MFS Municipal Income R6 (MPMNX) NPORT-P MFS West Virginia Municipal Bond Fund (Dec 2024 report)

Quarterly Report

December 31, 2024

MFS^®West Virginia
Municipal Bond Fund

MWV-Q3

Portfolio of Investments

12/31/24 (unaudited)

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

Issuer		Shares/Par	Value ($)
Municipal Bonds – 98.3%
Airport Revenue – 0.7%
New York Transportation Development Corp., Special Facilities Rev. (John F. Kennedy International Airport New Terminal One Project), AGM, 5.25%, 6/30/2060	$	445,000	$463,840
Wayne County, MI, Airport Authority Rev. (Detroit Metropolitan Wayne County Airport), “B”, 5%, 12/01/2044		60,000	60,033
Wayne County, MI, Airport Authority Rev. (Detroit Metropolitan Wayne County Airport), “C”, 5%, 12/01/2039		55,000	55,017
Wayne County, MI, Airport Authority Rev. (Detroit Metropolitan Wayne County Airport), “C”, 5%, 12/01/2044		85,000	85,022
			$663,912
General Obligations - General Purpose – 5.8%
Bridgeview, IL, Stadium and Redevelopment Projects, Taxable, AAC, 5.14%, 12/01/2036	$	260,000	$232,590
Chicago, IL, General Obligation, “A”, 5.5%, 1/01/2040		360,000	380,447
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, “A”, 5.625%, 7/01/2029		44,227	47,112
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, “A”, 5.75%, 7/01/2031		42,958	46,979
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, “A”, 4%, 7/01/2033		40,735	40,116
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, “A”, 4%, 7/01/2035		74,630	72,752
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, “A”, 4%, 7/01/2037		31,426	30,305
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, “A”, 4%, 7/01/2041		42,727	40,399
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, “A”, 4%, 7/01/2046		143,435	133,199
Commonwealth of Puerto Rico, General Obligation Restructured Bonds, Capital Appreciation, “A”, 0%, 7/01/2033		52,422	35,462
State of Illinois, General Obligation, 5.5%, 5/01/2039		165,000	177,714
State of Illinois, General Obligation, “C”, 4%, 10/01/2040		155,000	151,150
State of Illinois, General Obligation, “C”, 4%, 10/01/2041		70,000	67,707
State of West Virginia, General Obligation Road Bonds, “A”, 5%, 12/01/2043		1,000,000	1,044,288
State of West Virginia, General Obligation Road Bonds, “A”, 5%, 6/01/2044		2,000,000	2,085,443
State of West Virginia, General Obligation Road Bonds, “A”, 5%, 12/01/2044		705,000	750,221
			$5,335,884
General Obligations - Schools – 5.1%
Berkeley County, WV, Public School Board of Education, 3%, 6/01/2026	$	750,000	$748,037
