Prior Authorization Denial Rates Are Now Public: What KFF's First Transparency Report Shows

Payer-Level Standard and Expedited Denial Rates, Plus Appeal Overturn Rates, Published for the First Time Under a 2024 CMS Rule

Rcmaxis Billing & Policy Update  ·  Posted November 1, 2026  ·  Source: KFF analysis of CMS-mandated payer metrics, published August 13, 2026

What's Changing and When

A 2024 CMS final rule required payers across Medicare Advantage, Medicaid and CHIP managed care, and the ACA federally facilitated Marketplace to start publicly posting prior authorization metrics, with the goal of creating accountability for how often, and how predictably, these plans actually say no. KFF published the first full analysis of that data on August 13, 2026, covering standard and expedited requests submitted in 2025. This is the first time billing teams and practices have had a government-mandated, apples-to-apples look at denial behavior across plan types, rather than relying on anecdote or a single payer's own self-reported numbers.

The headline finding is a clear ranking by plan type. Medicare Advantage insurers denied 12% of standard prior authorization requests and 10% of expedited requests. Medicaid managed care insurers denied 14% standard and 12% expedited. ACA Marketplace insurers denied 18% standard and 16% expedited, the highest denial rate of the three categories CMS tracks. Appeals also succeed at meaningfully different rates by plan type: 67% of appealed Medicare Advantage denials get overturned, compared with 47% for Medicaid managed care and 43% for ACA Marketplace, which tells its own story about how aggressively each plan type's initial denial decisions actually hold up under review.

The Insurer-Level Numbers Worth Tracking

Individual insurer rates vary far more than the plan-type averages suggest, which is exactly why this data is useful at the payer level and not just the category level. Among Medicare Advantage insurers, standard denial rates ranged from 5% (Elevance) to 17% (UnitedHealth Group). Among Medicaid managed care insurers, the spread was wider still: 2% (L.A. Care Health Plan) to 23% (Independence Health Group). ACA Marketplace showed the same pattern, from 3% (GuideWell) up to 25% (Centene) on standard requests, and Centene also posted the highest ACA expedited denial rate at 23%.

If your practice contracts with payers at the high end of these ranges, specifically UnitedHealth Group in Medicare Advantage, Independence Health Group or CareSource in Medicaid managed care, and Centene across both Medicaid and ACA lines, that's a concrete signal to prioritize those payer relationships in your own prior authorization and appeals workflow. A payer with a published 20%+ denial rate and a sub-50% appeal overturn rate is telling you, in its own reported numbers, that initial denials from that plan deserve more documentation up front, not less.

What to Do With This Data

Pull your own practice's denial and overturn rates by payer and compare them against these published benchmarks. If your Medicare Advantage denial rate from a specific insurer runs well above 12%, or your appeal success rate runs well below 67%, that's a documentation or workflow gap worth investigating before assuming it's just "how that payer is." Conversely, if your numbers already track close to or better than these benchmarks, that's a useful data point to cite the next time a payer contract negotiation comes up.

Our prior authorization guide covers the broader appeal and documentation workflow this data should inform, and our Medicare Advantage billing guide walks through the plan-specific billing patterns tied to the payer category with the best appeal odds in this release.