{
  "page": "compare",
  "query": {
    "a": "MBMAX",
    "b": "MFSMX"
  },
  "retrieved_at": "2026-07-07T19:06:25+00:00",
  "disclaimer": "Informational only — not investment advice. FundWatcher presents publicly available data and makes no recommendation to buy or sell any security. Verify all figures against the source filing before relying on them.",
  "attribution": "Data sourced from U.S. SEC EDGAR filings (Forms N-PORT, N-CEN, and prospectus Risk/Return summaries). FundWatcher is not affiliated with the SEC.",
  "terms": {
    "notice": "Use of this data is subject to the FundWatcher Terms of Service. Information may be used only for personal, non-commercial research and may not be redistributed.",
    "url": "https://fundwatcher.app/terms/"
  },
  "fund_a": {
    "name": "MFS Massachusetts Municipal Bond Fund",
    "ticker": "MBMAX",
    "slug": "MBMAX",
    "series_id": "S000002534",
    "html_url": "https://fundwatcher.app/funds/MBMAX/"
  },
  "fund_b": {
    "name": "MFS Maryland Municipal Bond Fund",
    "ticker": "MFSMX",
    "slug": "MFSMX",
    "series_id": "S000002533",
    "html_url": "https://fundwatcher.app/funds/MFSMX/"
  },
  "overlap": {
    "coverage_a_by_b": "0.09386735669204304929064749133",
    "coverage_b_by_a": "0.09386735669204304929064749133",
    "shared_count": 54,
    "as_of": {
      "a": "2026-03-31",
      "b": "2026-03-31"
    },
    "a_top": [
      {
        "name": "MFS Institutional Money Market Portfolio, Class A",
        "value": "6780076.38",
        "weight": "0.01677377",
        "shared": true
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY R REGD B/E 5.00000000",
        "value": "5519077.50",
        "weight": "0.01365409",
        "shared": false
      },
      {
        "name": "Commonwealth of Massachusetts Transportation Fund, Series 2025A",
        "value": "5246705.50",
        "weight": "0.01298024",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "5015128.50",
        "weight": "0.01240733",
        "shared": false
      },
      {
        "name": "MA CLEAN WTR TRUST-27",
        "value": "4238510.00",
        "weight": "0.01048599",
        "shared": false
      },
      {
        "name": "MBTA SLS TAX 5.25% 7/1/55",
        "value": "4197145.60",
        "weight": "0.01038365",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST",
        "value": "4174933.60",
        "weight": "0.01032870",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST SCH BLDG AUTH SALES TAX REVENUE",
        "value": "4156830.40",
        "weight": "0.01028392",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST SCH BLDG AUTH SALES TAX REVENUE",
        "value": "4139378.40",
        "weight": "0.01024074",
        "shared": false
      },
      {
        "name": "MA ST TRANS REV 5% 6/1/2053",
        "value": "4128929.20",
        "weight": "0.01021489",
        "shared": false
      },
      {
        "name": "Tri-County Regional Vocational Technical School District, Series CHAPTER 70B",
        "value": "3897596.00",
        "weight": "0.00964257",
        "shared": false
      },
      {
        "name": "MASS DEVEL FIN 4% 10/1/2045",
        "value": "3683306.52",
        "weight": "0.00911243",
        "shared": false
      },
      {
        "name": "PUERTO RICO SALES TAX FING COR REGD OID B/E 5.00000000",
        "value": "3618162.86",
        "weight": "0.00895126",
        "shared": true
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "3613758.75",
        "weight": "0.00894037",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST PORT AUTH",
        "value": "3600171.84",
        "weight": "0.00890675",
        "shared": false
      },
      {
        "name": "Massachusetts Development Finance Agency, Series 2025W",
        "value": "3580581.24",
        "weight": "0.00885829",
        "shared": false
      },
      {
        "name": "Town of Tisbury",
        "value": "3576179.50",
        "weight": "0.00884740",
        "shared": false
      },
      {
        "name": "Massachusetts Housing Finance Agency",
        "value": "3515743.88",
        "weight": "0.00869788",
        "shared": false
      },
      {
        "name": "Massachusetts Bay Transportation Authority, Series 2025 B",
        "value": "3220527.00",
        "weight": "0.00796752",
        "shared": false
      },
      {
        "name": "Massachusetts Educational Financing Authority",
        "value": "3190051.60",
        "weight": "0.00789212",
        "shared": false
      },
      {
