What Exactly Is WISeR?

by Alvin Blackshear  |  Historian & Researcher  <ablackshear@gmail.com> 

A Deeper Look at Medicare's AI Prior Authorization Pilot

A lot of you wrote in after “Is AI Deciding Who Gets Healthcare?” asking the same question: okay, but where, and for what?  Fair ask. Here are the details.

The Basics

WISeR stands for Wasteful and Inappropriate Service Reduction. It's a six-year model run by Centers for Medicare & Medicaid Services' (CMS) Innovation Center, announced in June 2025 and live since January 1, 2026. Unlike Medicare Advantage, where prior authorization has been standard for years, WISeR marks one of the first real tests of AI-assisted prior authorization inside original (fee-for-service) Medicare, a program that has historically had almost none of it. CMS frames the goal as trimming fraud, waste, and abuse. Critics frame it as outsourcing coverage denials to vendors whose paychecks depend on how much they deny.

Which States

WISeR is currently running in six states, split across four Medicare Administrative Contractor jurisdictions:

●        New Jersey

●        Ohio

●        Oklahoma and Texas

●        Arizona and Washington

CMS chose these based partly on which states' MAC jurisdictions and existing local coverage rules made the model easiest to test cleanly. There's no public timeline yet for expanding beyond these six, but several health-finance analysts expect that if the pilot runs smoothly, CMS won't wait out the full six years before widening it.

Which Procedures

For the initial phase, WISeR covers 14 selected Medicare Part B services, all elective rather than emergency or first-line treatments. The list centers on categories CMS has flagged as historically vulnerable to overbilling or overuse, including:

●        Skin and tissue substitutes (grafts used in wound care)

●        Electrical nerve stimulator implants

●        Epidural steroid injections for pain management

●        Knee arthroscopy for osteoarthritis

CMS has said it may add services to this list as the model progresses. Notably excluded: inpatient-only services, emergency services, and anything CMS considers too risky to delay.

Who's Actually Doing the Reviewing

This is the detail that surprises people most: the “model participants” aren't providers or insurers; they're technology companies. CMS selected six of them to operate the AI/ML-driven review process across the six states: Cohere, Genzeon, Humata, Innovaccer, Virtix, and Zyter.

Here's roughly how it works. A medical provider can either submit a request for prior authorization before performing the service, or skip that step and submit the claim for a post-service, pre-payment review instead. If they go the prior-authorization route, the AI vendor is supposed to return a determination (an affirmation or non-affirmation) within about three days. Any non-affirmation (denial) has to go through a licensed clinician before it's finalized; CMS says the AI itself can't issue the final “no.”

The Part That Worries Critics

The vendors' compensation is tied, at least in part, to the savings their reviews generate, meaning the more claims they flag as non-payable, the more they can earn, adjusted against other metrics like accuracy and provider experience. Revenue-cycle experts have publicly guessed that a meaningful share of claims routed through WISeR (some estimates run around 25%) could end up denied. That incentive structure is central to why members of Congress introduced the Ban AI Denials in Medicare Act, aiming to shut the model down before it expands further.

CMS is also piloting a “gold-carding” feature, expected to roll out further details later in 2026, that would exempt providers with consistently clean approval histories from future prior-authorization requirements, an attempt to reward compliance rather than blanket every claim with review.

The Takeaway

WISeR is narrower than my original article may have implied: six states, 14 services, six named vendors, with a human clinician required to sign off on any denial. But the financial incentives baked into the model, and the fact that this is the first large-scale AI prior-auth experiment inside traditional Medicare, are exactly why it's worth watching closely as it expands.

Sources

CMS, “WISeR (Wasteful and Inappropriate Service Reduction) Model”: https://www.cms.gov/priorities/innovation/innovation-models/wiser

CMS, “WISeR Model Frequently Asked Questions”: https://www.cms.gov/priorities/innovation/files/document/wiser-model-frequently-asked-questions

CMS, “WISeR Fact Sheet”: https://www.cms.gov/files/document/wiser-fact-sheet.pdf

CMS, “WISeR Model Provider and Supplier Operational Guide”: https://www.cms.gov/priorities/innovation/files/wiser-provider-supplier-guide.pdf

Nick Hut, “The WISeR prior authorization model for Medicare is set to pose challenges for hospitals,” HFMA (Dec. 23, 2025): https://www.hfma.org/revenue-cycle/the-wiser-prior-authorization-model-for-medicare-is-set-to-pose-challenges-for-hospitals/

ASRA Update, “CMS Provides More Details on WISeR Prior Authorization Model” (Oct. 24, 2025): https://asra.com/news-publications/asra-update-item/asra-updates/2025/10/24/cms-provides-more-details-on-wiser-prior-authorization-model

Dinsmore & Shohl, “Is AI WISeR? CMS Models AI-based Prior Authorization Process in Six States” (Jan. 30, 2026): https://www.dinsmore.com/publications/is-ai-wiser-cms-models-ai-based-prior-authorization-process-in-six-states/

Moss Adams, “Medicare WISeR Model Requires Prior Authorizations in Six States” (Jan. 13, 2026): https://www.mossadams.com/articles/2026/01/medicare-wiser-model

DLA Piper, “CMS launches WISeR Model: What providers need to know” (2026): https://www.dlapiper.com/en/insights/publications/2026/01/cms-wiser-model

Center for Medicare Advocacy, “Early Reports on WISeR Model Are Troubling” (Mar. 26, 2026): https://medicareadvocacy.org/early-reports-on-wiser-model-are-troubling/

Congressional Research Service via Congress.gov, “Overview of the Medicare Wasteful and Inappropriate Service Reduction (WISeR) Model” (May 12, 2026): https://www.congress.gov/crs-product/IF13133

Medical Economics, “WISeR spending or unneeded delays in health care? Prior authorizations, AI in Medicare prompt concerns” (July 15, 2026): https://www.medicaleconomics.com/view/wiser-spending-or-unneeded-delays-in-health-care-prior-authorizations-ai-in-medicare-prompt-concerns