Berkeley County, WV, Public School Board of Education, 4%, 6/01/2037		1,000,000	1,016,128
Cabell County, WV, Public School Board of Education, AGM, 3%, 6/01/2029		1,000,000	983,475
Little Rock, AR, School District & Construction, “A”, BAM, 3%, 2/01/2048		820,000	627,504
Orange County, CA, Anaheim Elementary School District, AGM, 4%, 8/01/2048		310,000	310,480
Wood County, WV, Public School Board of Education, 4%, 6/01/2039		1,000,000	1,003,427
			$4,689,051
Healthcare Revenue - Hospitals – 14.4%
Allegheny County, PA, Hospital Development Authority Rev. (Allegheny Health Network Obligated Group), “A”, 4%, 4/01/2044	$	155,000	$145,629
Doylestown, PA, Hospital Authority Rev., “A”, 4%, 7/01/2045 (Prerefunded 7/01/2029)		5,000	5,166
Doylestown, PA, Hospital Authority Rev., “A”, 4%, 7/01/2045		10,000	9,144
Virginia Small Business Financing Authority, Health Facilities Rev. (Bon Secours Mercy Health, Inc.), “A”, 4%, 12/01/2049		490,000	469,544
West Virginia Hospital Finance Authority Hospital Rev. (Cabell Huntington Hospital Obligated Group), 4%, 1/01/2038		230,000	213,965
West Virginia Hospital Finance Authority Hospital Rev. (Cabell Huntington Hospital Obligated Group), “A”, 4.125%, 1/01/2047		1,245,000	1,091,844
West Virginia Hospital Finance Authority Hospital Rev. (Charleston Area Medical Center, Inc.), “A”, 5%, 9/01/2028		1,000,000	1,000,905
West Virginia Hospital Finance Authority Hospital Rev. (Charleston Area Medical Center, Inc.), “A”, 5%, 9/01/2039		1,500,000	1,529,219
West Virginia Hospital Finance Authority Hospital Rev. (Valley Health System Obligation Group), 5%, 1/01/2044		1,000,000	1,004,961
West Virginia Hospital Finance Authority Hospital Rev. (Vandalia Health Group), “B”, 5.5%, 9/01/2048		1,000,000	1,090,895
West Virginia Hospital Finance Authority Hospital Rev. (West Virginia United Health System Obligated Group), “A”, 5%, 6/01/2027		200,000	204,841
West Virginia Hospital Finance Authority Hospital Rev. (West Virginia United Health System Obligated Group), “A”, 4%, 6/01/2035		1,500,000	1,502,131
West Virginia Hospital Finance Authority Hospital Rev. (West Virginia University Health System Obligated Group), “A”, 5%, 6/01/2042		1,000,000	1,018,229
West Virginia Hospital Finance Authority Hospital Rev. (West Virginia University Health System Obligated Group), “A”, 4%, 6/01/2051		860,000	802,800
West Virginia Hospital Finance Authority Hospital Rev. (West Virginia University Health System Obligated Group), “A”, 4.375%, 6/01/2053		1,000,000	967,390

