For decades, one of the clearest advantages of traditional Medicare over private Medicare Advantage plans was the absence of prior authorization. A patient in Original Medicare could see any participating doctor and schedule a covered procedure without waiting for an insurer to sign off first. That distinction is narrowing. Under a federal test now underway, Original Medicare requires advance approval for a defined list of procedures in six states, marking the first time in years that the government’s own program has imposed the kind of gatekeeping long associated with private plans.
The WISeR model and the six test states
The change comes through the Wasteful and Inappropriate Service Reduction model, a payment experiment run by the federal innovation office that designs and tests new ways of paying for care. Rather than apply nationwide, the model operates in a limited set of jurisdictions selected to test whether advance review reduces spending on services the agency considers prone to overuse. It is a pilot with a fixed lifespan, not a permanent rewrite of Original Medicare, and its results are meant to inform whether the approach spreads.
The model is one of several run by the Center for Medicare and Medicaid Innovation, which holds statutory authority to try alternative payment designs on a limited basis before any decision to expand them. That authority is why the requirement can appear in some states and not others without an act of Congress, and it is also why the arrangement carries an expiration date rather than standing as a permanent feature of the program.
The six participating states are Arizona, New Jersey, Ohio, Oklahoma, Texas, and Washington, with the model beginning in January 2026 and scheduled to run through 2031. Providers and suppliers in those states submit certain procedures for review before performing them. The design is technically voluntary, but a clinician who skips the prior-authorization step has the claim routed instead to prepayment review, which makes participation effectively unavoidable for the affected services.
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Which procedures need approval, and which do not
The model does not touch most of what Medicare pays for. It applies to a defined group of service categories that regulators flagged as carrying a higher risk of waste or improper billing, a list detailed in the Federal Register notice that established the program. Named targets include epidural steroid injections for pain, electrical nerve stimulator devices, and skin and tissue substitutes, procedures the agency describes as frequently delivered in ways that do not match clinical guidelines.
Emergency and inpatient hospital care fall outside the model, so a patient facing an urgent problem is not asked to wait for authorization. Routine visits, standard diagnostic tests, and the vast majority of outpatient services also proceed as before. The practical effect is concentrated: a beneficiary in one of the six states who is scheduled for one of the listed procedures may encounter a review step, while everyone else in traditional Medicare sees no change in how care is approved.
The review itself falls largely on providers rather than patients, since it is the doctor or supplier who submits the request and waits for a decision before proceeding. For the beneficiary, the visible consequence is timing. A procedure that once could be scheduled directly may now depend on an approval that arrives first, and a denial can push the patient and physician toward an appeal or an alternative course of treatment.
What it means for traditional Medicare’s promise
The significance of the model runs beyond the specific procedures on its list. Prior authorization has been one of the most common complaints about Medicare Advantage, where insurers use it to delay or deny care, and traditional Medicare’s freedom from it has been a central reason many enrollees choose to stay in the government program. Importing even a narrow version of that review into Original Medicare tests whether the tradeoff patients accepted in exchange for open access still holds.
Regulators frame the effort as a check on billing that inflates costs for the whole program, and the six-year window is designed to measure whether advance review saves money without blocking appropriate care. Critics counter that the same mechanism has produced delays and denials in the private market, and that layering it onto Original Medicare risks importing those problems. The pilot structure means the evidence, rather than the argument, is meant to decide the outcome.
That outcome is unresolved. The number of states, the list of covered procedures, and the model’s future all remain open, and whether the experiment stays confined to a handful of states or becomes a template for the rest of the country is the question the pilot exists to answer. Its scheduled run through 2031 gives regulators years of claims data to weigh before any decision to widen it, and no expansion is guaranteed at the end of that window.
For now, the divide between traditional Medicare and private plans is smaller than it was, but only at the edges. The program’s core structure is intact everywhere, and the new requirement reaches a specific set of procedures in specific places. The lasting question is whether a tool built to curb waste in six states eventually reshapes the coverage Original Medicare has long promised nationwide.
This article was produced with AI assistance and reviewed by The Money Overview editorial team.
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