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 | Updated |
|---|---|---|---|---|
| ↓ ma_state_enrollment.csv | MA enrollment & penetration by state | CMS Medicare Monthly Enrollment (data.cms.gov, public API) | February 2026 | June 15, 2026 |
| ↓ ma_county_markets.csv | County-level MA market snapshot (76 tracked counties) | CMS MA Enrollment by State/County/Plan (CPSC monthly files) | Plan year 2026, with 2023–2026 penetration history | May 1, 2026 |
| ↓ ma_national_history.csv | National MA vs Original Medicare, 2010–2026 | CMS Medicare Monthly Enrollment; CMS MA landscape files (historical) | Plan year 2026 (Feb 2026 enrollment) | June 15, 2026 |
| ↓ dual_eligible_density.csv | Dual-eligible density by state | CMS Medicare-Medicaid dual enrollment data (MMCO quarterly) | 2025 Q4 | March 15, 2026 |
| ↓ snp_state_share.csv | SNP share of MA enrollment by state | CMS SNP Comprehensive Report (monthly) | February 2026 | May 1, 2026 |
| ↓ sales_aep_target_states.csv | 2026 plan exits and member migration | CMS 2026 non-renewal notices; carrier investor disclosures | Plan year 2026 (announced fall 2025) | January 20, 2026 |
| ↓ sales_growth_runway.csv | Growth runway index by state and county | MedicareInsights index computed from CMS Medicare Monthly Enrollment and CPSC county extracts | Plan year 2026 (Feb 2026 enrollment) | July 17, 2026 |
| ↓ sales_whitespace_counties.csv | County-level MA market snapshot (76 tracked counties) | CMS MA Enrollment by State/County/Plan (CPSC monthly files) | Plan year 2026, with 2023–2026 penetration history | May 1, 2026 |
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 enrollment & penetration by state
County-level MA market snapshot (76 tracked 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
County-level MA market snapshot (76 tracked counties)
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