1

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Healthcare Revenue - Hospitals – continued
West Virginia Hospital Finance Authority Hospital Rev. (West Virginia University Health System Obligated Group), “A”, AGM, 4%, 6/01/2051	$	2,220,000	$2,085,514
			$13,142,177
Industrial Revenue - Environmental Services – 0.2%
Pennsylvania Economic Development Financing Authority, Solid Waste Disposal Rev. (Waste Management, Inc. Project), 4.25%, 7/01/2041 (Put Date 7/01/2027)	$	180,000	$180,555
Industrial Revenue - Other – 0.3%
Port Beaumont, TX, Navigation District, Dock & Wharf Facility Rev. (Jefferson Gulf Coast Energy Project), “A”, 2.875%, 1/01/2041 (n)	$	115,000	$90,097
Port Beaumont, TX, Navigation District, Dock & Wharf Facility Rev. (Jefferson Gulf Coast Energy Project), “A”, 4%, 1/01/2050 (n)		200,000	167,039
			$257,136
Miscellaneous Revenue - Other – 6.5%
Matching Fund Special Purpose Securitization Corp., “A”, 5%, 10/01/2026	$	40,000	$40,851
Morgantown, WV, Building Commission Leave Rev. (Marilla Park Aquatic Complex), “A”, 4.25%, 12/01/2043		790,000	765,665
Morgantown, WV, Building Commission Leave Rev. (Marilla Park Aquatic Complex), “A”, 4.5%, 12/01/2048		540,000	526,403
New York Liberty Development Corp., Liberty Rev. (3 World Trade Center Project), “1”, 5%, 11/15/2044 (n)		580,000	580,330
West Virginia Economic Development Authority, Excess Lottery Rev., “A”, 5%, 7/01/2038		1,000,000	1,044,414
West Virginia School Building Authority, “A”, 3%, 7/01/2033		2,000,000	1,901,737
West Virginia School Building Authority, Excess Lottery Refunding Rev., “B”, 5%, 7/01/2038		265,000	288,534
West Virginia School Building Authority, Excess Lottery Refunding Rev., “B”, 5%, 7/01/2039		735,000	797,397
			$5,945,331
Multi-Family Housing Revenue – 0.3%
National Finance Authority, NH, Municipal Certificates, “1-A”, 4.375%, 9/20/2036	$	279,237	$277,307
San Antinio, TX, Housing Trust Public Facility Corp., Multifamily (Cedar Ridge Terrace Apartments), “A”, FNMA, 4.45%, 4/01/2043		35,000	34,596
			$311,903
Port Revenue – 0.1%
New York Liberty Development Corp., Liberty Refunding Rev. (1 World Trade Center Project), 2.75%, 2/15/2044	$	170,000	$128,041
Sales & Excise Tax Revenue – 4.5%
Guam Government Business Privilege Tax Refunding, “F”, 4%, 1/01/2042	$	75,000	$71,266
Monongalia County, WV, Commission Special District Excise Tax Refunding & Improvement Rev. (University Town Centre Economic Opportunity Development District), “A”, 4.125%, 6/01/2043 (n)		930,000	824,640
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “2019A-2”, 4.536%, 7/01/2053		1,000	975
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “A-1”, 4.55%, 7/01/2040		25,000	25,006
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “A-1”, 4.75%, 7/01/2053		83,000	81,761
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “A-1”, 5%, 7/01/2058		2,079,000	2,071,226
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “A-2”, 4.329%, 7/01/2040		158,000	155,834
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “A-2”, 4.329%, 7/01/2040		83,000	82,046
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., “A-2”, 4.784%, 7/01/2058		39,000	38,302
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “A-1”, 0%, 7/01/2029		7,000	5,873
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “A-1”, 0%, 7/01/2031		412,000	316,673
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “A-1”, 0%, 7/01/2033		396,000	278,830
Puerto Rico Sales Tax Financing Corp., Restructured Sales Tax Rev., Capital Appreciation, “A-1”, 0%, 7/01/2046		186,000	59,833
Wisconsin Public Finance Authority Limited Obligation Grant Rev. (American Dream at Meadowlands Project), “A”, 6.25%, 8/01/2027 (a)(d)(n)		120,000	116,100
			$4,128,365
Single Family Housing - State – 14.3%
West Virginia Housing Development Fund, “A”, 4.55%, 11/01/2049	$	1,000,000	$988,126
West Virginia Housing Development Finance, “D”, 4.45%, 11/01/2049		1,000,000	979,244
West Virginia Housing Development Fund, “A”, 3.875%, 11/01/2044		1,120,000	1,030,201
West Virginia Housing Development Fund, “A”, 4.75%, 11/01/2048		1,000,000	1,007,913
West Virginia Housing Development Fund, “B”, 1.8%, 5/01/2026		485,000	467,989
West Virginia Housing Development Fund, “B”, 4.7%, 11/01/2044		1,000,000	1,015,290

