KFF Analysis Finds Wide Gaps in Prior Authorization Denial Rates

A new analysis from KFF, a nonprofit health policy research organization that studies health care issues, finds that insurers denied at least 1 in 8 standard prior authorization requests in 2025 across three major coverage types: Medicare Advantage, Medicaid managed care, and the federally facilitated ACA Marketplaces. The report was published August 13, 2026, and is based on the most recent publicly available prior authorization data. Denial rates varied widely from insurer to insurer, according to KFF, and the organization also flags significant gaps in what the data can actually show consumers.

Prior authorization is a process health insurers use to require approval before they will cover certain services, procedures, tests, or medications. Insurers say it helps control costs and confirm that care is medically necessary, but it has also become one of the most common sources of delayed or denied care reported by patients and providers. Read the full KFF analysis here.

According to KFF's analysis of 2025 data, insurers denied at least 1 in 8 standard prior authorization requests across Medicare Advantage, Medicaid managed care, and the ACA Marketplaces. Individual insurer denial rates ranged well above and below that overall figure, meaning a plan member's real-world experience can look very different depending on which insurer, and sometimes which specific plan, they are enrolled in. KFF also notes that the data has real limitations: reporting requirements differ across the three markets, some insurers submit incomplete figures, and the aggregated numbers do not explain why a specific request was denied or what happened when a member appealed.

Key Takeaway

KFF reports that insurers denied at least 1 in 8 standard prior authorization requests in 2025 across Medicare Advantage, Medicaid managed care, and the ACA Marketplaces, but denial rates varied widely by insurer and the public data does not show why individual requests were denied. Medicare Advantage members and shoppers should treat this as a reason to ask plan-specific questions, not a reason to assume any one plan behaves like the national average.

Why This Matters for Medicare Advantage Enrollees

Medicare Advantage is a private insurance alternative to Original Medicare, and most Medicare Advantage plans use prior authorization for a wide range of services, including some imaging, hospital stays, skilled nursing care, and certain specialist referrals. Original Medicare, by contrast, generally does not require prior authorization for most covered services. The Centers for Medicare & Medicaid Services (CMS), the federal agency that regulates Medicare and Medicaid, has required Medicare Advantage insurers to publicly report some prior authorization data in recent years, which is part of what makes analyses like this one possible.

The KFF findings underscore something Senior Plan Path has consistently told readers: prior authorization requirements and denial patterns are not uniform across the Medicare Advantage market. A plan with a low monthly premium or strong extra benefits on paper can still carry a higher administrative burden if it applies prior authorization broadly or has a higher-than-average denial rate for the services a given member is likely to need, such as certain diagnostic tests or post-acute care. Because KFF's analysis notes that the underlying data does not capture denial reasons or appeal outcomes in detail, consumers still cannot fully predict how a specific plan will handle a specific medical situation before they need the care.

It's also worth noting what this analysis does not establish. KFF's report describes data limitations and reporting gaps, not findings of improper conduct by any named insurer. Differences in denial rates can reflect differences in plan design, the mix of services requested, documentation practices, and enrollee health needs, in addition to how strictly a given insurer applies its review criteria.

What Readers Can Do Before the Next Enrollment Period

For Medicare beneficiaries and the family members who help them choose coverage, the practical response to this kind of data is to ask more specific questions rather than to avoid Medicare Advantage altogether. When comparing plans, ask a licensed agent or the plan directly which services on your typical care list, such as imaging, home health, or a planned procedure, require prior authorization under that specific plan. Request the plan's prior authorization and appeals process in writing, and ask how long a decision typically takes and what happens if you need urgent care while a request is pending.

Every Medicare Advantage member also has the right to appeal a prior authorization denial, and plans are required to provide a way to file that appeal. If you or a family member has experienced a denial in the past year, that history is worth discussing with a licensed insurance agent during your next plan review, since it may point to a mismatch between your care needs and your current plan's utilization management practices. Readers who want fewer prior authorization requirements overall may also want to compare Original Medicare paired with a Medigap supplement policy against Medicare Advantage, since the two paths handle prior authorization very differently.

This article is a news analysis based on KFF's published research and is not medical or financial advice. Because prior authorization rules, denial patterns, and appeal processes vary by plan and can change from year to year, readers should confirm current details directly with a plan or a licensed Medicare agent before making enrollment decisions.