{
 "id": "cms:ae8c9418-acc9-4442-b217-33291448f6b8",
 "slug": "number-of-accountable-care-organization-assigned-beneficiaries-by-county",
 "source": "data.cms.gov",
 "title": "Number of Accountable Care Organization Assigned Beneficiaries by County",
 "summary": "The Shared Savings Program Number of Accountable Care Organization Assigned Beneficiaries by County dataset provides aggregate data of total assigned beneficiaries by Shared Savings Program ACO for each county where at...",
 "description": "The Shared Savings Program Number of Accountable Care Organization Assigned Beneficiaries by County dataset provides aggregate data of total assigned beneficiaries by Shared Savings Program ACO for each county where at least one of their assigned beneficiaries resides. Assigned beneficiary person-year counts are based on certified Shared Savings Program ACO Participant Lists and assignment methodology for that performance year.",
 "aliases": [],
 "keywords": [
  "Medicare",
  "Original Medicare",
  "Value-Based Care",
  "Coordinated Care",
  "Payment Models",
  "Accountable Care Organizations"
 ],
 "themes": [
  "Medicare"
 ],
 "topics": [
  "aco-value-based",
  "spending-utilization",
  "quality"
 ],
 "category": "medicare-shared-savings-program",
 "publisher": "Office of Enterprise Data and Analytics (OEDA)",
 "contact": "SharedSavingsProgram@cms.hhs.gov",
 "landing_url": "https://data.cms.gov/medicare-shared-savings-program/number-of-accountable-care-organization-assigned-beneficiaries-by-county",
 "csv_url": "https://data.cms.gov/sites/default/files/2025-11/c9b8923e-5bb4-4d28-8387-48d9bde5e74c/Number_Of_ACO_Assigned_Beneficiaries_by_County_PUF_2024_01_01.csv",
 "api_url": "https://data.cms.gov/data-api/v1/dataset/ae8c9418-acc9-4442-b217-33291448f6b8/data",
 "api_kind": "cms-data-api",
 "preview_url": "https://data.cms.gov/data-api/v1/dataset/ae8c9418-acc9-4442-b217-33291448f6b8/data?size=10",
 "dictionary_url": "https://data.cms.gov/resources/number-of-accountable-care-organization-assigned-beneficiaries-by-county-data-dictionary-2023",
 "dictionary_kind": "page",
 "methodology_urls": [
  "https://data.cms.gov/resources/number-of-accountable-care-organization-assigned-beneficiaries-by-county-methodology"
 ],
 "state_column": "State_Name",
 "row_count": 135203,
 "posted": "2025-11-17",
 "modified": "2025-11-17",
 "period_start": "2016-01-01",
 "period_end": "2024-12-31",
 "latest_period": "2024-01-01 to 2024-12-31",
 "cadence": "annually",
 "next_update": null,
 "versions": [
  {
   "label": "2024-12-01",
   "uuid": "ae8c9418-acc9-4442-b217-33291448f6b8",
   "posted": "2025-11-17",
   "period_start": "2024-01-01",
   "period_end": "2024-12-31"
  },
  {
   "label": "2023-01-01",
   "uuid": "4f64f8d2-f62b-4690-8ce4-85a9cf9adb76",
   "posted": "2025-11-05",
   "period_start": "2023-01-01",
   "period_end": "2023-12-31"
  },
  {
   "label": "2022-02-01",
   "uuid": "7071eb0c-71b6-450d-b3c2-077a3166ed46",
   "posted": "2024-01-23",
   "period_start": "2022-01-01",
   "period_end": "2022-12-31"
  },
  {
   "label": "2021-01-31",
   "uuid": "95490093-9f62-4566-b9bf-693d2a00fe08",
   "posted": "2022-09-20",
   "period_start": "2021-01-01",
   "period_end": "2021-12-31"
  },
  {
   "label": "2020-01-01",
   "uuid": "cff04cbb-6267-47ec-b69d-7a2315b36df3",
   "posted": "2022-09-12",
   "period_start": "2020-01-01",
   "period_end": "2020-12-31"
  },
  {
   "label": "2019-07-01oc1",
   "uuid": "d73a38fb-2e6e-469f-b369-f685fd45f424",
   "posted": "2024-01-23",
   "period_start": "2019-01-01",
   "period_end": "2019-12-31"
  },
  {
   "label": "2019-01-31",
   "uuid": "d076f7f0-536a-4944-aa56-8930ced2a06d",
   "posted": "2021-11-30",
   "period_start": "2019-01-01",
   "period_end": "2019-12-31"
  },
  {
   "label": "2018-01-15",
   "uuid": "ee439bd7-ac96-43aa-99c7-86e5c8ede0bc",
   "posted": "2021-11-30",
   "period_start": "2018-01-01",
   "period_end": "2018-12-31"
  },
  {
   "label": "2017-01-15",