2

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Single Family Housing - State – continued
West Virginia Housing Development Fund, “B”, 4.2%, 11/01/2047	$	1,000,000	$965,994
West Virginia Housing Development Fund, “B”, 4.25%, 11/01/2052		615,000	580,034
West Virginia Housing Development Fund, “B”, 4.7%, 11/01/2053		980,000	983,379
West Virginia Housing Development Fund, “C”, 4.45%, 11/01/2037		1,000,000	1,007,997
West Virginia Housing Development Fund, “C”, 4.625%, 11/01/2042		1,000,000	999,192
West Virginia Housing Development Fund, “C”, 4.8%, 11/01/2047		1,000,000	1,015,763
West Virginia Housing Development Fund, “D”, 4.6%, 11/01/2043		1,000,000	1,006,191
West Virginia Housing Development Fund, “D”, 4.8%, 11/01/2048		1,000,000	1,015,561
			$13,062,874
State & Local Agencies – 10.4%
Berkeley County, WV, Building Commission Lease Rev. (Berkeley County Day Report Center and Public Safety Building Projects), 4%, 12/01/2042	$	1,740,000	$1,699,553
Fayette County, WV, Board of Education, 4%, 7/01/2034		500,000	500,515
Fayette County, WV, Board of Education, 4%, 7/01/2035		500,000	498,185
North Carolina Turnpike Authority, Triangle Expressway System Appropriation Rev., Capital Appreciation, 0%, 1/01/2044		1,640,000	699,516
Parkersburg, WV, Municipal Building Commission Lease Rev. (Recreation Facility and Fire Station Projects), 4.375%, 11/01/2054		850,000	812,434
Putnam County, WV, Building Commission Lease Rev. (Sheriff's Headquarters), “A”, BAM, 4.25%, 5/01/2042		500,000	501,864
Putnam County, WV, Building Commission Lease Rev. (Sheriff's Headquarters), “A”, BAM, 4.25%, 5/01/2047		500,000	495,427
Putnam County, WV, Building Commission Lease Rev. (Sheriff's Headquarters), “A”, BAM, 4.375%, 5/01/2052		560,000	544,226
West Virginia Economic Development Authority, Lease Rev. (Correctional, Juvenile and Public Safety Facilities), “A”, 5%, 6/01/2029		1,500,000	1,502,298
West Virginia Economic Development Authority, Lease Rev. (State Office Building), “B”, NPFG, 5.25%, 1/01/2025		115,000	115,000
West Virginia Economic Development Authority, Lease Rev. (State Office Building), “B”, NPFG, 5.25%, 1/01/2030		1,355,000	1,357,367
West Virginia Hospital Finance Authority Hospital Rev. (Veterans Nursing Home), 5.5%, 3/01/2034		795,000	795,935
			$9,522,320
Student Loan Revenue – 0.4%
New Jersey Higher Education Student Assistance Authority, Senior Student Loan Rev., “B”, 4%, 12/01/2041	$	380,000	$373,425
Tax - Other – 3.5%
Chicago, IL, Board of Education, Dedicated Capital Improvement Tax Bond, 5%, 4/01/2045	$	65,000	$66,812
Chicago, IL, Board of Education, Dedicated Capital Improvement Tax Bond, 5.75%, 4/01/2048		175,000	187,857
Monongalia County, WV, Senior Tax Increment Improvement Refunding Rev. (Development District No. 4 - University Town Centre), “A”, 6%, 6/01/2053 (n)		875,000	933,796
Ohio County, WV, Tax Increment Rev., 5.25%, 6/01/2053		1,000,000	1,017,194
Virgin Islands Public Finance Authority Rev. (Gross Receipts), AGM, 5%, 10/01/2032		1,000,000	1,009,807
			$3,215,466
Tax Assessment – 0.5%
Morgantown, WV, Tax Increment Rev., Parking Garage Project, “A”, 5%, 6/01/2033	$	455,000	$436,075
Tobacco – 0.7%
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020A-2, “1”, 4%, 6/01/2048	$	125,000	$108,876
Buckeye, OH, Tobacco Settlement Financing Authority Senior Asset-Backed Refunding, 2020B-2, “2”, 5%, 6/01/2055		320,000	283,601
Golden State, CA, Tobacco Securitization Corp., Tobacco Settlement Rev., Taxable, “B-1”, 3.85%, 6/01/2050		270,000	244,531
			$637,008
Toll Roads – 2.4%
Virginia Small Business Financing Authority Senior Lien Rev. (Elizabeth River Crossings Opco LLC Project), 3%, 1/01/2041	$	325,000	$262,452
West Virginia Parkways Authority, Senior Lien Turnpike Toll Rev., 4%, 6/01/2042		1,000,000	983,445
West Virginia Parkways Authority, Turnpike Toll Rev., 4%, 6/01/2047		1,000,000	954,423
			$2,200,320
Transportation - Special Tax – 1.0%
New Jersey Transportation Trust Fund Authority, “AA”, 4%, 6/15/2050	$	1,000,000	$950,749

