Prior Auth Transparency Tracker

Prior Authorization Denial Rates by Insurer and Plan Type (2025 Data)

By Ajay Pillai, CEO, Aayur Solutions · Updated November 2026

Since 2026, insurers in Medicare Advantage, Medicaid and the federal ACA Marketplace must publish how often they deny prior authorization requests, how often denials are overturned, and how fast they decide. This page tracks those numbers by plan type and by insurer, and we will update it when each new year's data is published.

Quick answer: In 2025, large insurers denied 12% of standard prior authorization requests in Medicare Advantage, 14% in Medicaid managed care and 18% in ACA Marketplace plans. When denials were appealed, 67%, 47% and 43% were overturned. The median decision took about one day. Source: KFF analysis, August 13, 2026, of metrics posted by 14 large insurers covering about 71 million enrollees.

Denial Rates by Plan Type, 2025

Plan type	Standard requests denied	Expedited requests denied	Denials overturned on appeal (standard)	Median decision time (standard / expedited)
Medicare Advantage (6 insurers, 25 million enrollees)	12%	10%	67%	1 day / 0.4 days (about 10 hours)
Medicaid managed care (8 insurers, nearly 36 million enrollees)	14%	12%	47%	1 day / 0.8 days (about 19 hours)
ACA Marketplace, HealthCare.gov states (8 insurers, 10.8 million enrollees)	18%	16%	43%	0.9 days / 1 day

Source: KFF, analysis of 2025 metrics posted on insurer websites under CMS-0057-F. Covers medical items and services, not prescription drugs. Overturn rates are for standard requests; KFF did not report expedited appeal results because few insurers provided them.

Highest and Lowest Denial Rates by Insurer, 2025

Within each market, denial rates varied widely between the large insurers KFF analyzed. These are the lowest and highest rates KFF reported for standard requests:

Market	Lowest standard denial rate	Highest standard denial rate	Appeal overturn rates KFF highlighted
Medicare Advantage	5% (Elevance)	17% (UnitedHealth Group)	Centene more than 90%; Kaiser Permanente 40%
Medicaid managed care	2% (L.A. Care Health Plan)	23% (Independence Health Group)	UnitedHealth Group 81%; others between 22% (CVS) and 48% (Molina)
ACA Marketplace	3% (GuideWell)	25% (Centene)	Centene 54%; Health Care Service Corporation 16%

The same insurer can look very different by market. UnitedHealth Group denied 17% of standard requests in Medicare Advantage, 11% in Medicaid managed care and 21% in the ACA Marketplace (KFF). That is why you should look up the plan, not just the parent company, when you estimate prior authorization work for a payer.

Parent companies include their subsidiaries: Centene includes Wellcare and Ambetter, Elevance includes Anthem and Wellpoint, CVS includes Aetna, and Independence Health Group includes AmeriHealth Caritas. KFF warns that insurers' rates are not directly comparable, because their mix of services and patients differs.

How This Compares With Medicare Advantage in 2024

Before insurers had to publish metrics, KFF analyzed CMS data for Medicare Advantage. In 2024, insurers made nearly 53 million prior authorization determinations and denied 7.7% of them. Only 11.5% of denials were appealed, and 80.7% of those appeals were overturned (KFF). The 2024 and 2025 figures come from different data sources and methods, so they shouldn't be read as a trend.

What the Federal Rule Requires

Who must report: Medicare Advantage organizations, Medicaid and CHIP fee-for-service programs and managed care plans, and insurers on the federal ACA Marketplace (CMS-0057-F). Self-funded employer plans and most commercial plans are not covered.
When: metrics for the prior year must be posted on the insurer's website by March 31 each year. The first reports, for 2025, were due March 31, 2026.
Decision deadlines: since January 1, 2026, Medicare Advantage, Medicaid and CHIP plans must decide standard requests within 7 calendar days and urgent requests within 72 hours, and must give a specific reason for every denial.
Next step: plans must offer a prior authorization API for electronic requests by January 1, 2027.

What the Data Doesn't Show

Percentages only. Insurers don't have to report how many requests they received, so a 0% can't be told apart from missing data.
No breakdown by service. You can't yet see which procedures or drugs are denied most.
Medians hide delays. Half of all requests took longer than the median, and insurers don't report how many missed the deadline.
Few denials are appealed. Research cited by KFF shows denials are rarely appealed in Medicare Advantage, Medicaid managed care or the ACA Marketplace, even though many appeals succeed. The 2025 metrics don't include how many appeals were filed.

KFF reports that CMS has proposed adding request counts and standard denominators, and since July 2026, states must report prior authorization metrics for their Medicaid managed care plans to CMS, including the total number of requests.

What this means for your practice (illustrative, not client data): a practice that submits 100 standard prior authorization requests a month to an ACA Marketplace plan with an 18% denial rate could expect about 18 denials. If it appeals all of them and the plan overturns 43%, it would recover approvals on about 8, so about 10 services a month would stay denied. Appealing is often worth it; tracking your own denial and overturn rates by payer tells you where.

Physicians also report the cost on their side: an average of 40 prior authorizations per physician per week, taking 13 hours of physician and staff time (AMA 2025 survey). For how to cut that work, see our prior authorization guide.

Frequently Asked Questions

In 2025, large insurers denied 12% of standard prior authorization requests in Medicare Advantage, 14% in Medicaid managed care and 18% in ACA Marketplace (HealthCare.gov) plans, according to KFF's analysis of the metrics insurers must now publish.

It depends on the market. Among the large insurers KFF analyzed for 2025, the highest standard denial rates were UnitedHealth Group in Medicare Advantage (17%), Independence Health Group in Medicaid managed care (23%) and Centene in the ACA Marketplace (25%). KFF cautions that insurers' figures are not directly comparable, because their mix of services and patients differs.

In 2025, denials of standard requests that were appealed were overturned 67% of the time in Medicare Advantage, 47% in Medicaid managed care and 43% in the ACA Marketplace (KFF). Research cited by KFF shows denials are rarely appealed.

The median time for a standard request was about one day in all three markets in 2025. Federal rules now require Medicare Advantage, Medicaid and CHIP plans to decide standard requests within 7 calendar days and urgent requests within 72 hours, starting January 1, 2026.

The CMS Interoperability and Prior Authorization final rule (CMS-0057-F) requires Medicare Advantage organizations, Medicaid and CHIP programs and plans, and insurers on the federal ACA Marketplace to post prior authorization metrics on their websites each year. The first reports, covering 2025, were due by March 31, 2026.

No. The CMS rule does not cover self-funded employer plans or most fully insured commercial plans, so there is no public prior authorization data for them.

Sources

Figures checked against the linked sources on November 9, 2026. Educational content only. See our methodology.

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