Which counties are gaining MA share fastest?
Data through Plan year 2026, with 2023–2026 penetration history · Updated May 1, 2026
static extract
Miami-Dade, FL is gaining MA share fastest among tracked counties: +1.35 points year-over-year to 74.2%. 9 of the 10 fastest counties are in Florida, meaning current MA momentum is a switcher battle inside saturated metros rather than new-market conversion.
74.2%
Highest county penetration (Miami-Dade, FL)
Plan year 2026, with 2023–2026 penetration history
9/10
Top-10 momentum counties in Florida
Plan year 2026, with 2023–2026 penetration history
Top 12 tracked counties by YoY penetration gain
Velocity = 2026 penetration minus 2025, in percentage points. “→ n%” shows the resulting 2026 penetration. 76 high-signal counties tracked; full universe coming with the CPSC pipeline.
Data table — top 20 counties with 4-year penetration history
| County | St | 2023 | 2024 | 2025 | 2026 | YoY pts | D-SNP % | Top carrier |
|---|---|---|---|---|---|---|---|---|
| Miami-Dade | FL | 70.1% | 71.8% | 73% | 74.2% | +1.35 | 31% | UHC |
| Broward | FL | 68.2% | 69.4% | 70.8% | 71.8% | +1.2 | 24% | Humana |
| Orange | FL | 61.2% | 62.4% | 63.8% | 64.8% | +1.2 | 20% | Centene |
| Lake | FL | 64.2% | 65.4% | 66.8% | 67.8% | +1.2 | 15% | Humana |
| Palm Beach | FL | 66.8% | 68.2% | 69.4% | 70.1% | +1.1 | 19% | BCBS |
| Hillsborough | FL | 63.1% | 64.2% | 65.4% | 66.4% | +1.1 | 22% | UHC |
| Duval | FL | 59.1% | 60.4% | 61.4% | 62.3% | +1.07 | 18% | UHC |
| Brevard | FL | 65.2% | 66.4% | 67.4% | 68.4% | +1.07 | 16% | Humana |
| Citrus | FL | 69% | 70.2% | 71.2% | 72.1% | +1.03 | 17% | Centene |
| Los Angeles | CA | 62.1% | 63.2% | 64.1% | 64.9% | +0.93 | 17% | Kaiser |
| El Paso | TX | 60% | 61% | 62% | 62.8% | +0.93 | 28% | Centene |
| Bexar | TX | 56.4% | 57.4% | 58.2% | 59.1% | +0.9 | 21% | UHC |
| Philadelphia | PA | 59.4% | 60.4% | 61.2% | 62.1% | +0.9 | 32% | Centene |
| Lucas | OH | 55.4% | 56.4% | 57.2% | 58.1% | +0.9 | 26% | Centene |
| San Bernardino | CA | 59.2% | 60.1% | 61% | 61.8% | +0.87 | 18% | Centene |
| Harris | TX | 55.2% | 56.2% | 57% | 57.8% | +0.87 | 18% | UHC |
| Dallas | TX | 52.8% | 53.8% | 54.6% | 55.4% | +0.87 | 16% | Centene |
| Tarrant | TX | 50.6% | 51.6% | 52.4% | 53.2% | +0.87 | 15% | UHC |
| Travis | TX | 45.8% | 46.8% | 47.6% | 48.4% | +0.87 | 12% | Aetna |
| Lubbock | TX | 54.2% | 55.2% | 56% | 56.8% | +0.87 | 20% | UHC |
So what / Now what
Momentum is concentrated in already-high-penetration Florida metros — growth there is switcher-driven and D-SNP-heavy, not conversion. Counties combining above-average velocity with sub-60% penetration are the genuine expansion plays.
- Market entry: filter the CSV for velocity ≥ 1.0pt and penetration < 60% to get the short list of true conversion markets.
- Competitive defense: in top-velocity counties, check which carrier is capturing the growth (top-carrier column) before committing AEP budget.
- Watch D-SNP share — several fast counties grow primarily through dual-eligible products; see the dual-eligible density page.
Provenance — County-level MA market snapshot (76 tracked counties)
- Source file
- CMS MA Enrollment by State/County/Plan (CPSC monthly files)
- Vintage
- Plan year 2026, with 2023–2026 penetration history
- Last updated
- May 1, 2026
- Refresh cadence
- Monthly (pipeline pending; currently a curated extract)
- Method
- Penetration, D-SNP share, carrier count and top carrier per county compiled from CPSC files for 76 high-signal counties.
- Known limitations
- Covers 76 tracked counties, not all ~3,100. Velocity = simple YoY penetration point change.