Has Medicare Advantage passed half of Medicare — and is growth slowing?
You will see MA's national share quoted anywhere from about 51% to 58%, and all of those numbers can be correct at once. The difference is the denominator and the file.
The plan-year figure counts Medicare Advantage enrollment against all Medicare beneficiaries at a fixed point in the plan year. The monthly-file figure counts MA and other managed care against beneficiaries in that specific month, and it moves every month as people age in and switch.
Neither is spin. The rule on this site is that every chart states which basis it uses, so two figures never get compared across bases without a note. Full detail at Methodology → penetration bases.
Yes — Medicare Advantage covers 50.8% of Medicare in 2026, its first majority plan year (35.2M MA vs 34.1M Original Medicare), up from 23.5% in 2010. The YoY gain of +1.2 points continues, but is below the pandemic-era pace.
Unless noted, figures are Plan year 2026.
MA share of Medicare, 2010–2026
Pure-MA basis (excludes cost plans and other non-MA coverage). The monthly-file MA+other basis runs ~7pts higher — both are shown on this site with their basis labeled.
Data table — annual series
| Year | MA (M) | Original (M) | MA % | SNP (M) | Avg premium | Avg MOOP |
|---|---|---|---|---|---|---|
| 2010 | 11.1 | 36.2 | 23.5% | 0.8 | $34 | $4,450 |
| 2011 | 11.8 | 36.1 | 24.6% | 0.9 | $32 | $4,350 |
| 2012 | 13.1 | 36 | 26.7% | 1.1 | $32 | $4,280 |
| 2013 | 14.4 | 36.1 | 28.5% | 1.3 | $31 | $4,220 |
| 2014 | 15.9 | 36.3 | 30.5% | 1.5 | $33 | $4,380 |
| 2015 | 17.1 | 36.5 | 31.9% | 1.7 | $33 | $4,450 |
| 2016 | 18.1 | 36.9 | 32.9% | 1.9 | $32 | $4,440 |
| 2017 | 19 | 37.3 | 33.7% | 2 | $31 | $4,400 |
| 2018 | 20.4 | 37.4 | 35.3% | 2.6 | $28 | $4,310 |
| 2019 | 22.1 | 37.5 | 37.1% | 3 | $23 | $4,200 |
| 2020 | 24.1 | 37.3 | 39.3% | 3.3 | $24 | $4,250 |
| 2021 | 26 | 38.8 | 40.2% | 3.7 | $21 | $5,091 |
| 2022 | 28.9 | 37.9 | 43.3% | 4.5 | $20 | $5,151 |
| 2023 | 31.4 | 37.1 | 45.8% | 5.7 | $20 | $5,400 |
| 2024 | 33.4 | 36.2 | 48% | 6.6 | $18 | $5,688 |
| 2025 | 34.4 | 34.9 | 49.6% | 7.3 | $16 | $5,400 |
| 2026 | 35.2 | 34.1 | 50.8% | 8.2 | $15 | $5,421 |
So what / Now what Interpretation
MA crossing 50% changes the strategic frame: MA is now the default Medicare product, and CMS rate policy (V28 phase-in, benchmark changes) is calibrated to a majority program. Growth continues but the cheap conversion years are ending — enrollment gains increasingly come from other MA plans.
- Board framing: use 50.8% (2026 plan year) as the headline; cite the pure-MA basis, not the higher monthly MA+other basis.
- Forecasting: pair this trend with state health-plan share headroom — national deceleration masks wide state-level variance.
- Watch SNP mix: 8.2M SNP enrollees are the fastest-compounding slice; SNP-light portfolios are underweight the growth segment.
Provenance — National MA vs Original Medicare, 2010–2026
- Source file
- CMS Medicare Monthly Enrollment; CMS MA landscape files (historical)
- Vintage
- April 2026
- Last updated
- July 31, 2026
- Refresh cadence
- Monthly enrollment; annual landscape
- Method
- Year-end MA and Original Medicare enrollment in millions; premiums/MOOP are enrollment-weighted plan-year averages.
- Known limitations
- Static extract pending automated pipeline. Premium/MOOP averages compiled from CMS landscape releases, not recomputed here.