3

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Municipal Bonds – continued
Universities - Colleges – 9.0%
Fairmont, WV, State University Board of Governors Refunding Rev., “A”, 5%, 6/01/2032	$	1,050,000	$1,137,861
Marshall University, WV, Board of Governors Rev., “A”, AGM, 3%, 5/01/2046		1,000,000	779,746
Marshall University, WV, Board of Governors Rev., “A”, AGM, 4%, 5/01/2050		1,500,000	1,342,961
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		90,000	90,106
West Virginia University, Board of Governors Improvement Rev. (West Virginia University Project), “A”, 5%, 10/01/2044		1,000,000	1,062,186
West Virginia University, Board of Governors Improvement Rev. (West Virginia University Project), “A”, 5%, 10/01/2049		2,000,000	2,073,611
West Virginia University, University Systems Rev., “A”, NPFG, 5.25%, 4/01/2028		1,665,000	1,706,841
			$8,193,312
Universities - Dormitories – 1.2%
West Virginia Economic Development Authority, University Facilities Refunding Rev. (Provident Group - Marshall Properties LLC - Marshall University Project), “A-1”, AGM, 5%, 7/01/2042	$	1,000,000	$1,061,107
Utilities - Investor Owned – 2.9%
West Virginia Economic Development Authority, Solid Waste Disposal Facilities Refunding Rev. (Wheeling Power Co. - Mitchell Project), “A”, 3%, 6/01/2037 (Put Date 6/18/2027)	$	1,000,000	$976,736
West Virginia Economic Development Authority, Solid Waste Disposal Facilities Rev. (Appalachian Power Company - Amos Project), “A”, 0.625%, 12/01/2038 (Put Date 12/15/2025)		750,000	719,554
West Virginia Economic Development Authority, Solid Waste Disposal Facilities Rev. (Appalachian Power Company - Amos Project), “A”, 1%, 1/01/2041 (Put Date 9/01/2025)		1,000,000	974,670
			$2,670,960
Utilities - Municipal Owned – 0.6%
Puerto Rico Electric Power Authority Rev., “A”, 5%, 7/01/2029 (a)(d)	$	285,000	$153,900
Puerto Rico Electric Power Authority Rev., “CCC”, 5.25%, 7/01/2027 (a)(d)		100,000	54,000
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2021 (a)(d)		40,000	21,600
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2023 (a)(d)		50,000	27,000
Puerto Rico Electric Power Authority Rev., “TT”, 5%, 7/01/2037 (a)(d)		145,000	78,300
Puerto Rico Electric Power Authority Rev., “VV”, NPFG, 5.25%, 7/01/2030		135,000	133,371
Puerto Rico Electric Power Authority Rev., “VV”, NPFG, 5.25%, 7/01/2034		10,000	9,844
Puerto Rico Electric Power Authority Rev., “ZZ”, 5.25%, 7/01/2023 (a)(d)		75,000	40,500
Puerto Rico Electric Power Authority Rev., Taxable, “EEE”, 6.05%, 7/01/2032 (a)(d)		50,000	27,000
			$545,515
Utilities - Other – 2.9%
Black Belt Energy Gas District, AL, Gas Project Rev., “A”, 4%, 6/01/2051 (Put Date 12/01/2031)	$	280,000	$280,034
Black Belt Energy Gas District, AL, Gas Project Rev., “C-1”, 5.25%, 2/01/2053 (Put Date 6/01/2029)		565,000	593,530
California Community Choice Financing Authority, Clean Energy Project Rev., “C”, 5.25%, 1/01/2054 (Put Date 10/01/2031)		560,000	594,881
Southeast Alabama Energy Authority Commodity Supply Rev. (Project No. 5), “A”, 5.25%, 1/01/2054 (Put Date 7/01/2029)		510,000	537,033
Southeast Alabama Energy Authority Energy Supply Rev., “A”, 5%, 11/01/2035		315,000	326,526
Tennergy Corp., TN, Gas Supply Rev., “A”, 5.5%, 10/01/2053 (Put Date 12/01/2030)		310,000	331,021
			$2,663,025
Water & Sewer Utility Revenue – 10.6%
Berkeley County, WV, Public Service Sewer District, “A”, BAM, 5%, 6/01/2036	$	1,700,000	$1,732,394
Greenbrier County, WV, Public Service District No. 1, Sewerage System Improvement Rev., “A”, BAM, 4.625%, 10/01/2052		1,000,000	1,003,108
Guam Waterworks Authority Rev. (Water and Wastewater System), 5%, 1/01/2046		180,000	181,656
Guam Waterworks Authority Rev. (Water and Wastewater System), “A”, 5%, 1/01/2050		135,000	138,647
Mississippi Development Bank Special Obligation (Jackson Water and Sewer System Rev. Bond Project), AGM, 6.875%, 12/01/2040		75,000	76,268
Morgantown, WV, Combined Utility System Rev., “A”, AGM, 5%, 12/01/2041		1,000,000	1,024,142
Morgantown, WV, Combined Utility System Rev., “B”, 5%, 12/01/2043		2,000,000	2,064,627
West Virginia Water Development Authority Rev. (Loan Program II), “A-II”, 5%, 11/01/2033		1,475,000	1,507,405
West Virginia Water Development Authority Rev. (Loan Program IV), “A-IV”, 5%, 11/01/2038		500,000	517,865
Wheeling, WV, Combined Waterworks and Sewerage System Rev., “A”, BAM, 4%, 6/01/2051		1,500,000	1,429,458
			$9,675,570
Total Municipal Bonds			$89,990,081

