Medicare's prior-authorization pilot test led to an immediate drop in use of services

by University of Minnesota

edited by Lisa Lock, reviewed by Andrew Zinin

Lisa Lock

Scientific Editor

Meet our editorial team
Behind our editorial process

Andrew Zinin

Chief Editor

Meet our editorial team
Behind our editorial process Editors' notes

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

peer-reviewed publication

trusted source

proofread

The GIST Add to Preferred Sources

For many years, traditional Medicare has operated almost entirely without prior authorization, a requirement that clinicians obtain approval before certain services will be covered. The practice is controversial because it adds paperwork, outside review and other barriers that can delay or deny coverage for recommended treatment. While prior authorization is widely used by commercial insurers and Medicare Advantage, traditional Medicare has historically almost never required it.

That changed in January 2026 with the launch of a new federal pilot program. Called WISeR (Wasteful and Inappropriate Service Reduction), the program is a six-year pilot that requires prior authorization for a set of services considered vulnerable to fraud, waste and abuse in six states: Arizona, New Jersey, Ohio, Oklahoma, Texas and Washington. The companies contracted to conduct the prior authorizations, which are mostly technology firms, are encouraged to use artificial intelligence in their prior authorization review processes. WISeR has been controversial, but until now there has been no evidence on its effects.

A new study from the University of Minnesota School of Public Health (SPH) and Brown University School of Public Health provides the first evidence about the pilot program. Using Epic Cosmos, a large electronic health record data set covering more than 300 million patient records nationwide, the researchers compared monthly use of WISeR-targeted services among traditional Medicare patients in the six participating states with use in all other states and the District of Columbia. The comparison covered the two years before the program's launch and the first six months after.

The study, published in JAMA, found:

• Use of services targeted by the pilot program fell. Compared with trends in states outside the pilot, epidural steroid injections for back pain—the highest-volume service in the model—declined 15%, while other targeted services declined about 20%.
• Services used as a control group showed no significant change. Services that were originally slated for WISeR but never implemented showed no decline in use, supporting the conclusion that prior authorization itself, and not some other trend, drove the decline.
• The effect was largest right after launch and weakened over time. For epidural steroid injections, the reduction fell from about 21% in the first quarter of 2026 to about 9% in the second quarter. For other services, it went from 21% to 18%. This "wearing off" effect may reflect the time it took to work out the kinks of a new workflow, the gradual learning process for clinicians to meet prior authorization requirements, or some of both.

"Traditional Medicare has operated almost entirely without prior authorization, so WISeR represents a major change in how older adults access care," said Hannah Neprash, SPH associate professor and lead author. "Our early evidence shows that these requirements had an immediate effect, with noticeable drops in use of targeted services in participating states.

"The key question we can't yet answer is whether the care not received was wasteful or necessary. As the Centers for Medicare and Medicaid Services considers whether to continue or expand this model, understanding its effects on patients, clinicians and Medicare spending should be a top priority."

"As a physician, I know how burdensome prior authorization can be," said Michael Barnett, professor at Brown University School of Public Health and study co-author. "The early results suggest that doctors may be adapting rapidly to the new system. We need to watch closely to see if the additional work of prior authorization justifies what might be relatively little change in who gets care."

Study authors recommend that future work should examine whether these effects last over the model's six-year run, and how WISeR affects the appropriateness of care, patient outcomes, clinician burden and Medicare spending.

Publication details

Hannah T. Neprash et al., Changes in Service Use Following the Introduction of AI-Enabled Prior Authorization in Medicare, JAMA (2026). DOI: 10.1001/jama.2026.21230

Journal information: Journal of the American Medical Association

Key medical concepts

Epidural Steroid InjectionBack Pain

Clinical categories

Healthy aging Provided by University of Minnesota Who's behind this story?

Lisa Lock

BA art history, MA material culture. Former museum editor, paramedic, and transplant coordinator. Editing for Science X since 2021. Full profile →

Andrew Zinin

Master's in physics with research experience. Long-time science news enthusiast. Plays key role in Science X's editorial success. Full profile →

Citation: Medicare's prior-authorization pilot test led to an immediate drop in use of services (2026, October 27) retrieved 27 October 2026 from https://medicalxpress.com/news/2026-10-medicare-prior-authorization.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.