{
  "page": "compare",
  "query": {
    "a": "AMACX",
    "b": "MFSSX"
  },
  "retrieved_at": "2026-07-07T19:12:19+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": "AB Massachusetts Portfolio",
    "ticker": "AMACX",
    "slug": "AMACX",
    "series_id": "S000010355",
    "html_url": "https://fundwatcher.app/funds/AMACX/"
  },
  "fund_b": {
    "name": "MFS Massachusetts Municipal Bond Fund",
    "ticker": "MFSSX",
    "slug": "MFSSX",
    "series_id": "S000002534",
    "html_url": "https://fundwatcher.app/funds/MFSSX/"
  },
  "overlap": {
    "coverage_a_by_b": "0.07446347165107061990286048286",
    "coverage_b_by_a": "0.07446347165107061990286048286",
    "shared_count": 19,
    "as_of": {
      "a": "2026-02-28",
      "b": "2026-03-31"
    },
    "a_top": [
      {
        "name": "QUINCY MA",
        "value": "7329477.65",
        "weight": "0.02826054",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "7154974.97",
        "weight": "0.02758770",
        "shared": true
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "5607897.34",
        "weight": "0.02162258",
        "shared": false
      },
      {
        "name": "Massachusetts Water Resources Authority",
        "value": "5567857.90",
        "weight": "0.02146820",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST MAS 12/54 FIXED 5",
        "value": "5246557.00",
        "weight": "0.02022934",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST",
        "value": "5173718.50",
        "weight": "0.01994850",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST PORT AUTH REGD B/E AMT 5.00000000",
        "value": "5066577.50",
        "weight": "0.01953539",
        "shared": true
      },
      {
        "name": "MASSACHUSETTS ST PORT AUTH",
        "value": "5020833.45",
        "weight": "0.01935901",
        "shared": false
      },
      {
        "name": "MA ST DEV FIN AGY",
        "value": "4318442.40",
        "weight": "0.01665078",
        "shared": false
      },
      {
        "name": "MBTA SLS TAX 5.25% 7/1/2053",
        "value": "4251004.40",
        "weight": "0.01639076",
        "shared": false
      },
      {
        "name": "MA ST",
        "value": "4248466.80",
        "weight": "0.01638097",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST PORT AUTH",
        "value": "4237713.60",
        "weight": "0.01633951",
        "shared": false
      },
      {
        "name": "MBTA SLS TAX 5.25% 7/1/55",
        "value": "3758543.25",
        "weight": "0.01449195",
        "shared": true
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY R REGD B/E 5.00000000",
        "value": "3756941.71",
        "weight": "0.01448578",
        "shared": false
      },
      {
        "name": "MASS DEVEL FIN 5% 7/1/2050",
        "value": "3558042.53",
        "weight": "0.01371888",
        "shared": false
      },
      {
        "name": "QUINCY MA",
        "value": "3502745.59",
        "weight": "0.01350567",
        "shared": false
      },
      {
        "name": "PRG MEDFORD PROPERTIES INC 5.25% 06-01-55",
        "value": "3401821.15",
        "weight": "0.01311653",
        "shared": true
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "3323480.65",
        "weight": "0.01281447",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "3300276.60",
        "weight": "0.01272500",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "3149945.60",
        "weight": "0.01214536",
        "shared": true
      },
      {
        "name": "MASS CMNWLTH-B",
        "value": "3138277.50",
        "weight": "0.01210037",
        "shared": false
      },
      {
        "name": "MA ST TRANS REV 5% 6/1/52",
        "value": "3115159.20",
        "weight": "0.01201123",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST BAY TRANSPRTN MASTRN 07/50 FIXED 5",
        "value": "3053340.30",
        "weight": "0.01177288",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "3053237.40",
        "weight": "0.01177248",
        "shared": false
      },
      {
        "name": "MASS DEVEL FIN 5% 7/1/2053",
        "value": "3020805.90",
        "weight": "0.01164743",
        "shared": false
      },
      {
        "name": "U.S. Treasury Bills",
        "value": "2986427.64",
