puerto Rico, Public Improvement, “A”, NATL, 5.5%, 7/01/2020		145,000	147,355
Commonwealth of Puerto Rico, Public Improvement, “A-4”, AGM, 5.25%, 7/01/2030		20,000	20,234
Commonwealth of Puerto Rico, Public Improvement, “A-4”, AGM, 5%, 7/01/2031		40,000	40,452
Fort Payne, AL, General Obligation Warrants, “A”, AGM, 5%, 5/01/2047		750,000	894,345
Jasper, AL, General Obligation Warrants, 5%, 3/01/2032		500,000	563,135
Madison County, AL, General Obligation Warrants, “B”, 4%, 9/01/2038		1,000,000	1,144,330
Mobile County, AL, General Obligation Improvement Warrants, 5%, 2/01/2038		250,000	309,797
Mobile County, AL, General Obligation Improvement Warrants, 5%, 2/01/2039		250,000	308,987
Mobile County, AL, General Obligation Warrants, 5%, 8/01/2036		500,000	605,430
Montevallo, AL, American Village Public Educational Building Authority Refunding Rev. (Alabama Veterans Living Legacy Project), 4%, 12/01/2033		420,000	475,041
Montevallo, AL, American Village Public Educational Building Authority Refunding Rev. (Alabama Veterans Living Legacy Project), 4%, 12/01/2034		655,000	739,344
Montevallo, AL, American Village Public Educational Building Authority Refunding Rev. (Alabama Veterans Living Legacy Project), 4%, 12/01/2035		250,000	278,708
Puerto Rico Public Buildings Authority Rev., “M-2”, AAC, 10%, 7/01/2035		115,000	121,462
State of Alabama, “A”, 5%, 8/01/2028		1,000,000	1,226,790
State of Illinois, 5%, 11/01/2027		385,000	445,645
Trussville, AL, General Obligation Warrants, “A”, 4%, 8/01/2041		750,000	828,735
Vestavia Hills, AL, 4%, 8/01/2048		500,000	550,115
Vestavia Hills, AL, General Obligation Warrants, 4%, 8/01/2038		1,000,000	1,126,640
			$10,931,280
General Obligations - Schools – 4.7%
Downey, CA, Unified School District (Election of 2014), “B”, 4%, 8/01/2040	$	445,000	$501,742
Huntsville, AL, “A”, 5%, 5/01/2039		1,000,000	1,252,520
Huntsville, AL, School Warrants, “C”, 5%, 11/01/2029 (Prerefunded 11/01/2023)		200,000	229,480
Huntsville, AL, School Warrants, “C”, 5%, 11/01/2030 (Prerefunded 11/01/2023)		1,000,000	1,147,400
Montebello, CA, Unified School District (Election of 2016), “A”, 4%, 8/01/2046		270,000	289,324
Moorpark, CA, Unified School District (Election of 2008), Capital Appreciation, “B”, AGM, 0%, 8/01/2036		570,000	350,977
			$3,771,443
Healthcare Revenue - Hospitals – 10.4%
Alabama Special Care Facilities Financing Authority Rev. (Ascension Health), “C”, 5%, 11/15/2046	$	500,000	$576,060
Alabama Special Care Facilities Financing Authority Rev. (Daughters of Charity), ETM, AAC, 5%, 11/01/2025		865,000	925,905
Birmingham, AL, Special Care Facilities Financing Authority Health Care Rev. (Children's Hospital), 5%, 6/01/2031		750,000	866,805
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (CommonSpirit Health), “A-1”, 4%, 8/01/2044		10,000	10,718
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (CommonSpirit Health), “A-2”, 5%, 8/01/2044		5,000	5,892
Chattanooga, TN, Health, Educational & Housing Facility Board Rev. (CommonSpirit Health), “A-2”, 5%, 8/01/2049		5,000	5,838
Colorado Health Facilities Authority Rev. (CommonSpirit Health), “A-2”, 4%, 8/01/2044		40,000	42,872
Colorado Health Facilities Authority Rev. (CommonSpirit Health), “A-2”, 4%, 8/01/2049		30,000	31,897
DCH Health Care Authority, AL, Health Care Facilities Rev., 5%, 6/01/2033		500,000	570,665