        "name": "WAKEFIELD MA REGD B/E 5.00000000",
        "value": "3159303.90",
        "weight": "0.00781605",
        "shared": false
      },
      {
        "name": "Massachusetts Development Finance Agency",
        "value": "3136652.54",
        "weight": "0.00776002",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "3128461.80",
        "weight": "0.00773975",
        "shared": false
      },
      {
        "name": "MA ST TRANS REV 5% 6/1/2049",
        "value": "3112573.20",
        "weight": "0.00770044",
        "shared": false
      },
      {
        "name": "MASS DEVEL FIN 5% 7/1/2048",
        "value": "3106466.46",
        "weight": "0.00768534",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST PORT AUTH REGD B/E AMT 5.00000000",
        "value": "3065727.02",
        "weight": "0.00758455",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST",
        "value": "3061399.50",
        "weight": "0.00757384",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST PORT AUTH",
        "value": "3053706.60",
        "weight": "0.00755481",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST TRANSPRTN FUND REVENUE",
        "value": "3051318.00",
        "weight": "0.00754890",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY R REGD B/E 5.50000000",
        "value": "3048717.60",
        "weight": "0.00754247",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY R REGD B/E 5.00000000",
        "value": "3037816.50",
        "weight": "0.00751550",
        "shared": false
      },
      {
        "name": "Massachusetts Housing Finance Agency",
        "value": "3031967.70",
        "weight": "0.00750103",
        "shared": false
      },
      {
        "name": "Massachusetts Port Authority, Revenue Bonds, Refunding Series 2017A",
        "value": "3019395.90",
        "weight": "0.00746992",
        "shared": false
      },
      {
        "name": "Massachusetts (Commonwealth of), Series 2024 E, GO Bonds",
        "value": "3013826.13",
        "weight": "0.00745615",
        "shared": false
      },
      {
        "name": "Massachusetts Housing Finance Agency, Series 2013B",
        "value": "3000481.50",
        "weight": "0.00742313",
        "shared": false
      },
      {
        "name": "Massachusetts Housing Finance Agency, Series 249",
        "value": "2982815.10",
        "weight": "0.00737942",
        "shared": false
      },
      {
        "name": "S E ENERGY COOP DT",
        "value": "2925100.78",
        "weight": "0.00723664",
        "shared": false
      },
      {
        "name": "MA ST DEV FIN -J2",
        "value": "2888537.40",
        "weight": "0.00714618",
        "shared": false
      },
      {
        "name": "Nashoba Regional School District",
        "value": "2882022.33",
        "weight": "0.00713007",
        "shared": false
      },
      {
        "name": "Commonwealth of Massachusetts Transportation Fund Revenue",
        "value": "2859262.50",
        "weight": "0.00707376",
        "shared": false
      },
      {
        "name": "Massachusetts Development Finance Agency 4.00% 07/01/2039",
        "value": "2848928.03",
        "weight": "0.00704819",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST PORT AUTH",
        "value": "2832906.44",
        "weight": "0.00700855",
        "shared": false
      },
      {
        "name": "Town of Hingham, Series 2025",
        "value": "2813363.75",
        "weight": "0.00696021",
        "shared": false
      },
      {
        "name": "NEW BEDFORD MA",
        "value": "2771977.80",
        "weight": "0.00685782",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "2770168.63",
        "weight": "0.00685334",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "2721192.71",
        "weight": "0.00673218",
        "shared": false
      },
      {
        "name": "MA ST DEV FIN AGY-N",
        "value": "2709922.68",
        "weight": "0.00670429",
        "shared": false
      },
      {
        "name": "Massachusetts Housing Finance Agency, Single Family Housing Revenue Bonds, Social Series 2024-234",
        "value": "2705206.90",
        "weight": "0.00669263",
        "shared": false
      },
      {
        "name": "Massachusetts Development Finance Agency",
        "value": "2624785.64",
        "weight": "0.00649367",
        "shared": false
      },
      {
        "name": "CALIFORNIA ST HLTH FACS FING AUTH REVENUE",
        "value": "2485529.50",
        "weight": "0.00614915",
        "shared": false
      }
    ],
