A recent study of denials by health insurance companies in New York has found that the percentage of denials overturned on external review increased from 38% in 2019 to 52.5% in 2025. The study also found that the percentage of denials varied by service, with nearly 80% of denials of home health services and 61% of denials of substance abuse or addiction services overturned on appeal.
Among the reasons for inappropriate denials listed by the researchers are outdated clinical criteria, ambiguous coverage rules, and inappropriate insurer behavior.
The study was published in JAMA Internal Medicine and reported in Axios Vitals.
Axios also reported on research conducted by IQVIA Holdings showing that 70% of all attempts to fill a new branded medicine prescription through commercial insurance were initially denied in 2025, up from a 57% denial rate in 2021. The research reported that patients are increasingly relying on appeals to gain approvals for prescriptions, but that the average time for prescription approvals had increased from 12 days in 2021 to 16 days in 2024. The researchers concluded that these “extended delays can disrupt treatment plans, leading patients to switch therapies, remain on existing medications, or defer treatment altogether.”
The Axios Vitals article is linked here and the IQVIA research is linked here.
The attorneys at Whatley Kallas, LLP have likewise found that health insurers routinely inappropriately deny and underpay claims and we pursue these claims on behalf of many of our provider clients.