1

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Healthcare Revenue - Hospitals – continued
East Alabama Health Care Authority, Health Care Facilities Rev., “A”, 4%, 9/01/2048	$	500,000	$540,265
Escambia County, FL, Health Facilities Authority (Baptist Hospital, Inc.), “A”, 6%, 8/15/2036		435,000	446,280
Huntsville, AL, Health Care Authority Rev., “A”, 5%, 6/01/2030 (Prerefunded 6/01/2020)		1,000,000	1,015,650
Mobile, AL, Special Care Facilities Financing Authority Rev. (Infirmary Health System, Inc.), “A”, 5.25%, 2/01/2030 (Prerefunded 2/03/2020)		500,000	501,645
New Jersey Health Care Facilities, Financing Authority Rev. (University Hospital), “A”, AGM, 5%, 7/01/2046		50,000	56,192
Spartanburg County, SC, Regional Health Services District Hospital Rev., “A”, 4%, 4/15/2043		425,000	453,547
UAB Medicine Finance Authority Rev., “B”, 5%, 9/01/2035		1,000,000	1,185,990
UAB Medicine Finance Authority, Rev., “B2”, 5%, 9/01/2041		1,000,000	1,176,720
			$8,412,941
Healthcare Revenue - Long Term Care – 1.7%
Birmingham, AL, Special Care Facilities Financing Authority Rev. (Methodist Home for the Aging), 5.75%, 6/01/2045	$	250,000	$279,005
Pell City, AL, Special Care Facilities, Financing Authority Rev. (Noland Health Services, Inc.), 5%, 12/01/2039		1,050,000	1,115,761
			$1,394,766
Industrial Revenue - Other – 0.4%
Tuscaloosa County, AL, Industrial Development Authority, Gulf Opportunity Zone (Hunt Refining Project), “A”, 5.25%, 5/01/2044	$	305,000	$350,555
Industrial Revenue - Paper – 0.4%
Selma, AL, Industrial Development Board Rev., Gulf Opportunity Zone (International Paper Co.), “A”, 5.375%, 12/01/2035	$	300,000	$321,561
Miscellaneous Revenue - Other – 1.2%
Indiana Finance Authority Rev. (Ohio River Bridges East End Crossing Project), “A”, 5%, 7/01/2040	$	65,000	$71,189
Indiana Finance Authority Rev. (Ohio River Bridges East End Crossing Project), “A”, 5%, 7/01/2044		95,000	103,884
New York Liberty Development Corp., Liberty Rev. (3 World Trade Center Project), “1”, 5%, 11/15/2044		260,000	287,342
New York Liberty Development Corp., Liberty Rev. (7 World Trade Center Project), 5%, 9/15/2040		495,000	532,521
			$994,936
Port Revenue – 2.1%
Alabama Port Authority Docks Facilities Refunding Rev., “A”, AGM, 5%, 10/01/2035	$	1,000,000	$1,182,990
Alabama Port Authority Docks Facilities Rev., 6%, 10/01/2040 (Prerefunded 10/01/2020)		500,000	518,105
			$1,701,095
Sales & Excise Tax Revenue – 9.7%
Cherokee County, AL, Board of Education Special Tax School Warrants (Sales Tax), 5%, 12/01/2048	$	1,000,000	$1,190,790
Chicago, IL, Transit Authority Sales Tax Receipts Rev., AGM, 5%, 12/01/2046		425,000	488,580
Colorado Regional Transportation District, Private Activity Rev. (Denver Transportation Partners), 6%, 1/15/2041		325,000	331,458
Elmore County, AL, Board of Education School Tax Warrants, 5%, 8/01/2032		515,000	643,848
Elmore County, AL, Board of Education School Tax Warrants, 4%, 8/01/2038		745,000	830,220
Jefferson County, AL, Board of Education, 4%, 2/01/2042		805,000	873,055
Jefferson County, AL, Limited Obligation Warrants, 5%, 9/15/2033		500,000	598,525
Massachusetts Bay Transportation Authority, Sales Tax Rev., “A”, 5%, 7/01/2031		515,000	686,943
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-1”, 4.55%, 7/01/2040		16,000	16,565
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-1”, 4.75%, 7/01/2053		258,000	269,357
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-1”, 5%, 7/01/2058		395,000	419,107
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.329%, 7/01/2040		164,000	166,250
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.329%, 7/01/2040		58,000	58,796
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.784%, 7/01/2058		25,000	25,966
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2024		1,000	878
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2027		26,000	20,761
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2029		4,000	2,968
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2031		247,000	169,583
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2033		237,000	150,775
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2046		112,000	30,006
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “2019A-1”, 0%, 7/01/2051		144,000	28,104
Tuscaloosa County, AL, Board of Education, School Tax Warrants, 5%, 2/01/2037		750,000	888,607
			$7,891,142