    "b_top": [
      {
        "name": "MFS Institutional Money Market Portfolio, Class A",
        "value": "5117103.28",
        "weight": "0.03287827",
        "shared": true
      },
      {
        "name": "MARYLAND ST ECON DEV CORP LEASE REVENUE",
        "value": "2066416.60",
        "weight": "0.01327708",
        "shared": false
      },
      {
        "name": "Maryland Economic Development Corp., Series 2024",
        "value": "1956308.20",
        "weight": "0.01256962",
        "shared": false
      },
      {
        "name": "Montgomery (County of), MD, Series 2017, GO Bonds",
        "value": "1900000.00",
        "weight": "0.01220783",
        "shared": false
      },
      {
        "name": "MARYLAND ST STD 5% 5/1/2035",
        "value": "1785164.72",
        "weight": "0.01146999",
        "shared": false
      },
      {
        "name": "PUERTO RICO SALES TAX FING COR REGD OID B/E 5.00000000",
        "value": "1727325.78",
        "weight": "0.01109837",
        "shared": true
      },
      {
        "name": "County of Prince George's, Series 2025 A",
        "value": "1607726.55",
        "weight": "0.01032992",
        "shared": false
      },
      {
        "name": "Washington Metropolitan Area Transit Authority Dedicated",
        "value": "1607187.60",
        "weight": "0.01032646",
        "shared": false
      },
      {
        "name": "Maryland Stadium Authority, Series 2024",
        "value": "1571792.40",
        "weight": "0.01009904",
        "shared": false
      },
      {
        "name": "County of Anne Arundel, Series 2025",
        "value": "1562597.40",
        "weight": "0.01003996",
        "shared": false
      },
      {
        "name": "MD HLTH & HGR EDL-A",
        "value": "1561890.15",
        "weight": "0.01003541",
        "shared": false
      },
      {
        "name": "Maryland Health & Higher Educational Facilities Authority",
        "value": "1554150.45",
        "weight": "0.00998568",
        "shared": false
      },
      {
        "name": "PRINCE GEO COP 5% 10/1/48",
        "value": "1524666.75",
        "weight": "0.00979625",
        "shared": false
      },
      {
        "name": "Maryland Community Development Administration, Series 2025 F-1",
        "value": "1506350.25",
        "weight": "0.00967856",
        "shared": false
      },
      {
        "name": "MARYLAND STADIUM AUTHORITY",
        "value": "1492435.35",
        "weight": "0.00958915",
        "shared": false
      },
      {
        "name": "WASHINGTON SUBURBAN SANITARY COMMISSION",
        "value": "1461898.35",
        "weight": "0.00939295",
        "shared": false
      },
      {
        "name": "COUNTY OF BALTIMORE MD",
        "value": "1457850.60",
        "weight": "0.00936694",
        "shared": false
      },
      {
        "name": "County of Howard",
        "value": "1424096.70",
        "weight": "0.00915007",
        "shared": false
      },
      {
        "name": "MARYLAND ST HLTH & HGR EDUCTNL FACS AUTH REVENUE",
        "value": "1406792.17",
        "weight": "0.00903888",
        "shared": false
      },
      {
        "name": "Maryland Health & Higher Educational Facilities Authority, Series 2004",
        "value": "1396223.21",
        "weight": "0.00897098",
        "shared": false
      },
      {
        "name": "County of Anne Arundel, Series 2023",
        "value": "1393211.60",
        "weight": "0.00895163",
        "shared": false
      },
      {
        "name": "City of Baltimore, Series 2019 A",
        "value": "1392087.02",
        "weight": "0.00894440",
        "shared": false
      },
      {
        "name": "Maryland Community Development Administration Department of Housing and Community Development, Residential Revenue Bonds, Taxable Series 2019D",
        "value": "1391971.66",
        "weight": "0.00894366",
        "shared": false
      },
      {
        "name": "MARYLAND ST STA 4% 6/1/2046",
        "value": "1314577.29",
        "weight": "0.00844639",
        "shared": false
      },
      {
        "name": "MARYLAND HEALTH & HIGHER EDUCATIONAL FACILITIES AUTHORITY",
        "value": "1288038.33",
        "weight": "0.00827587",
        "shared": false
      },
      {
        "name": "Maryland Health & Higher Educational Facilities Authority",
        "value": "1260651.72",
        "weight": "0.00809990",
        "shared": false
      },
      {
        "name": "MONTGOMERY CNTY MD REVENUE REGD B/E 5.00000000",
        "value": "1240317.19",
