Medicare beneficiaries in six states now face a new step before receiving certain common orthopedic procedures. The Centers for Medicare and Medicaid Services launched the Wasteful and Inappropriate Service Reduction model, known as WISeR, on January 1, 2026, requiring prior authorization for knee arthroscopy in osteoarthritis cases and steroid injections for pain management. The model runs through December 31, 2031, and uses AI-assisted technology to screen claims before treatment, though licensed clinicians make all final coverage decisions.
How AI-assisted prior authorization changes the path to treatment
WISeR introduces something Original Medicare has largely avoided until now: a formal gate between a doctor’s recommendation and the procedure itself. Under the model, providers in the six participating states must submit documentation for medical-necessity review before performing knee arthroscopy for osteoarthritis or administering steroid injections for pain. The CMS model page explains that enhanced technology, including AI tools, supports this review process by flagging claims tied to services that the agency considers historically higher risk for waste, fraud, or abuse.
The practical effect for patients is a waiting period that did not previously exist in fee-for-service Medicare. According to the program’s official FAQ, providers can route documentation either to a selected WISeR participant or through a Medicare administrative contractor, depending on how they choose to engage with the model. Either way, the extra step adds time and administrative burden to procedures that many physicians consider routine. For a beneficiary with painful knee osteoarthritis who has been told an arthroscopic procedure could help, the new requirement means their surgeon’s office must first secure approval from a third-party reviewer whose compensation is tied to reducing unnecessary services.
That payment structure is itself a source of friction. CMS has stated in a press announcement that selected companies are paid based on reducing unnecessary services, creating a financial incentive that critics of prior authorization have long warned can lead to inappropriate denials. The agency has countered that concern by emphasizing that technology supports the review but final non-coverage decisions are made by licensed clinicians, not algorithms. CMS also notes that model participants are expected to follow Medicare coverage rules and clinical evidence, and that beneficiaries retain existing rights to appeal adverse determinations.
For clinicians, WISeR adds a new layer of documentation and workflow complexity. Practices must ensure that imaging, clinical notes, and prior conservative treatments are clearly recorded and submitted in a format that reviewers can assess quickly. Some offices may designate staff to manage WISeR submissions, much as they already do for Medicare Advantage or commercial-plan authorizations. Others, especially small orthopedic or pain practices, may struggle with the added overhead and face pressure to delay or forgo borderline procedures rather than risk denials.
What the six-state test is designed to prove by 2031
The WISeR model is structured as a test with a clear hypothesis: prior authorization, applied selectively to procedures with documented patterns of overuse, can cut wasteful spending without harming patients who genuinely need care. A Congressional Research Service brief confirms the January 1, 2026 start date, the six-state scope, and the December 31, 2031 end date, framing the effort as a time-limited experiment rather than a permanent policy change.
The specific procedures targeted were not chosen arbitrarily. CMS materials reference research into patterns of low-value musculoskeletal care, including a peer-reviewed analysis examining how frequently these services are performed without clear clinical benefit. Knee arthroscopy for osteoarthritis, in particular, has been the subject of clinical debate for years, with multiple trials questioning whether the procedure produces better outcomes than physical therapy alone for many patients. Steroid injections for chronic pain, while widely used, have also raised questions about long-term efficacy and potential overreliance when other noninvasive options may be appropriate.
A reasonable expectation is that prior-authorization volume in the six states will be highest early in the model period, as reviewers and providers calibrate their understanding of what documentation is sufficient to establish medical necessity. Over time, CMS will be watching several key metrics: changes in utilization rates for the targeted procedures, shifts toward alternative treatments such as physical therapy, overall spending trends, and any signals that necessary care is being delayed or denied. Patient outcomes, including complication rates and functional status, will be critical to determining whether reductions in use represent the elimination of low-value care or the creation of new access barriers.
If WISeR demonstrates that carefully designed, AI-assisted prior authorization can meaningfully reduce waste without harming patients, CMS could use the findings to justify expanding similar tools to other services or geographic areas. Conversely, if data show widespread delays, appeals, or adverse clinical consequences, the model may serve as evidence that aggressive utilization controls in traditional Medicare carry unacceptable trade-offs. Because the model is time-limited, CMS retains the option to end it as scheduled in 2031, modify its design, or translate only selected elements-such as specific documentation standards-into broader policy.
For now, beneficiaries in the participating states can expect more questions and more paperwork before certain orthopedic procedures move forward. The WISeR experiment will test whether those new hurdles simply trim away unnecessary interventions or instead erect a more consequential barrier between older adults and the pain relief they seek.