4

Portfolio of Investments (unaudited) – continued

Issuer		Shares/Par	Value ($)
Bonds – 0.3%
Transportation - Services – 0.3%
Toll Road Investors Partnership II LP, Capital Appreciation, NPFG, 0%, 2/15/2025 (n)	$	167,000	$165,837
Toll Road Investors Partnership II LP, Capital Appreciation, NPFG, 0%, 2/15/2043 (n)		363,682	105,468
Total Bonds			$271,305
Contingent Value Instruments – 0.1%
General Obligations - General Purpose – 0.1%
Commonwealth of Puerto Rico, General Obligation Contingent Value Instrument, 11/01/2043	$	168,529	$103,224
Mutual Funds (h) – 0.3%
Money Market Funds – 0.3%
MFS Institutional Money Market Portfolio, 4.49% (v)		245,662	$245,711
Other Assets, Less Liabilities – 1.0%			956,767
Net Assets – 100.0%			$91,567,088

(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 $245,711 and $90,364,610, 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 $2,983,307, representing 3.3% 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.

The following abbreviations are used in this report and are defined:
AAC	Ambac Assurance Corp.
AGM	Assured Guaranty Municipal
BAM	Build America Mutual
FNMA	Federal 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.

5

Supplemental Information

12/31/24 (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. Pricing services generally value debt instruments assuming orderly transactions of institutional round lot sizes, but a fund may hold or transact in such securities in smaller, odd lot sizes. Odd lots may trade at lower prices than institutional round lots, and the fund may receive different prices when it sells odd lot positions than it would receive for sales of institutional round lot positions. 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, 2024 in valuing the fund's assets and liabilities:

Financial Instruments	Level 1	Level 2	Level 3	Total
Municipal Bonds	$—	$90,093,305	$—	$90,093,305
U.S. Corporate Bonds	—	271,305	—	271,305
Investment Companies	245,711	—	—	245,711
Total	$245,711	$90,364,610	$—	$90,610,321

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

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Supplemental Information (unaudited) – continued

(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 for the period ended December 31, 2024:

Affiliated Issuers	Beginning Value	Purchases	Sales Proceeds	Realized Gain (Loss)	Change in Unrealized Appreciation or Depreciation	Ending Value
MFS Institutional Money Market Portfolio	$734,986	$14,327,762	$14,817,574	$676	$(139)	$245,711

Affiliated Issuers	Dividend Income	Capital Gain Distributions
MFS Institutional Money Market Portfolio	$76,112	$—

(3) Jurisdiction Weightings

Jurisdiction weighting percentages based on net assets, as of December 31, 2024, are as follows:

West Virginia	81.1%
Puerto Rico	4.8%
Alabama	1.9%
New Jersey	1.5%
Illinois	1.4%
California	1.3%
New York	1.3%
U.S. Virgin Islands	1.2%
Virginia	1.1%
North Carolina	0.8%
Arkansas	0.7%
Guam	0.4%
Ohio	0.4%
Pennsylvania	0.4%
Tennessee	0.4%
New Hampshire	0.3%
Texas	0.3%
Michigan	0.2%
Mississippi	0.1%
Wisconsin	0.1%

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

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