        "weight": "0.00796925",
        "shared": false
      },
      {
        "name": "Maryland Community Development Administration Local Government Infrastructure",
        "value": "1230218.13",
        "weight": "0.00790436",
        "shared": false
      },
      {
        "name": "MD CMNTY DEV-D-1",
        "value": "1190841.13",
        "weight": "0.00765136",
        "shared": false
      },
      {
        "name": "Washington Metropolitan Area Transit Authority, Series 2018, RB",
        "value": "1155596.68",
        "weight": "0.00742491",
        "shared": false
      },
      {
        "name": "MD HEFA 4% 7/1/2048",
        "value": "1108365.50",
        "weight": "0.00712144",
        "shared": false
      },
      {
        "name": "County of Montgomery",
        "value": "1107250.70",
        "weight": "0.00711428",
        "shared": false
      },
      {
        "name": "MD CMNTY DEPT ADMIN-B",
        "value": "1097910.15",
        "weight": "0.00705426",
        "shared": false
      },
      {
        "name": "Maryland Health & Higher Educational Facilities Authority",
        "value": "1094371.76",
        "weight": "0.00703153",
        "shared": false
      },
      {
        "name": "CALIFORNIA COMMUNITY VAR",
        "value": "1081998.20",
        "weight": "0.00695203",
        "shared": false
      },
      {
        "name": "MD TRANSPRTN-A-REF",
        "value": "1080306.40",
        "weight": "0.00694116",
        "shared": false
      },
      {
        "name": "Montgomery County Housing Opportunities Commission, Series 2023 C",
        "value": "1076666.80",
        "weight": "0.00691777",
        "shared": false
      },
      {
        "name": "Maryland Department of Housing & Community Development, Series 2024 E",
        "value": "1076506.43",
        "weight": "0.00691674",
        "shared": false
      },
      {
        "name": "MD ECON DEV CORP-A",
        "value": "1072393.30",
        "weight": "0.00689031",
        "shared": false
      },
      {
        "name": "County of Prince George's",
        "value": "1040425.00",
        "weight": "0.00668491",
        "shared": false
      },
      {
        "name": "MARYLAND ST ECON DEV CORP AIR CARGO REVENUE",
        "value": "1040054.84",
        "weight": "0.00668253",
        "shared": false
      },
      {
        "name": "Washington Metropolitan Area Transit Authority, Series 2025, RB",
        "value": "1038645.70",
        "weight": "0.00667348",
        "shared": false
      },
      {
        "name": "Maryland Stadium Authority Sports Entertainment Facilities Revenue, Series 2023 A",
        "value": "1034419.30",
        "weight": "0.00664632",
        "shared": false
      },
      {
        "name": "State of Maryland Department of Transportation, Series 2024 A",
        "value": "1032954.50",
        "weight": "0.00663691",
        "shared": false
      },
      {
        "name": "MARYLAND ST HLTH & HGR EDUCTNL MARYLAND HEALTH & HIGHER EDUCATIONAL FACILITIES AU",
        "value": "1031303.10",
        "weight": "0.00662630",
        "shared": false
      },
      {
        "name": "MARYLAND ST HLTH & HGR EDUCTNL FACS AUTH REVENUE",
        "value": "1025953.80",
        "weight": "0.00659193",
        "shared": false
      },
      {
        "name": "Maryland Department of Housing & Community Development, Series 2025 D",
        "value": "1024100.00",
        "weight": "0.00658002",
        "shared": false
      },
      {
        "name": "State of Maryland Department of Transportation, Series 2024 A",
        "value": "1023701.30",
        "weight": "0.00657746",
        "shared": false
      },
      {
        "name": "MARYLAND ST STA 4% 6/1/2036",
        "value": "1022381.10",
        "weight": "0.00656898",
        "shared": false
      },
      {
        "name": "Montgomery County Housing Opportunities Commission, Series 2025A",
        "value": "1021211.30",
        "weight": "0.00656146",
        "shared": false
      }
    ]
  },
  "error": null,
  "sources": [
    {
      "label": "N-PORT (fund A)",
      "accession_no": "0002071691-26-011422",
      "as_of": "2026-03-31",
      "edgar_url": "https://www.sec.gov/Archives/edgar/data/751656/000207169126011422/0002071691-26-011422-index.htm"
    },
    {
      "label": "N-PORT (fund B)",
      "accession_no": "0002071691-26-011429",
      "as_of": "2026-03-31",
      "edgar_url": "https://www.sec.gov/Archives/edgar/data/751656/000207169126011429/0002071691-26-011429-index.htm"
    }
  ]
}