        "weight": "0.01151488",
        "shared": false
      },
      {
        "name": "SUFFOLK UNIVERSITY 5.25% 07-01-55",
        "value": "2985330.30",
        "weight": "0.01151065",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST PORT AUTH",
        "value": "2630395.00",
        "weight": "0.01014211",
        "shared": true
      },
      {
        "name": "UNIV OF MASSACHUSETTS MA BLDG AUTH REVENUE",
        "value": "2600748.00",
        "weight": "0.01002780",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "2502547.25",
        "weight": "0.00964916",
        "shared": true
      },
      {
        "name": "MASSACHUSETTS ST",
        "value": "2453085.63",
        "weight": "0.00945845",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "2325443.54",
        "weight": "0.00896630",
        "shared": false
      },
      {
        "name": "MA ST DEV FIN AGY-M",
        "value": "2315681.40",
        "weight": "0.00892866",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "2267176.50",
        "weight": "0.00874164",
        "shared": true
      },
      {
        "name": "Territory of Guam, Series F",
        "value": "2242394.55",
        "weight": "0.00864608",
        "shared": true
      },
      {
        "name": "MASSACHUSETTS ST",
        "value": "2181310.00",
        "weight": "0.00841056",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY R MASDEV 07/54 FIXED OID 5",
        "value": "2160222.24",
        "weight": "0.00832925",
        "shared": true
      },
      {
        "name": "MASSACHUSETTS ST",
        "value": "2155022.40",
        "weight": "0.00830920",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST PORT AUTH SPL FACS REVENUE",
        "value": "2136257.40",
        "weight": "0.00823685",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "2122107.40",
        "weight": "0.00818229",
        "shared": true
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "2108237.46",
        "weight": "0.00812881",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST MAS 10/52 FIXED 5",
        "value": "2085703.26",
        "weight": "0.00804192",
        "shared": false
      },
      {
        "name": "WORCESTER MA",
        "value": "2075932.04",
        "weight": "0.00800425",
        "shared": false
      },
      {
        "name": "MA ST TRANS REV 5% 6/1/50",
        "value": "2075602.60",
        "weight": "0.00800298",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY REVENUE",
        "value": "2069881.84",
        "weight": "0.00798092",
        "shared": false
      },
      {
        "name": "MA ST DFA 5% 7/1/39",
        "value": "2058526.17",
        "weight": "0.00793714",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST BAY TRANSPRTN AUTH SALES TAX REVENUE",
        "value": "2056412.80",
        "weight": "0.00792899",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST HLTH & EDUCTNL FACS AUTH REVENUE",
        "value": "2054407.68",
        "weight": "0.00792126",
        "shared": false
      },
      {
        "name": "QUINCY MA",
        "value": "2030217.40",
        "weight": "0.00782798",
        "shared": false
      },
      {
        "name": "MASSACHUSETTS ST DEV FIN AGY R REGD B/E 5.00000000",
        "value": "2011219.80",
        "weight": "0.00775473",
        "shared": false
      }
    ],
    "b_top": [
      {
        "name": "MFS Institutional Money Market Portfolio, Class A",
        "value": "6780076.38",
        "weight": "0.01677377",
        "shared": false
      },
      {
        "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": true
      },
      {
        "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": true
      },
      {
        "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": true
      },
      {
        "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
      }
    ]
  },
  "error": null,
  "sources": [
    {
      "label": "N-PORT (fund A)",
      "accession_no": "0001410368-26-040406",
      "as_of": "2026-02-28",
      "edgar_url": "https://www.sec.gov/Archives/edgar/data/899774/000141036826040406/0001410368-26-040406-index.htm"
    },
    {
      "label": "N-PORT (fund B)",
      "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"
    }
  ]
}