Data downloads
Every CSV published on the site, with its CMS source, vintage, and last-updated date. Files regenerate from the source registry on every data refresh; prior vintages are archived so old citations stay reproducible.
Current files
| File | Contents | CMS source | Vintage | Ingested | Status |
|---|---|---|---|---|---|
| ↓ ma_county_penetration_2026-04.csv | MA & other health plan enrollment and share for all 3,199 US counties | CMS Medicare Monthly Enrollment (BENE_GEO_LVL=County) | April 2026 | 2026-07-31 | live |
| ↓ dual_eligible_by_county_2026-04.csv | Dual-eligible and full-benefit dual counts by county | CMS Medicare Monthly Enrollment (BENE_GEO_LVL=County) | April 2026 | 2026-07-31 | live |
| ↓ snp_plans_2026-08.csv | Every SNP in the country by contract, plan and enrollment | CMS SNP Comprehensive Report | August 2026 | 2026-08-24 | live |
| ↓ snp_by_state_2026-08.csv | SNP enrollment by state and SNP type | CMS SNP Comprehensive Report | August 2026 | 2026-08-24 | live |
Column definitions and known limitations are in each file's provenance panel and on methodology. License: CC BY 4.0 for our compilations; the underlying CMS data is public.
Archived vintages
Snapshots of each file as published for a given data vintage. If you cited a figure from an earlier release, the file it came from is here.
MA & other health plan enrollment and share by state superseded
County-level MA market snapshot (all 3,199 US counties)
National MA vs Original Medicare, 2010–2026
Dual-eligible density by state
SNP share of MA enrollment by state
2026 plan exits and member migration
Growth runway index by state and county withdrawn
County-level MA market snapshot (all 3,199 US counties)
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Archived and withdrawn datasets
| Archived file | Why it was withdrawn | Status |
|---|---|---|
| ↓ WITHDRAWN_dual_eligible_density.csv | Withdrawn by the 2026-08-24 data audit.… | withdrawn |
| ↓ WITHDRAWN_ma_county_markets.csv | Not reproducible from any CMS file. Audited 2026-08-24 against the April 2026 county file: denominators differed by 1.4x to 995x, penetration differed by a mean of 8.5 and up to 35… | withdrawn |
| ↓ WITHDRAWN_ma_national_history.csv | Withdrawn by the 2026-08-24 data audit.… | withdrawn |
| ↓ WITHDRAWN_ma_state_enrollment.csv | Withdrawn by the 2026-08-24 data audit.… | withdrawn |
| ↓ WITHDRAWN_sales_aep_target_states.csv | Withdrawn by the 2026-08-24 data audit.… | withdrawn |
| ↓ WITHDRAWN_sales_growth_runway.csv | Withdrawn by the 2026-08-24 data audit.… | withdrawn |
| ↓ WITHDRAWN_sales_whitespace_counties.csv | Withdrawn by the 2026-08-24 data audit.… | withdrawn |
The audit is recorded in the methodology archive.