Senate Keeps Medicare AI Prior Authorization Pilot Running

Senate Republicans voted Thursday to preserve a controversial Medicare pilot program that deploys artificial intelligence to approve or deny medical services ordered by physicians, defeating a Democratic resolution 50 to 46.

The Centers for Medicare and Medicaid Services launched the Wasteful and Inappropriate Service Reduction (WISeR) Model on January 1, 2025. The six-year experiment operates in six states and applies prior authorization requirements to specific procedures including skin and tissue substitutes, electrical nerve stimulator implants, and knee arthroscopy for osteoarthritis.

Democrats invoked the Congressional Review Act to force a vote ending the program, which requires only a simple majority to pass. The party-line outcome ensures the pilot will continue as designed.

Why it matters

The vote marks a significant expansion of prior authorization into traditional Medicare, where the practice has historically been limited to some outpatient physician services and medical equipment. Private Medicare Advantage plans routinely use prior authorization for specialist visits and prescriptions, but traditional Medicare has operated with fewer restrictions. The experiment tests whether AI-driven gatekeeping can reduce costs without compromising care quality—a question with implications for millions of beneficiaries as Medicare faces long-term funding pressures.

Program details and concerns

CMS defends WISeR as necessary to test methods for preventing unnecessary services and protecting taxpayer dollars. However, critics point to early operational data suggesting the program creates substantial delays. According to research from Senator Maria Cantwell (D-Wash.), patients subject to WISeR prior authorization waited four to eight weeks for care their doctors recommended, compared to a previous average of approximately two weeks—a two-to-four-fold increase in wait times.

"It is bad enough that this is the state of affairs in Medicare Advantage, but now the Trump administration is trying to import insurance company tactics into traditional Medicare," Senator Ron Wyden (D-Ore.) said during floor debate.

Senator Patty Murray (D-Wash.) framed the vote as a political liability for Republicans: "I don't know any senior, Republican or Democrat, who asked President Trump to let AI decide if their doctor-recommended treatment was necessary."

Broader prior authorization scrutiny

The Senate vote comes as Congress examines prior authorization practices more broadly. The House Ways and Means Committee unanimously advanced legislation Wednesday aimed at streamlining prior authorization requirements in Medicare Advantage plans, signaling bipartisan concern about administrative burdens even as Republicans defended the WISeR experiment.

The pilot program will now run through 2031 unless Congress takes further action or CMS terminates it early.

These details were first reported by The Hill.