2

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
State & Local Agencies – 5.3%
Alabama Public Health Care Authority Lease Rev. (Department of Public Health Facilities), 5%, 9/01/2030	$	280,000	$324,355
Alabama Public School & College Authority Rev., “B”, 5%, 6/01/2025		800,000	901,200
Anniston, AL, Public Building Authority Rev. (Judicial Center Project), AGM, 5%, 3/01/2032		500,000	518,935
Bessemer, AL, Public Educational Building Authority Rev. (DHR Building Project), “A”, ASSD GTY, 5%, 7/01/2030		385,000	391,768
Colorado State University Board of Governors, System Enterprise Refunding Rev., “E”, 4%, 3/01/2043		315,000	349,155
Golden State, CA, Tobacco Securitization Corp., Tobacco Settlement Rev., “A”, 5%, 6/01/2030		35,000	39,191
Huntsville, AL, Public Building Authority Lease Refunding Rev., 5%, 10/01/2033		500,000	612,175
Maryland Stadium Authority Rev., Baltimore City Public Schools Construction and Revitalization Program, “A”, 5%, 5/01/2047		230,000	275,414
New Jersey Building Authority Rev., Unrefunded Balance, “A”, BAM, 5%, 6/15/2029		10,000	11,778
New York Dormitory Authority Rev., State Personal Income Tax, “A” (Group C), 5%, 2/15/2041		255,000	301,165
Orangeburg County, SC, Facilities Corp. Installment Purchase Rev. (Detention Center Project), 4%, 12/01/2042		185,000	200,594
State Public School Building Authority, PA, School Lease Rev. (School District of Philadelphia Project), “A”, AGM, 5%, 6/01/2033		350,000	410,452
			$4,336,182
Student Loan Revenue – 0.1%
Iowa Student Loan Liquidity Corp. Rev., “B”, 3%, 12/01/2039	$	35,000	$34,654
Iowa Student Loan Liquidity Corp. Rev., “B”, 3.5%, 12/01/2044		90,000	88,337
			$122,991
Tax - Other – 6.3%
Birmingham-Jefferson, AL, Civic Center Authority, “A”, 4%, 7/01/2043	$	750,000	$821,738
Birmingham-Jefferson, AL, Civic Center Authority, “B”, 5%, 7/01/2043		500,000	593,420
Guam Government Ltd. Obligation Rev., “A”, 5%, 12/01/2035		55,000	62,468
Guam Government Ltd. Obligation Rev., “A”, 5%, 12/01/2036		30,000	33,997
Guam Government Ltd. Obligation Rev., “A”, 5%, 12/01/2046		85,000	94,534
Lauderdale County, AL, Agriculture Center Authority Special Tax Rev., 5%, 7/01/2049		1,000,000	1,123,490
Puerto Rico Convention Center District Authority, Hotel Occupancy Tax Rev., “A”, AAC, 5%, 7/01/2031		70,000	71,541
Puerto Rico Infrastructure Financing Authority Special Tax Rev., “C”, AAC, 5.5%, 7/01/2024		105,000	114,437
Puerto Rico Infrastructure Financing Authority Special Tax Rev., “C”, AAC, 5.5%, 7/01/2026		265,000	293,440
Puerto Rico Infrastructure Financing Authority Special Tax Rev., “C”, AAC, 5.5%, 7/01/2027		190,000	211,149
Shelby County, AL, Board of Education Capital Outlay School Warrants (Ten Mill County Tax), 5%, 2/01/2031		500,000	519,565
Tuscaloosa, AL, Board of Education, School Tax Warrants, 5%, 8/01/2036		1,000,000	1,184,130
			$5,123,909
Toll Roads – 0.4%
Virginia Small Business Financing Authority Rev. (Elizabeth River Crossings Opco LLC Project), 6%, 1/01/2037	$	90,000	$99,157
Virginia Small Business Financing Authority Rev. (Elizabeth River Crossings Opco LLC Project), 5.5%, 1/01/2042		180,000	195,071
			$294,228
Transportation - Special Tax – 4.2%
Alabama Federal Aid Highway Finance Authority Special Obligation, “A”, 5%, 9/01/2035	$	500,000	$598,855
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “CC”, AGM, 5.25%, 7/01/2036		145,000	163,936
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “D”, AGM, 5%, 7/01/2032		125,000	127,934
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “L”, AAC, 5.25%, 7/01/2038		325,000	353,918
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “L”, ASSD GTY, 5.25%, 7/01/2041		310,000	349,274
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “L”, NATL, 5.25%, 7/01/2035		120,000	130,171
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “N”, AAC, 5.5%, 7/01/2029		330,000	367,112
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “N”, AAC, 5.25%, 7/01/2031		240,000	263,016
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “N”, ASSD GTY, 5.25%, 7/01/2036		5,000	5,653
Commonwealth of Puerto Rico Highway & Transportation Authority Rev., “N”, NATL, 5.25%, 7/01/2032		35,000	38,224
Metropolitan Transportation Authority Rev., NY, Green Transportation Rev., Bidding Group 1 (Climate Bond Certified), “C”, BAM, 5%, 11/15/2043		535,000	652,277
New Jersey Transportation Trust Fund Authority, Federal Highway Reimbursement Rev., “A-1”, 5%, 6/15/2027		105,000	123,943
New Jersey Transportation Trust Fund Authority, Transportation System, Capital Appreciation, “C”, AGM, 0%, 12/15/2029		280,000	217,832
			$3,392,145

