How often does your insurer deny claims — and how often do patients win on appeal?
Under CMS-0057-F, Medicare Advantage, Medicaid/CHIP, and ACA marketplace insurers are now required to publicly post their prior-authorization metrics — approval rates, denial rates, and how often denials get overturned on appeal. The rule took effect January 1, 2026, with full public reporting required by March 31, 2026.
This explorer consolidates the public data that exists today — from KFF, HHS OIG, CMS reports, peer-reviewed studies, and court filings — so you can look up your insurer before you need to appeal.
All Medicare Advantage (industry average)
Medicare Advantage · 2024 data
Prior-auth denial rate
7.7%
Claim denial rate
13% vs. Traditional Medicare
Appeal overturn rate
75% of appealed denials
Only 11.5% of PA denials are appealed, leaving most denials unchallenged.
UnitedHealthcare
Medicare Advantage · 2024 data
Prior-auth denial rate
9% (post-acute care higher)
Claim denial rate
Higher than MA average
Appeal overturn rate
Up to 90% (nH Predict cases)
Subject of the Estate of Lokken v. UnitedHealth Group class action alleging algorithmic denials. Post-acute and skilled-nursing facility denials have been disproportionately overturned on appeal.
Humana
Medicare Advantage · 2024 data
Prior-auth denial rate
≈11% (industry-high)
Claim denial rate
Not published separately
Appeal overturn rate
Above MA average
Historically one of the highest PA request volumes among MA plans.
Aetna (CVS Health)
Medicare Advantage · 2024 data
Prior-auth denial rate
Within MA range
Claim denial rate
Not published separately
Appeal overturn rate
Not published separately
Anthem Blue Cross Blue Shield (Elevance Health)
Medicare Advantage · 2024 data
Prior-auth denial rate
Within MA range
Claim denial rate
Not published separately
Appeal overturn rate
Not published separately
Cigna Healthcare
Medicare Advantage · 2024 data
Prior-auth denial rate
Within MA range
Claim denial rate
Not published separately
Appeal overturn rate
Not published separately
PROPAT algorithm was the focus of ProPublica reporting in 2023 about rapid-fire denials.
Kaiser Permanente
Medicare Advantage · 2024 data
Prior-auth denial rate
Below MA average
Claim denial rate
≈6% (lowest among major insurers)
Appeal overturn rate
Not published separately
Integrated delivery model reduces PA friction; consistently lowest denial rates across plan categories.
Methodology. Numbers are drawn from publicly published KFF analyses, HHS OIG audits, CMS reports, peer-reviewed studies, and court filings. Where an insurer has not published a specific metric we mark it “Not published.” We do not estimate unpublished figures.
What changes March 31, 2026. The CMS Interoperability & Prior Authorization Final Rule (CMS-0057-F) requires Medicare Advantage, Medicaid/CHIP managed care, and ACA marketplace insurers to publicly post their PA approval, denial, and overturn-on-appeal rates annually. Commercial and ERISA self-funded plans are not covered by this rule.
Limits. Aggregate denial rates do not tell you whether your specific claim will be denied. Policy terms, medical necessity, documentation, and state-level protections all matter. This page is informational — not medical, legal, or coverage advice.
Context
Why this matters
The denial is not the final word. Public data consistently shows that appeals are underused, even though many denials are reversed when patients challenge them. In the ACA marketplace, fewer than 1% of denied in-network claims are formally appealed.
The new data is a lever, not an answer. Knowing your insurer denies 20% of claims doesn’t mean yours was wrongly denied. It does mean you should check whether the denial turns on missing paperwork, prior authorization, coding, coverage rules, or clinical criteria before giving up.
Commercial/employer plans are not covered. If you’re on an ERISA self-funded plan through your employer, your insurer is not required to publish these metrics. Your appeal rights under 29 CFR § 2560.503-1 are still intact — we factor those into every appeal letter regardless.
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Figures are drawn from publicly available KFF, HHS OIG, CMS, peer-reviewed, and court-filing sources — not from confidential insurer data. Individual outcomes depend on plan type, documentation, state law, and the specific denial reason. This page is informational only and is not legal, medical, or insurance-coverage advice.