CMS updates prior authorization transparency guidance

The Centers for Medicare & Medicaid Services (CMS) has issued updated guidance to strengthen the enforcement of federal prior authorization transparency requirements. This move follows concerns raised by the American Medical Association (AMA) regarding how health plans disclose authorization requirements and outcomes. The AMA reported that many plans made information difficult to find, hard to understand, or incomplete, sometimes burying data behind portals or providing overly complex billing lists.

A KFF analysis of 14 insurers representing approximately 71 million enrollees found that denial rates vary significantly across different markets. In 2025, Medicare Advantage insurers denied 12% of standard requests, Medicaid managed care insurers denied 14%, and ACA Marketplace insurers denied 18%. Denial rates among specific companies showed wide ranges, such as 5% to 17% for Medicare Advantage plans and 3% to 25% for ACA Marketplace plans.

While many denials are overturned upon appeal—with approximately 67% of Medicare Advantage denials being reversed—the KFF report notes that prior authorization denials are rarely appealed. Additionally, the lack of a standardized format for publishing data makes it difficult for consumers to compare insurer performance.