3

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Universities - Colleges – 20.3%
Alabama Community College System Board of Trustees Rev. (Bishop State Community College), BAM, 4%, 1/01/2044	$	300,000	$330,336
Alabama Community College System Board of Trustees Rev. (Bishop State Community College), BAM, 4%, 1/01/2049		1,000,000	1,094,030
Alabama Community College System Board of Trustees Rev. (Snead State Community College), BAM, 4%, 9/01/2038		680,000	761,070
Alabama State University Board of Education Rev. (Chattahoochee Valley Community College), ASSD GTY, 5%, 6/01/2034		1,300,000	1,303,432
Auburn University, General Fee Rev., “A”, 5%, 6/01/2038		500,000	591,660
Auburn University, General Fee Rev., “A”, 5%, 6/01/2048		1,500,000	1,811,715
Homewood, AL, Educational Building Authority Facilities Rev. (Samford University), “A”, 5%, 12/01/2034		500,000	590,255
Jacksonville, AL, Public Educational Building Authority Higher Education Facilities Rev. (Jacksonville State University Foundation), “A”, 5%, 7/01/2036		600,000	710,694
Puerto Rico Industrial, Tourist, Educational, Medical & Environmental Control Facilities Financing Authority, Educational Facilities Rev. (University Plaza Project), NATL, 5%, 7/01/2033		65,000	65,720
Troy University, Facilities Rev., “A”, BAM, 5%, 11/01/2028		500,000	583,865
University of Alabama at Birmingham, Rev., “B”, 4%, 10/01/2037		1,000,000	1,146,110
University of Alabama in Huntsville, General Fee Rev., 4%, 6/01/2035		1,000,000	1,163,070
University of Alabama in Huntsville, General Fee Rev., “B2”, 5%, 9/01/2035		755,000	943,606
University of Alabama in Huntsville, General Fee Rev., “B2”, 5%, 9/01/2036		475,000	592,002
University of Alabama, General Rev., “C”, 4%, 7/01/2035		1,250,000	1,445,750
University of North Alabama, General Fee Rev., “B”, BAM, 5%, 11/01/2039		1,000,000	1,222,310
University of North Alabama, General Fee Rev., “C”, BAM, 4%, 11/01/2038		500,000	558,555
University of South Alabama, Facilities Rev., BAM, 5%, 10/01/2036		500,000	601,745
University of South Alabama, Facilities Rev., “A”, BAM, 5%, 4/01/2049		750,000	905,062
			$16,420,987
Utilities - Municipal Owned – 2.5%
Chatom, AL, Industrial Development Board Gulf Opportunity Zone (PowerSouth Energy), “A”, ASSD GTY, 5%, 8/01/2037	$	1,000,000	$1,018,820
Guam Power Authority Rev., “A”, 5.5%, 10/01/2040 (Prerefunded 10/01/2020)		230,000	237,443
Puerto Rico Electric Power Authority Rev., “A”, 5%, 7/01/2029 (a)(d)		175,000	132,562
