FundWatcher
MFSSX
MFS Massachusetts Municipal Bond Fund
MFS Municipal Series Trust

Portfolio concentration

As of March 31, 2026 · N-PORT
Holdings
269
Top-10 weight
11.78%
Effective holdings ?
170
Crowding ?
20.0

Holdings

As of March 31, 2026 · N-PORT
#SecurityTickerSharesValue% of fund
1 MFS Institutional Money Market Portfolio, Class A — 6,780,076 $6.78M 1.66%
2 MASSACHUSETTS ST DEV FIN AGY R REGD B/E 5.00000000 MASDEV 5,000,000 $5.52M 1.35%
3 Commonwealth of Massachusetts Transportation Fund, Series 2025A — 5,000,000 $5.25M 1.28%
4 MASSACHUSETTS ST DEV FIN AGY REVENUE — 5,000,000 $5.02M 1.23%
5 MA CLEAN WTR TRUST-27 — 4,000,000 $4.24M 1.04%
6 MBTA SLS TAX 5.25% 7/1/55 — 4,000,000 $4.20M 1.03%
7 MASSACHUSETTS ST — 4,000,000 $4.17M 1.02%
8 MASSACHUSETTS ST SCH BLDG AUTH SALES TAX REVENUE MASEDU 4,000,000 $4.16M 1.02%
9 MASSACHUSETTS ST SCH BLDG AUTH SALES TAX REVENUE — 4,000,000 $4.14M 1.01%
10 MA ST TRANS REV 5% 6/1/2053 — 4,000,000 $4.13M 1.01%
11 Tri-County Regional Vocational Technical School District, Series CHAPTER 70B — 4,000,000 $3.90M 0.95%
12 MASS DEVEL FIN 4% 10/1/2045 — 4,075,000 $3.68M 0.90%
13 PUERTO RICO SALES TAX FING COR REGD OID B/E 5.00000000 PRCGEN 3,806,000 $3.62M 0.89%
14 MASSACHUSETTS ST DEV FIN AGY REVENUE — 3,500,000 $3.61M 0.88%
15 MASSACHUSETTS ST PORT AUTH — 3,455,000 $3.60M 0.88%
16 Massachusetts Development Finance Agency, Series 2025W — 3,850,000 $3.58M 0.88%
17 Town of Tisbury — 5,000,000 $3.58M 0.87%
18 Massachusetts Housing Finance Agency — 3,320,000 $3.52M 0.86%
19 Massachusetts Bay Transportation Authority, Series 2025 B — 3,000,000 $3.22M 0.79%
20 Massachusetts Educational Financing Authority — 4,000,000 $3.19M 0.78%
21 WAKEFIELD MA REGD B/E 5.00000000 — 3,000,000 $3.16M 0.77%
22 Massachusetts Development Finance Agency — 3,015,000 $3.14M 0.77%
23 MASSACHUSETTS ST DEV FIN AGY REVENUE — 3,000,000 $3.13M 0.77%
24 MA ST TRANS REV 5% 6/1/2049 — 3,000,000 $3.11M 0.76%
25 MASS DEVEL FIN 5% 7/1/2048 — 3,115,000 $3.11M 0.76%
26 MASSACHUSETTS ST PORT AUTH REGD B/E AMT 5.00000000 — 3,055,000 $3.07M 0.75%
27 MASSACHUSETTS ST — 3,000,000 $3.06M 0.75%
28 MASSACHUSETTS ST PORT AUTH — 3,000,000 $3.05M 0.75%
29 MASSACHUSETTS ST TRANSPRTN FUND REVENUE MASTRN 3,000,000 $3.05M 0.75%
30 MASSACHUSETTS ST DEV FIN AGY R REGD B/E 5.50000000 — 3,000,000 $3.05M 0.75%
31 MASSACHUSETTS ST DEV FIN AGY R REGD B/E 5.00000000 MASDEV 3,000,000 $3.04M 0.74%
32 Massachusetts Housing Finance Agency — 3,000,000 $3.03M 0.74%
33 Massachusetts Port Authority, Revenue Bonds, Refunding Series 2017A — 3,000,000 $3.02M 0.74%
34 Massachusetts (Commonwealth of), Series 2024 E, GO Bonds — 2,930,000 $3.01M 0.74%
35 Massachusetts Housing Finance Agency, Series 2013B — 3,000,000 $3.00M 0.73%
36 Massachusetts Housing Finance Agency, Series 249 — 3,000,000 $2.98M 0.73%
37 S E ENERGY COOP DT — 2,720,000 $2.93M 0.72%
38 MA ST DEV FIN -J2 — 2,855,000 $2.89M 0.71%
39 Nashoba Regional School District — 3,010,000 $2.88M 0.71%
40 Commonwealth of Massachusetts Transportation Fund Revenue — 2,850,000 $2.86M 0.70%
41 Massachusetts Development Finance Agency 4.00% 07/01/2039 MASDEV 3,055,000 $2.85M 0.70%
42 MASSACHUSETTS ST PORT AUTH — 2,755,000 $2.83M 0.69%
43 Town of Hingham, Series 2025 — 3,020,000 $2.81M 0.69%
44 NEW BEDFORD MA — 3,000,000 $2.77M 0.68%
45 MASSACHUSETTS ST DEV FIN AGY REVENUE — 2,665,000 $2.77M 0.68%
46 MASSACHUSETTS ST DEV FIN AGY REVENUE — 2,845,000 $2.72M 0.67%
47 MA ST DEV FIN AGY-N MASDEV 2,690,000 $2.71M 0.66%
48 Massachusetts Housing Finance Agency, Single Family Housing Revenue Bonds, Social Series 2024-234 — 2,750,000 $2.71M 0.66%
49 Massachusetts Development Finance Agency — 2,550,000 $2.62M 0.64%
50 CALIFORNIA ST HLTH FACS FING AUTH REVENUE CASMED 2,405,000 $2.49M 0.61%
1 / 6 Next ›

Machine-readable: JSON · Markdown. Programmatic access via the agent surface.