   "uuid": "c2b153f1-8354-4132-b6ac-9817023db82f",
   "posted": "2021-11-30",
   "period_start": "2017-01-01",
   "period_end": "2017-12-31"
  },
  {
   "label": "2016-01-15",
   "uuid": "ff0d442b-8c0d-44ba-b8cd-6e392e30fab0",
   "posted": "2021-11-30",
   "period_start": "2016-01-01",
   "period_end": "2016-12-31"
  }
 ],
 "columns": [
  {
   "name": "Year",
   "label": "Year",
   "type": "number",
   "meaning": "Calendar year (CY) for which assigned beneficiaries are determined.",
   "source": "cms-dictionary"
  },
  {
   "name": "ACO_ID",
   "label": "ACO ID",
   "type": "string",
   "meaning": "Unencrypted ACO identifier. This identifier can be linked to the encrypted ACO identifier used for prior performance years (Refer to Notes).",
   "source": "cms-dictionary"
  },
  {
   "name": "State_Name",
   "label": "State name",
   "type": "string",
   "meaning": "State name",
   "source": "cms-dictionary"
  },
  {
   "name": "County_Name",
   "label": "County name",
   "type": "string",
   "meaning": "County name",
   "source": "cms-dictionary"
  },
  {
   "name": "State_ID",
   "label": "State ID",
   "type": "string",
   "meaning": "Social Security Administration (SSA) state code. This code should always include two numeric characters, though leading zeros may be dropped when opening the files in some programs (e.g. a value of “01” may appear as “1”).",
   "source": "cms-dictionary"
  },
  {
   "name": "County_ID",
   "label": "County ID",
   "type": "string",
   "meaning": "SSA county code. This code should always include three numeric characters, though leading zeros may be dropped when opening the files in some programs (e.g. a value of “001” may appear as “1”).",
   "source": "cms-dictionary"
  },
  {
   "name": "AB_Psn_Yrs_ESRD",
   "label": "ESRD assigned beneficiary person years",
   "type": "number",
   "meaning": "Number of assigned beneficiaries with End-Stage Renal Disease (ESRD) enrollment type in the county in the report period, adjusted for the total number of months that each beneficiary was classified as ESRD.",
   "source": "cms-dictionary"
  },
  {
   "name": "AB_Psn_Yrs_DIS",
   "label": "DISABLED assigned beneficiary person years",
   "type": "number",
   "meaning": "Number of assigned beneficiaries with DISABLED enrollment type in the county in the report period, adjusted for the total number of months that each beneficiary was classified as DISABLED.",
   "source": "cms-dictionary"
  },
  {
   "name": "AB_Psn_Yrs_AGDU",
   "label": "AGED/DUAL assigned beneficiary person years",
   "type": "number",
   "meaning": "Number of assigned beneficiaries with AGED/DUAL enrollment type in the county in the report period, adjusted for the total number of months that each beneficiary was classified as AGED/DUAL.",
   "source": "cms-dictionary"
  },
  {
   "name": "AB_Psn_Yrs_AGND",
   "label": "AGED/NON-DUAL assigned beneficiary person years",
   "type": "number",
   "meaning": "Number of assigned beneficiaries with AGED/NON-DUAL enrollment type in the county in the report period, adjusted for the total number of months that each beneficiary was classified as AGED/NON-DUAL.",
   "source": "cms-dictionary"
  },
  {
   "name": "Tot_AB_Psn_Yrs",
   "label": "Total assigned beneficiary person years",
   "type": "number",
   "meaning": "Total number of assigned beneficiaries in the county in the report period, adjusted for the total number of months that each beneficiary was classified as one of the four enrollment types.",
   "source": "cms-dictionary"
  },
  {
   "name": "Tot_AB",
   "label": "Total assigned beneficiaries",
   "type": "number",
   "meaning": "Total number of assigned beneficiaries in the county in the report period.",
   "source": "cms-dictionary"
  }
 ],
 "caveats": [],
 "curated": false,
 "license": "https://www.usa.gov/government-works",
 "detail_key": "ae8c9418-acc9-4442-b217-33291448f6b8|2025-11-17",
 "checked": "2026-10-25",
 "source_name": "data.cms.gov"
}