Puerto Rico Electric Power Authority Rev., “A”, 5%, 7/01/2042 (a)(d)		30,000	22,725
Puerto Rico Electric Power Authority Rev., “CCC”, 5.25%, 7/01/2027 (a)(d)		50,000	38,000
Puerto Rico Electric Power Authority Rev., “DDD”, 5%, 7/01/2021 (a)(d)		60,000	45,450
Puerto Rico Electric Power Authority Rev., “DDD”, 5%, 7/01/2022 (a)(d)		115,000	87,112
Puerto Rico Electric Power Authority Rev., “DDD”, AGM, 3.625%, 7/01/2023		10,000	10,001
Puerto Rico Electric Power Authority Rev., “DDD”, AGM, 3.65%, 7/01/2024		50,000	50,009
Puerto Rico Electric Power Authority Rev., “SS”, ASSD GTY, 4.375%, 7/01/2030		10,000	10,025
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2023 (a)(d)		30,000	22,725
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2037 (a)(d)		95,000	71,963
Puerto Rico Electric Power Authority Rev., “UU”, ASSD GTY, 4.25%, 7/01/2027		70,000	70,144
Puerto Rico Electric Power Authority Rev., “V”, NATL, 5.25%, 7/01/2033		35,000	37,816
Puerto Rico Electric Power Authority Rev., “VV”, NATL, 5.25%, 7/01/2032		105,000	114,673
Puerto Rico Electric Power Authority Rev., “VV”, NATL, 5.25%, 7/01/2034		15,000	16,374
Puerto Rico Electric Power Authority Rev., “ZZ”, 5%, 7/01/2022 (a)(d)		40,000	29,600
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2023 (a)(d)		50,000	38,000
			$2,053,442
Utilities - Other – 0.1%
Central Plains Energy Project, NE, Gas Project Rev. (Project No. 3), “A”, 5%, 9/01/2036	$	40,000	$52,774
Water & Sewer Utility Revenue – 11.2%
Auburn, AL, Waterworks Board Water Rev., 5%, 9/01/2036	$	1,000,000	$1,168,910
Birmingham, AL, Waterworks Board Water Rev., 5%, 1/01/2036		750,000	911,970
Birmingham, AL, Waterworks Board Water Rev., “A”, 5%, 1/01/2030		500,000	592,375
Commonwealth of Puerto Rico Aqueduct & Sewer Authority Rev., “A”, ASSD GTY, 5%, 7/01/2028		10,000	10,263
Cullman, AL, Utilities Board Water Rev., “A”, AGM, 5%, 9/01/2035		1,000,000	1,151,960
Gadsden, AL, Water Works and Sewer Rev., AGM, 4%, 6/01/2033		1,000,000	1,116,650
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 7/01/2036		45,000	51,458
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 1/01/2046		120,000	134,847
Guam Waterworks Authority Rev. (Water and Wastewater System), “A”, 5%, 7/01/2029		45,000	50,310
Guam Waterworks Authority Rev. (Water and Wastewater System), “A”, 5%, 7/01/2035		45,000	49,661
Jefferson County, AL, Senior Lien Sewer Rev., Current Interest Warrants, “A”, AGM, 5%, 10/01/2044		750,000	840,045

