Medicare’s new experiment in prior authorization has cleared its most consequential political test to date.
On July 16, the Senate voted 46-50 along party lines against advancing a resolution to end the Wasteful and Inappropriate Service Reduction Model, CMS’ six-state test of technology-assisted prior authorization in traditional Medicare. Democrats behind the repeal effort argued the model lets contractors use AI to delay and deny seniors’ care; the administration has defended it as a crackdown on fraud, waste and abuse. The vote came about five weeks after the House Appropriations Committee passed an amendment by voice vote that would block funding for the program in fiscal 2027.
While the model survived, its future remains uncertain. The House amendment to defund it heads into this fall’s spending negotiations, one of its six contractors was ordered to submit a corrective action plan, and CMS has yet to release data on the model’s denials and appeals — the figures that could help settle the most contentious debates about the program.
The implications for the program stretch beyond the six pilot states. CMS has framed the model as a template for how private-sector technology could operate inside Medicare. With WISeR in its eighth month, here are eight questions that reveal what is known and unknown about the program.
1. What exactly is WISeR testing?
WISeR launched Jan. 1 and is set to run through Dec. 31, 2031. Vendors began accepting prior authorization requests Jan.5.It is the first CMS Innovation Center model in which technology companies are the only participants, testing whether tools such as AI and machine learning — paired with clinician review — can reduce spending on services CMS considers vulnerable to fraud, waste and abuse. The agency has described the model as a potential “roadmap” for bringing private-sector technology into Medicare operations.
The rationale behind the model rests on two numbers. CMS cites estimates that waste accounts for up to 25% of U.S. healthcare spending. And spending on the services WISeR targets varies widely by geography: in 2024, per-capita spending on model-covered services ranged from $202 in Ohio to $748 in Oklahoma, against a national average of $371, according to KFF. The variation was driven largely by skin substitutes, which are synthetic and tissue-derived products that are often applied to chronic wounds like diabetic foot ulcers.
2. Which states, services and providers are affected?
Six companies were selected, each assigned to a single state: Arizona, New Jersey, Ohio, Oklahoma, Texas and Washington. The companies review requests for care, applying existing Medicare coverage criteria in their assigned states.
For hospitals and physician practices in the six states, the model adds a review step for a short list of mostly outpatient procedures — among them skin and tissue substitutes, electrical nerve stimulator implants, knee arthroscopy for knee osteoarthritis, epidural steroid injections, cervical fusion and treatments for urinary incontinence and impotence. Inpatient-only services, emergency services and services that would pose substantial risk to patients if delayed are excluded. The model also gives providers a choice about when that review happens. They can ask for approval before treating the patient or treat first and have the claim reviewed before Medicare pays it. Each path has a trade-off. Asking first means knowing Medicare will pay before the procedure happens, but the patient waits on the decision. Treating first means no delay in care, but if reviewers later find the service didn’t meet Medicare’s criteria, the provider isn’t paid.
What Medicare covers and what it pays are unchanged, and the model does not affect Medicare Advantage.
3. Can AI alone deny a claim?
Not by design. Vendors’ technology screens requests against existing Medicare coverage criteria, but CMS requires that all recommendations of non-payment be “determined by appropriately licensed clinicians” — not by AI alone. Coverage decisions are due within 72 hours, or 48 hours for expedited requests.
Whether day-to-day practice matches that design has been a central question for the model’s critics. It is also a question that cannot yet be independently verified because CMS has not released first-year review data.
4. Do vendors profit from denials?
Participants earn a percentage of the “averted expenditures” associated with care their reviews screen out, adjusted for performance on measures that include provider experience. Critics say that structure pays companies to deny care.
Abe Sutton, director of the CMS Innovation Center, disputed that characterization before the model even launched. Contractors will not be incentivized to deny claims, he said during an October 2025 webinar co-hosted by the American Medical Association and the Innovation Center, but to “get the determination right.” He also emphasized that clinicians retain their existing appeal rights.
5. What happened in Washington state?
Early this year, providers in the state reported waiting 15 to 20 days for determinations against the 72-hour standard, according to an April letter to HHS Secretary Robert F. Kennedy Jr. from Sen. Maria Cantwell, who wrote that procedures typically completed within two weeks were taking four to eight weeks. The contractor has disputed the characterization of its wait times.
In late June, CMS ordered its contractor in the state to submit a corrective action plan. There are signs of improvement, though their scope is unclear. In a June statement to KUOWconfirming the corrective action plan, CMS said prior authorization turnaround — which averaged about five days over the program’s first four months — had since fallen to 1.7 days, inside the 72-hour standard, with pre-payment reviews averaging just over three days. The agency’s statement did not specify whether those figures describe Washington alone or all six states.
6. How has Congress responded?
Some of the loudest opposition has come from Washington Democrats. Sens. Patty Murray and Maria Cantwell co-led the resolution to overturn the model, introduced by Senate Finance Committee ranking member Ron Wyden of Oregon, arguing it delays medically necessary care and improperly lets AI systems override physicians’ judgment. Rep. Suzan DelBene has put it more bluntly, telling KUOW the model is “a Trojan horse for privatizing Medicare.”
7. Is the model working?
That question can’t yet be answered with public data. At just over seven months in, CMS has not released denial, appeal or overturn rates for the model. This lack of data has itself become a point of contention. In June, 31 House Democrats wrote to CMS Administrator Mehmet Oz, MD, requesting implementation data — including denial rates, appeals and turnaround times — by July 15.
Likely fueling the demand for data is the specific worry that WISeR’s denials could follow the pattern set in Medicare Advantage, where flawed denials mostly go unchallenged. In 2024, just 11.5% of denied prior authorization requests in MA were appealed — but 80.7% of those appeals were partially or fully overturned, according to KFF. Without published WISeR data, neither the critics’ warnings nor CMS’ assurances can be fully evaluated.
8. What should health system leaders be keeping an eye on?
The corrective action plan: How quickly the Washington vendor completes the plan’s requirements — CMS is reviewing progress every two weeks — will shape the model’s story in its most scrutinized state.
Gold carding: The concept is borrowed from state prior authorization reforms and commercial insurance, where clinicians with consistently high approval rates earn an exemption from review — the idea being that prior authorization should focus on outliers, not everyone. Beginning in July, CMS and its vendors implemented a similar process to automatically exempt providers from prior authorization and pre-payment review once they demonstrate compliance with Medicare coverage, coding and payment rules.
Exemptions are granted at the individual-provider level and subject to reevaluation, per the model’s operational guide. The numbers to watch: how many providers earn the exemption, and how fast.
Appropriations: The fiscal 2027 funding fight resumes this fall with the House amendment still in play. If it survives into a final spending bill, Congress could halt the model without ever repealing it.
Expansion — or not: CMS has said it will evaluate WISeR’s outcomes before considering geographic or procedural expansion and has framed a successful model as a potential blueprint for broader prior authorization reform in Medicare and potentially the private sector. Whether the agency releases the data that evaluation requires — and whether the model grows, shrinks or stands as it is — is the question that will determine whether WISeR stays a six-state experiment or becomes a template for Medicare at large.
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