Payers ranked by prior authorization denial rates

Health insurers denied between 12% and 18% of standard prior authorization requests across Medicare Advantage, Medicaid managed care and ACA marketplace plans in 2025, with wide variation among the largest payers, according to a KFF analysis published Aug. 13.

CMS previously finalized a rule requiring certain insurers to publicly report prior auth metrics, including denial rates, processing times and appeal overturn rates. The first reports, covering 2025, were due March 31. The data is aggregated across all items and services, with no breakdown by service type, so there’s limited insight into what services are being approved or denied. Payers are also not required to report reasons for denials.

The rankings below only cover standard prior auth requests and they don’t include data for prescription drugs (though CMS has proposed a rule to require that information to be public as well). Denial rates for urgent requests, which are included in KFF’s analysis, were slightly lower across all markets.

Prior auth denials are rarely appealed, but when they are, a considerable share are overturned, including 67% for Medicare Advantage plans, 47% in Medicaid managed care and 43% in the ACA marketplace.

KFF cautioned that there is limitations in the new data that complicates direct comparisons between insurers. Payers are required to report only percentages, not the number of prior authorization requests they received or denied. A previous KFF analysis of Medicare Advantage found that the number of prior authorization determinations per enrollee was inversely related to the denial rate, meaning insurers that processed more requests denied a smaller share of them. As a result, the absolute number of denied requests per enrollee was similar across insurers with very different denial rates.

Comparisons are further complicated by gold carding programs, through which some insurers exempt providers with consistently high approval rates from prior auth requirements. Because those easy approvals are removed from the data, insurers that rely heavily on gold carding may report higher denial rates even though fewer patients are subject to prior auth overall.

Differences in enrollee populations, the mix of services covered and variations in how insurers reported the data also limit the usefulness of cross-insurer and cross-market comparisons, KFF noted.

Medicare Advantage prior authorization denial rates

1. UnitedHealth Group: 17%
2. Centene: 15%
3. Kaiser Permanente: 13%
4. CVS: 8%
5. Humana: 7%
6. Elevance: 5%

Medicaid prior authorization denial rates

1. Independence Health Group: 23%
2. CareSource: 20%
3. Centene: 18%
4. CVS: 17%
5. Molina: 11%
6. UnitedHealth Group: 11%
7. Elevance: 9%
8. L.A. Care Health Plan: 2%

ACA marketplace prior authorization denial rates

1. Centene: 25%
2. UnitedHealth Group: 21%
3. BCBS North Carolina: 18%
4. Oscar: 18%
5. Molina: 13%
6. Elevance: 10%
7. Health Care Service Corp.: 6%
8. GuideWell: 3%

Medicare Advantage prior authorization denials overturned on appeal

1. Centene: 93%
2. CVS: 89%
3. Elevance: 75%
4. Humana: 64%
5. UnitedHealth Group: 60%
6. Kaiser Permanente: 40%

Medicaid prior authorization denials overturned on appeal

1. UnitedHealth Group: 81%
2. Molina: 48%
3. Centene: 47%
4. Elevance: 36%
5. Independence Health Group: 36%
6. CareSource: 29%
7. CVS: 22%

ACA marketplace prior authorization denials overturned on appeal

1. Centene: 54%
2. Molina: 50%
3. BCBS North Carolina: 47%
4. Oscar: 43%
5. UnitedHealth Group: 38%
6. Elevance: 36%
7. GuideWell: 30%
8. Health Care Service Corp.: 16%