Reduction Seen in Services Following Launch of Prior Authorization Pilot Program

TUESDAY, Nov. 10, 2026 (HealthDay News) — Following the launch of a model pilot program that requires prior authorization for 41 services and encourages artificial intelligence use in the prior authorization process, there was a reduction in use of the services targeted by the program, according to a research letter published online Oct. 26 in the Journal of the American Medical Association.

Hannah T. Neprash, Ph.D., from the University of Minnesota in Minneapolis, and Michael L. Barnett, M.D., from Brown University in Providence, Rhode Island, examined changes in service use following introduction of prior authorization requirements under the Wasteful and Inappropriate Service Reduction (WISeR) model pilot program that requires prior authorization for services considered vulnerable to fraud, waste, and abuse. The study involved more than 310 million patient records from more than 2,198 hospitals and 49,300 clinics. The number of traditional Medicare encounters with billed services requiring prior authorization under the WISeR model at the state-month level was examined as the primary outcome. A difference-in-differences analysis was conducted comparing six states participating in WISeR to all other states and the District of Columbia in the two years before launch (2024 to 2025) versus the six months after (January to June 2026).

The researchers found that during the period after program launch, traditional Medicare utilization of WISeR services decreased differentially in WISeR states. There was a differential change of −109.6 monthly epidural steroid injection (ESI) encounters in WISeR states, representing a 15.0 percent reduction relative to baseline. A differential change of −56.3 monthly encounters was seen for non-ESI service encounters, for a 19.5 percent reduction relative to baseline.

“The key question we can”t yet answer is whether the care not received was wasteful or necessary,” Neprash said in a statement.

One author disclosed ties to Arnold Ventures; a second author disclosed ties to Blue Cross Blue Shield of Massachusetts; the study was funded by Arnold Ventures.

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