Traditional Medicare has never had prior authorization the way commercial plans do. A handful of demonstrations touched hospital outpatient departments, durable medical equipment and ambulance transport, but a physician practice billing Part B for an office procedure has, until now, simply performed the service and submitted the claim. On January 1, 2026 that changes for practices in six states.
The Wasteful and Inappropriate Service Reduction model, which CMS calls WISeR, was announced by the CMS Innovation Center on June 27, 2025 and published in the Federal Register on July 1. It is a six-year model, running from January 1, 2026 through December 31, 2031, in Arizona, New Jersey, Ohio, Oklahoma, Texas and Washington. A pain management practice in Houston asked us last week whether this means every epidural steroid injection they do in January needs an authorization first. For traditional Medicare patients, from January 15, yes, or the claim will be reviewed before payment instead.
Key takeaways
- WISeR applies to traditional Medicare only, in six states, based on where the provider or supplier is located. Medicare Advantage patients are not in it.
- Prior authorization requests can be submitted from January 5, 2026 and the requirement applies to services furnished on or after January 15, 2026.
- Seventeen categories of services are in scope, including skin substitutes, epidural steroid injections, knee arthroscopy for osteoarthritis, cervical fusion and several nerve stimulator implants.
- Requesting authorization is technically voluntary, but the alternative is pre-payment medical review of every in-scope claim. Request it every time.
What is in scope
The model targets a specific list of services that CMS considers vulnerable to fraud, waste or low-value use, chosen because they have existing national or local coverage determinations to review against. The list CMS has published covers 17 categories:
- Skin and tissue substitutes, the same products whose office payment the CY2026 fee schedule moved to a flat rate per square centimeter.
- Electrical nerve stimulator implants, plus sacral nerve stimulation for urinary incontinence, phrenic nerve stimulators, vagus nerve stimulation, hypoglossal nerve stimulation for obstructive sleep apnea, and deep brain stimulation for essential tremor and Parkinson's disease.
- Epidural steroid injections for pain management, excluding facet joint interventions, and induced lesions of nerve tracts.
- Knee arthroscopy for knee osteoarthritis.
- Cervical fusion, percutaneous vertebral augmentation for vertebral compression fracture, and percutaneous image-guided lumbar decompression for spinal stenosis.
- Incontinence control devices and the diagnosis and treatment of impotence.
The model applies to traditional Medicare fee-for-service only. Medicare Advantage plans already run their own prior authorization. Inpatient-only services, emergency services and services where a delay would put the patient at risk are excluded. The state that matters is the state where the practice or supplier is located, not where the patient lives, so a Texas practice treating a Medicare patient who winters in Texas from Minnesota is in scope, and an Arkansas practice treating a Texas resident is not.
How it works
CMS contracted with technology companies, which it calls model participants, one or more per state. Each reviews requests using artificial intelligence and machine learning tools together with clinicians. The participant checks the request against existing Medicare coverage rules: national coverage determinations, local coverage determinations and Medicare policy. CMS has said that a non-affirmation can only be issued after review by a licensed clinician, and that the model creates no new coverage criteria. The participants are paid a share of the savings they produce, which is the part physician groups have objected to most loudly, and we understand why.
A practice has two choices for an in-scope service. It can request prior authorization and, if affirmed, submit the claim with the tracking number. Or it can skip the request and submit the claim, which then goes to pre-payment medical review, meaning the practice sends records and waits for a decision before payment. CMS says standard requests will typically be decided within three days and expedited requests within two. A non-affirmed request can be resubmitted with more documentation as many times as needed. Practices that consistently meet the coverage criteria are expected to be exempted from submitting requests under a gold-carding approach, though the affirmation threshold and timing are still being worked out.
