Prescription drug denials by private insurers in the United States jumped 25% from 2016 to 2023, according to a new analysis of more than 4 billion claims, a practice that has contributed to rising public outrage about the nation’s private health insurance system.

The report, compiled for The New York Times by medical data company Komodo Health, shows that denial rates rose from 18.3% to 22.9%. The rejections went up across many major health plans, including the country’s largest private insurer, UnitedHealthcare.

The data offers a rare look into the largely hidden world of rejected insurance claims. While some government-funded health plans are required to publish their denial rates, most private insurers keep that information confidential. Komodo draws from private databases that collect denial details from pharmacies, insurers and intermediaries.

Experts who have studied denials said the skyrocketing costs of popular new weight-loss medications and greater automation of the claims process with artificial intelligence may have contributed to the rising rejection rates.

— The New York Times