4

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Water & Sewer Utility Revenue – continued
Jefferson County, AL, Sewer Rev. Warrants, Subordinate Lien, “D”, 5%, 10/01/2021	$	300,000	$317,784
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		15,000	17,037
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		20,000	22,589
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		10,000	11,354
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		20,000	22,583
Prichard City, AL, Water Works & Sewer Board Water Rev., 4%, 11/01/2044		700,000	735,931
Scottsboro, AL, Waterworks Sewer & Gas Board Rev., 5%, 8/01/2032		500,000	539,965
Warrior River, AL, Water Authority Rev., BAM, 4%, 8/01/2039		1,180,000	1,329,376
			$9,075,068
Total Municipal Bonds			$78,150,842
Bonds – 0.1%
Consumer Services – 0.1%
Toll Road Investors Partnership II LP, Capital Appreciation, NATL, 0%, 2/15/2043 (n)	$	200,000	$58,433
Investment Companies (h) – 2.5%
Money Market Funds – 2.5%
MFS Institutional Money Market Portfolio, 1.7% (v)		2,051,554	$2,051,554
Other Assets, Less Liabilities – 1.0%			779,057
Net Assets – 100.0%			$81,039,886

(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 $2,051,554 and $78,209,275, 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 $58,433, representing 0.1% 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.

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
ETM	Escrowed to Maturity
NATL	National Public Finance Guarantee Corp.

Derivative Contracts at 12/31/19
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	18	$2,806,313	March – 2020	$72,812

At December 31, 2019, the fund had cash collateral of $48,600 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.

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Supplemental Information

12/31/19 (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, 2019 in valuing the fund's assets or liabilities:

Financial Instruments	Level 1	Level 2	Level 3	Total
Municipal Bonds	$—	$78,150,842	$—	$78,150,842
U.S. Corporate Bonds	—	58,433	—	58,433
Mutual Funds	2,051,554	—	—	2,051,554
Total	$2,051,554	$78,209,275	$—	$80,260,829
Other Financial Instruments
Futures Contracts – Assets	$72,812	$—	$—	$72,812

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	$267,171	$24,784,564	$23,000,055	$(169)	$43	$2,051,554

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Supplemental Information (unaudited) – continued

Affiliated Issuers	Dividend Income	Capital Gain Distributions
MFS Institutional Money Market Portfolio	$32,820	$—

(3) Jurisdiction Weightings

Jurisdiction weighting percentages based on net assets, as of December 31, 2019, are as follows:

Alabama	78.4%
Puerto Rico	6.6%
New York	2.7%
Illinois	2.0%
California	1.5%
Colorado	0.9%
Guam	0.9%
Massachusetts	0.9%
South Carolina	0.8%
Florida	0.6%
New Jersey	0.5%
Pennsylvania	0.5%
Virginia	0.4%
Maryland	0.3%
Indiana	0.2%
Iowa	0.2%
Texas	0.2%
Michigan	0.1%
Nebraska	0.1%

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

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