| Step | Who | What to have ready |
|---|---|---|
| Identify in-scope service for a traditional Medicare patient at a location in a model state | Scheduler or authorization staff | Practice location, service code, payer type (traditional Medicare, not MA) |
| Assemble documentation | Clinical staff | The elements the applicable LCD or NCD requires: history, conservative treatment tried, imaging, wound measurements and prior applications for skin substitutes |
| Submit the request (from January 5) | Authorization staff | Through the channels the model participant for your state publishes; register for them in December |
| Track the decision | Authorization staff | Tracking number, date, affirmation or non-affirmation reason |
| Bill | Billing | Claim with the tracking number; or records for pre-payment review if no request was made |
What we think practices should actually do
Request the authorization. Every time. Pre-payment review is slower, ties up cash and puts the decision after the service has been furnished, when there is nothing to do about a non-affirmation except appeal. Prior authorization puts the decision before the procedure, when the patient can still be counseled and the documentation can still be strengthened. A non-affirmed request costs you a resubmission; a denied claim after pre-payment review costs you the procedure.
The documentation is the same either way. WISeR does not invent coverage rules; it enforces the ones in the LCDs that most practices never read. If your epidural steroid injection notes do not document the conservative therapy tried and failed, the duration of pain and the imaging correlation that the LCD calls for, you will get non-affirmations, and you would have gotten post-payment audits eventually anyway. Pull the LCD for each in-scope service you furnish and turn its requirements into a template. For knee arthroscopy, the coverage question is the one Medicare has asked since the national coverage determination on arthroscopic lavage and debridement: is the procedure for osteoarthritis alone, which is not covered, or for a documented mechanical problem such as a locking meniscal tear.
For skin substitutes the model interacts with the new flat payment rate. A product that will be paid at $127.14 per square centimeter from January (CMS corrected the October 31 figure in a notice published on November 28), and that now needs prior authorization in six states, is a different business than the same product was in 2024. Wound care practices in the model states need a product, pricing and documentation review before the first January application.
The exposure calculation
Before January, know what is at stake. Pull every in-scope service furnished to traditional Medicare patients in 2025 from a location in a model state, with volume and allowed amounts. A pain practice with two physicians might find 900 epidural injections at roughly $250 to $400 in allowed professional and facility components, or $300,000 or so of annual revenue now subject to review. A wound care practice might find 1,200 skin substitute applications; at the new rate the product revenue is far smaller than in 2025, but the application codes and the office visits around them still depend on the affirmation. Then estimate the staff time: an authorization request that takes 20 minutes to assemble, times the annual volume, tells you whether one person can absorb it or the practice needs to hire or outsource.
Questions we hear
Does this apply to our Medicare Advantage patients?
No. MA plans have their own prior authorization programs, which under the CMS prior authorization rule must decide standard requests within seven calendar days from January 1, 2026. WISeR is traditional Medicare only.
Our practice has locations inside and outside a model state. Which patients are in scope?
The location where the service is furnished decides. Services at your Ohio office are in the model; services at your Pennsylvania office are not, even for the same patient. Configure the authorization work queue by location, not by patient, and confirm the specifics with your MAC because the operational guidance is still being refined.
Can we appeal a non-affirmation?
A non-affirmed prior authorization request is not an appealable decision; it can be resubmitted with additional documentation, without limit. A claim denied after pre-payment review carries the normal Medicare appeal rights, starting with redetermination within 120 days. Our denial management team is building the WISeR tracking for the practices we support in the six states, and the documentation templates are part of our coding review for in-scope procedures.
What to do this month
- Confirm whether any of your practice locations are in one of the six states.
- List every in-scope service you furnished to traditional Medicare patients from those locations in 2025, with volume and revenue. That is the exposure.
- Download the LCDs for those services and build a documentation checklist for each.
- Identify the model participant for your state and register for whatever submission channel it offers before January 5.
- Review every in-scope procedure scheduled for January 15 onward and plan to submit the requests in the first week of January.
- Add a WISeR category to your denial tracking so non-affirmations are counted separately from other Medicare denials.
