Traditional Medicare, also known as original Medicare, has historically required little in the way of pre-authorization for beneficiaries seeking services; pre-authorization was typically the domain of Medicare Advantage. But that has changed, as the Centers for Medicare and Medicaid Services (CMS) has implemented prior authorization requirements for certain traditional fee-for-service Medicare services in six states.
This change went into effect on January 1, 2026, as CMS starts to "test ways to provide an improved and expedited prior authorization process relative to original Medicare’s existing processes, helping patients and providers avoid unnecessary or inappropriate care and safeguarding federal taxpayer dollars," per a CMS press release. The model being implemented in 2026 builds on a change to prior authorizations rolled out by the Department of Health and Human Services (HHS) and CMS on June 23, 2025.
Six states — New Jersey, Ohio, Oklahoma, Texas, Arizona, and Washington — were selected to use the Wasteful and Inappropriate Service Reduction (WISeR) Model to perform prior authorization evaluations, CMS announced in a Federal Register notice. This applies to 17 services that CMS says "are vulnerable to fraud, waste and abuse."
The Trump Administration's continuing fight against fraud, waste and abuse
HHS and CMS secured an agreement among private insurance companies to "pledge to streamline and improve the prior authorization processes for Medicare Advantage, Medicaid Managed Care, Health Insurance Marketplace and commercial plans covering nearly eight out of 10 Americans." Separately, Humana announced a plan to reduce prior authorizations by one-third and wait times for others.
The introduction of the short list of Medicare services for prior authorization will test how well technologies such as machine learning and AI can streamline the prior authorization process. “CMS is committed to crushing fraud, waste, and abuse, and the WISeR Model will help root out waste in original Medicare,” said CMS Administrator Dr. Mehmet Oz.
As part of the goal of rooting out waste and fraud, the Justice Department conducted a 2025 National Health Care Fraud Takedown. Results were released on June 30, 2025, and included charges against more than 300 defendants who were accused of a range of health care fraud schemes.
One particular indictment can provide insight as to how or why some of the procedures/services were selected for the list. In one case, three defendants in Arizona allegedly conspired to give elderly Medicare recipients unnecessary skin grafts, known as "amniotic wound allografts." The defendants allegedly pocketed millions of dollars and billed for "more than over $1 billion in false and fraudulent claims to Medicare and other health benefit providers for these medically unnecessary allografts." To make matters worse, according to the indictment, the defendants are alleged to have targeted Medicare beneficiaries, many of whom were terminally ill in hospice care.
The WISeR Model and how the program will work
The WISeR Model (Wasteful and Inappropriate Service Reduction) is meant to test the use of enhanced technologies, such as AI and machine learning, to decrease "certain wasteful or low-value services shown to have little to no clinical, evidence-based benefit." CMS chooses services that "have been identified as particularly vulnerable to fraud, waste, and abuse, or inappropriate use."
Medicare beneficiaries should know that AI will not be determining if a procedure is approved or denied; a human being will be reviewing the information. "...while technology will support the review process, final decisions that a request for one of the selected services does not meet Medicare coverage requirements will be made by licensed clinicians, not machines," CMS explained.
The use of the model will not alter Medicare coverage or payment rules. While other services may be added to the model later, it explicitly "excludes inpatient-only services, emergency services, and services that would pose a substantial risk to patients if delayed," according to the CMS fact sheet.
Providers and suppliers of the services included in the prior review process can either submit a prior authorization request for the model’s selected items and services or go through a post-service/pre-payment medical review.
17 services to be subject to prior authorization
Here is the list of services that will go through a prior authorization process in New Jersey, Ohio, Oklahoma, Texas, Arizona, and Washington, between January 1, 2026, and December 31, 2031.
- Electrical nerve stimulators
- Sacral nerve stimulation for urinary incontinence
- Phrenic nerve stimulator
- Deep brain stimulation for essential tremor and Parkinson’s disease
- Vagus nerve stimulation
- Induced lesions of nerve tracts
- Epidural steroid injections for pain management
- excluding facet joint injections
- Percutaneous vertebral augmentation (PVA) for vertebral compression fracture
- Cervical fusion
- Arthroscopic lavage and arthroscopic debridement for the osteoarthritic knee
- Hypoglossal nerve stimulation for obstructive sleep apnea
- Incontinence control devices
- Diagnosis and treatment of impotence
- Percutaneous image-guided lumbar decompression for spinal stenosis
- Skin and Tissue Substitutes
- Application of bioengineered skin substitutes to lower extremity chronic non-healing wounds
- Wound Application of cellular and/or tissue based products (CTPs), lower extremities
Bipartisan backlash: Concerns over delays and AI
The new model has faced bipartisan criticism for potentially increasing delays. Rep. Suzan DelBene (D-Wash.) called it "baffling" that the administration would implement "the same delay tactics" in traditional Medicare that they previously criticized in Medicare Advantage.
From the right, Michael Baker of the American Action Forum expressed skepticism regarding the administration's promise to reduce hurdles. He warned that adding a "duplicative third party" using "untested artificial intelligence" could ultimately "increase the overall administrative burden and delay beneficiary care."
How common are prior authorizations in Medicare and Medicare Advantage?
As it stands, traditional Medicare requires prior authorization for a substantially smaller set of procedures and services than most Medicare Advantage plans. Medicare services that typically require prior authorization include certain outpatient hospital services, non-emergency ambulance transport, and durable medical equipment. For 2025, just under 628,243 prior authorization reviews for traditional Medicare beneficiaries were submitted to CMS, according to KFF. "This translates to about 2 prior authorization reviews per 100 traditional Medicare beneficiaries in 2024."
The situation is very different for Medicare Advantage plans. While they must cover all medically necessary services that original Medicare covers, for some services, MA plans may use their own coverage criteria to determine medical necessity. Almost all Medicare Advantage enrollees — 99% according to KKF — must obtain prior authorization for some services. These are typically higher-cost services, such as inpatient hospital stays, skilled nursing facility stays and chemotherapy. In 2024, 53 million prior authorization requests were submitted to Medicare Advantage insurers.
