When an orthopedic surgeon in one of six pilot states submits a request to perform knee surgery on a 72-year-old Medicare patient, the claim no longer goes straight to CMS for payment. Instead, it lands with a private technology vendor, which uses algorithms and clinical reviewers to decide whether the procedure should happen at all. That step, prior authorization, has been a fixture of private insurance and Medicare Advantage for years. As of January 2026, it has arrived in Original Medicare for the first time.
The program behind that shift is the Wasteful and Inappropriate Service Reduction model, or WISeR, a six-year experiment the Centers for Medicare & Medicaid Services launched at the start of this year. It requires prior authorization for 17 medical procedures in six states, with the test period running through 2031. Five months in, the pilot is already drawing sharp criticism from physicians, patient advocates, and members of Congress who see it as a fundamental change to how traditional Medicare operates.
How the pilot works
CMS laid the groundwork for WISeR in a summer 2025 policy update and formalized the program through a Federal Register notice reportedly published on or around July 1, 2025, which set the January 2026 effective date. The U.S. Government Accountability Office is understood to have reviewed the notice under the Congressional Review Act, a routine step for major federal rules intended to confirm a program’s procedural and legal footing.
Under the model, private technology vendors selected by CMS screen prior authorization requests before claims can be paid. Those vendors use a combination of automation and artificial intelligence to triage incoming requests: straightforward cases that clearly meet coverage criteria are designed to move through quickly, while borderline or complex cases receive closer human review. Emergency services are explicitly carved out, so patients needing urgent care should not face new delays. But routine and elective procedures on the 17-item target list now require pre-approval before Medicare will pay.
The vendor compensation model is where the program draws its sharpest criticism. According to the Federal Register notice, participating firms earn a percentage of what CMS defines as “averted spending,” adjusted by performance metrics that include timeliness and accuracy. CMS has not publicly detailed which section of the notice specifies the formula or its caps. In practical terms, the companies deciding whether to approve or deny authorization requests have a direct financial incentive tied to the volume of spending they help reduce.
Which procedures are affected
CMS has not published the complete list of all 17 targeted services in a single, easily accessible document. The full roster is embedded in the July 2025 Federal Register notice rather than in the agency’s primary press materials or its public-facing WISeR webpage. That gap has frustrated providers and policy analysts trying to assess the program’s reach across medical specialties.
Three of the 17 services can be confirmed through national coverage determinations that CMS has linked to the model:
- Arthroscopic lavage and debridement of the knee in patients with osteoarthritis, a procedure CMS has long subjected to detailed coverage criteria that limit its use to specific clinical scenarios.
- Sacral nerve stimulation for urinary incontinence, which carries its own clinical documentation requirements under existing Medicare rules.
- Certain electrical nerve stimulators, governed by a separate national coverage decision with rules on indications, trial periods, and medical necessity.
Each of these existing coverage policies will likely serve as the clinical benchmark WISeR reviewers use when deciding whether to approve or deny a request. The remaining 14 procedures have not been widely reported, and CMS has not responded to requests for a consolidated public list.
Why the medical community is pushing back
Prior authorization is already one of the most contentious issues in American health care. The American Medical Association has called it the single greatest administrative burden facing physicians and has publicly opposed WISeR’s introduction into Original Medicare. In a statement responding to the program’s announcement, the AMA warned that layering prior authorization onto traditional Medicare “threatens to delay care for the nation’s most vulnerable patients.” Specialty societies representing orthopedic surgeons and urologists, whose procedures appear on the target list, have raised similar objections, warning that the pilot could delay medically necessary care for older adults who chose traditional Medicare specifically to avoid managed-care restrictions.
Those concerns draw on hard data from Medicare Advantage, where prior authorization is already widespread. A September 2022 report from the Office of Inspector General at the Department of Health and Human Services (report OEI-09-18-00260) found that 13 percent of prior authorization denials in Medicare Advantage plans involved services that would have been covered under Original Medicare’s own rules. That finding suggested financial incentives, not clinical standards, were driving a meaningful share of denial decisions. Critics of WISeR argue the new pilot risks importing that same dynamic into traditional Medicare, with the added complication that vendors are paid based on how much spending they help avert.
CMS has pushed back on that comparison, emphasizing that WISeR’s performance metrics are designed to reward accuracy alongside cost reduction. But the agency has not published detailed conflict-of-interest protections specific to the vendor payment arrangement. It also remains unclear whether AI-assisted reviews will include human clinical oversight at every decision point or only at the appeal stage, a distinction that matters enormously for patients whose procedures are flagged for denial.
What patients and providers still don’t know
As of June 2026, several significant details about WISeR remain opaque. The exact names of the six participating states have not appeared in CMS’s primary public-facing materials, an unusual omission for a program that directly affects beneficiary access to care. No baseline utilization data for the 17 targeted services in those states has been released, making it difficult for outside analysts to judge whether the pilot is calibrated to address documented overuse or whether it risks sweeping in large volumes of clinically appropriate care.
The methodology behind “averted spending” calculations has not been explained in detail. It is unclear whether that figure will be derived solely from denied claims, from altered treatment plans, from shifts to lower-cost care settings, or from some combination. That ambiguity matters because it determines how strongly vendors are rewarded for aggressive denials versus clinically sound review.
CMS has also not published state-level estimates of how many beneficiaries or providers will be directly affected. Nor has the agency released operational data on the program’s first five months: how many requests have been submitted, how quickly decisions have been issued, or how often initial denials have been overturned on appeal. Those numbers will be critical in determining whether WISeR functions as a modest guardrail against waste or as a substantial new barrier to timely care for Medicare’s traditional enrollees.
What happens if the pilot expands to all of Original Medicare
WISeR is structured as a six-year experiment, but its implications reach well beyond the pilot states. If CMS determines the model reduces wasteful spending without harming patient outcomes, the agency has the authority to expand prior authorization requirements across all of Original Medicare. According to the most recent Medicare enrollment data published by CMS, more than 34 million people were enrolled in Original Medicare as of early 2025, meaning an expansion would touch a substantial share of the nation’s seniors and people with disabilities. If the pilot instead produces high denial rates, long wait times, or documented harm, it could become a cautionary case study about grafting managed-care tools onto a program built on open access to providers.
Congressional interest is already building. Several lawmakers have questioned whether CMS has the statutory authority to impose prior authorization through an innovation model rather than through legislation, and at least one bipartisan letter to CMS leadership has requested a full briefing on WISeR’s design and early results. The agency’s next scheduled update on the program’s performance could shape not just the pilot’s future but the broader debate over how Medicare controls costs without restricting the care its beneficiaries were promised.
David M. Keller is a finance writer based in Columbus, Ohio, covering personal finance and consumer-focused economic topics. He earned his degree in journalism from Ohio University and began his career reporting on local business and economic trends for a regional media outlet. Since then, he has contributed to a variety of online publications, focusing on clear, practical coverage of topics such as cost of living, debt, and everyday financial decision-making.
