Medicare Advantage denial rates by insurer
In 2024, Medicare Advantage insurers made about 52.8 million prior-authorization determinations and denied roughly 4.1 million of them. Yet only about 1 in 9 denials is ever appealed — and when patients do appeal, ~81% of appealed MA prior-authorization denials are overturned.
If your Medicare Advantage plan denied a test, service, or stay, appealing is usually worth it. Across the market, ~81% of appealed ma prior-authorization denials are overturned. Denials for a skilled-nursing stay are overturned even more often — 95% of SNF denials overturned on appeal (OIG).
| Insurer | MA enrollment | Denial rate | Denials appealed | Overturned on appeal |
|---|---|---|---|---|
| UnitedHealthcare | 9.3M | 12.6% | 12.0% | 78.8% |
| Wellcare (Centene) | — | 11.9% | 7.5% | 95.3% |
| Aetna (CVS Health) | — | 11.6% | 21.4% | 92.6% |
| Kaiser Permanente | — | 10.3% | 1.7% | 50.2% |
| Humana | 7.0M | 5.5% | 11.6% | 64.7% |
| Anthem (Elevance Health) | — | 4.1% | 9.1% | 87.9% |
| All Medicare Advantage | 35.2M | 7.3% | 12.2% | 80.7% |
Insurer / contract level. Medicare does not publish per-plan denial rates. Rates are 2024 prior-authorization determinations. Click an insurer for its posted policies and detail.
Other insurers, reported a different way
The table above covers the six parent companies big enough to be named in the national comparison — every insurer with a million or more Medicare Advantage members. Smaller insurers aren’t broken out there. What they do publish is their own annual prior-authorization filing, which CMS began requiring in 2026 for calendar-year 2025. Those numbers can’t be lined up against the ones above — different year, different counting — so they’re listed separately here.
| Insurer | MA enrollment | Standard requests denied (2025) | Approved after appeal (2025) |
|---|---|---|---|
| HCSC / HealthSpring | 897,246 | 5% / 12% | 81% / 80% |
| Blue Cross Blue Shield of Michigan | 674,356 | 4.26% | 88.9% |
| Highmark | 424,629 | 3.76% | 77.6% |
Insurer / contract level. Medicare does not publish per-plan denial rates. Figures are each insurer’s own calendar-year 2025 filing under the CMS Interoperability and Prior Authorization rule (CMS-0057-F). Where two figures are shown, the parent company filed two separate reports and does not publish enough detail to combine them. “Approved after appeal” is the share of appealed denials later approved — not a share of all denials.
Why appealing usually works
A Medicare Advantage plan is legally required to cover anything Original Medicare covers. When you appeal a denial, the plan must have a clinician review it — and if they still say no, your case is automatically forwarded to an independent reviewer (you don’t file anything). You generally have 60 days from the denial notice to ask for a reconsideration, with a 72-hour expedited path when your health or a hospital/rehab discharge is at stake.
Facing a rehab or nursing-facility discharge right now?
There’s a same-day fast-track appeal with hour-level deadlines.
Skilled-nursing discharge appeal →Data as of September 2026. CMS Part C reporting + KFF analysis of 2024 determinations + each insurer's CMS-0057-F postings (CY2025) + CMS Monthly Enrollment by Contract (Sept 2026). KFF chart datasets re-verified 2026-09-19 and unchanged (denial sJEdX v5, appeal cPTdA v6, overturn QooQc v4). See ma_denial_stats_sources.csv. Coverage rules and rates are for Original Medicare, which Medicare Advantage plans must follow. Informational only — not medical, legal, or billing advice.