Formulary-Related Insurance Denials of Single-Source Branded Drugs in the United States.

Formulary rejections of single-source branded drugs increased by 67.4% from 2018 to 2024, leading to delayed or absent treatment in over half of initial rejection cases.

• Why it matters: Limited access to timely treatment due to formulary exclusions and utilization management can negatively impact patient health outcomes and healthcare costs.
• What they did: Analyzing 2 million prescription attempts across various insurance plans using IQVIA data, the study estimated rejection rates, reasons, and subsequent medication fills within 90 days.
• The result: Rejections were common, especially in exchange and Medicaid managed care plans, causing an average delay of 12.2 days and resulting in no medication fill in nearly half of rejected cases, emphasizing the trade-off between cost control and access.