KFF prior authorization metrics show 12 to 18 percent denial rates and high overturn rates on appeal

A KFF analysis published August 13, 2026, found that large health insurers denied between 12% and 18% of standard prior authorization requests in 2025, and that when patients or providers appealed, a large share of those denials were reversed. ^[1] The data come from a new federal requirement that insurers post their own prior authorization statistics online — but the required metrics cover medical items and services only, and specifically exclude prescription drugs. ^[1]

What the numbers show

On average, Medicare Advantage insurers denied 12% of standard prior authorization requests and 10% of expedited (urgent) requests. Medicaid managed care plans denied 14% of standard and 12% of expedited requests. Insurers on the Affordable Care Act federally facilitated Marketplace denied the most: 18% of standard requests and 16% of expedited requests. ^[1]

Appeals were uncommon, but often successful. KFF reported that 67% of appealed prior authorization denials were overturned in Medicare Advantage, 47% in Medicaid managed care, and 43% in the ACA federally facilitated Marketplace. ^[1] KFF describes denials as "rarely appealed." ^[2]

Individual insurers varied widely. Among six Medicare Advantage insurers analyzed, UnitedHealth Group denied the highest share of standard requests at 17%, while Centene denied the highest share of expedited requests at 13%. ^[2] In Medicaid managed care, Independence Health Group denied 23% of standard requests and CareSource denied 21% of expedited requests. ^[2] Among eight ACA Marketplace insurers, Centene denied the highest share of both standard (25%) and expedited (23%) requests. ^[2]

Decisions generally came fast. Median response time for standard requests was about one day across all three markets. For expedited requests, the median was about half a day in Medicare Advantage, just under one day in Medicaid managed care, and about one day in the ACA Marketplace. ^[1][2] Insurers are not required to report the range of response times or to break out results by type of service. ^[1]

The analysis drew on 14 insurers with at least 2.5% market share in their segments, covering 25 million Medicare Advantage enrollees (69% of enrollment), more than 35 million Medicaid managed care enrollees (54%), and nearly 11 million ACA federally facilitated Marketplace enrollees (74% of enrollment in those 28 states). ^[1] Fierce Healthcare put the combined total at roughly 71 million enrollees. ^[2]

Why it matters for patients

The most important caveat for people taking or considering GLP-1 medicines is that these figures do not include prescription drugs. The 2024 CMS rule requires insurers to report approval and denial rates aggregated for medical items and services, explicitly excluding prescription drugs. ^[1] So the 12% to 18% denial rates say nothing directly about how often coverage requests for semaglutide (Ozempic, Wegovy, Rybelsus) or tirzepatide (Mounjaro, Zepbound) are turned down. Those pharmacy-benefit numbers are not yet public under this rule.

What the data do illustrate is the general shape of the process patients run into. Denials happen at a meaningful rate, decisions usually arrive within a day or so, and appeals succeed often enough that a denial is not always the final word — 67% of appealed Medicare Advantage denials were overturned. ^[1] KFF also stresses that denials are rarely appealed in the first place. ^[2]

KFF found the transparency effort falls short of its goal. Researchers wrote that "difficulty locating and interpreting metrics on insurer websites and gaps in how (e.g., a standardized template that insurers are required to use) and what metrics (e.g., denominators and breakouts by service category) must be reported limit the usability of this information directly by the public." ^[1][2] Because insurers report only percentages and not counts, there is no way to tell whether a denial rate reflects a large or small number of requests. ^[2] And because everything is aggregated, there is no way to see which specific services are being denied. ^[1]

What happens next

Insurers were required to post the first year of data, covering calendar year 2025, by March 31, 2026. ^[1] The requirement is annual, so a second year of figures is due in 2027. ^[1] CMS has updated its reporting requirements and proposed new rules that would expand what insurers must disclose, standardize reporting methods, and make plans easier to compare; federal lawmakers and several states are also pressing for more prior authorization transparency, with some states using the data to limit authorization requirements for certain services. ^[2] Whether prescription drugs will be added to the required metrics is not stated in these sources.