Appealed Prior Authorization Denials Are Often Overturned, but Reversal Rates Range from 16% to 93% by Insurer

Patients who challenge a health insurer's refusal to cover care often win, yet few ever try, according to a Bloomberg analysis published September 14. The report found that about half of prior authorization denials are reversed when appealed, and as many as nine in 10 in some plans, and it questioned why insurers deny so many doctor-ordered services in the first place.

The findings echo newly public insurer data. A KFF analysis of insurer prior authorization data, released in August, looked at 2025 figures and found that 67% of appealed denials were overturned in Medicare Advantage, 47% in Medicaid managed care, and 43% in Affordable Care Act (ACA) marketplace plans sold through HealthCare.gov.