CMS prior authorization update: What providers need to know

CMS expands ASC prior authorization rules with the 2026 WISeR model. Learn what providers need to know to prepare and reduce claim denials.
Published October 9, 2025
Written by
Picture of Shelly L. Jude, RHIA, RHIT, HIT
Global Clinical Services Director
Picture of Megan Hillgard
Sr. Marketing Campaign Manager
Key takeaways

The Centers for Medicare & Medicaid Services (CMS) continues to refine its approach to prior authorization, underscoring its focus on reducing wasteful or inappropriate care while safeguarding beneficiary access. For Ambulatory Surgical Centers (ASCs), these changes highlight the importance of preparing for evolving rules. 

Prior authorization doesn’t add new documentation obligations – it simply moves the timing earlier in the process. By reviewing information before services are rendered, providers can resolve issues in advance, reducing claim denials and costly appeals. For now, participation in the ASC demonstration program is voluntary. But providers who bypass prior authorization will see their claims subject to prepayment medical review. 

The ABN process and claim reviews

The Advance Beneficiary Notice (ABN) remains an important safeguard for patients. It notifies beneficiaries when Medicare may deny coverage, shifting financial responsibility to them. If a service is likely to be denied as cosmetic, providers are encouraged to issue an ABN and append a GX modifier to the claim. Although not mandatory in all cases, the practice ensures that patients understand their liability and can make informed decisions. 

When Medicare is the primary payer, claims submitted with a GA modifier and no prior authorization will be suspended for documentation review. Providers may submit a prior authorization request (PAR), and if denied, forward the claim to secondary insurance. For dually eligible beneficiaries, Medicare must issue a denial before Medicaid will consider coverage. 

When another insurer is primary, providers must first submit claims to that payer. If denied, they can then submit to Medicare. In cases where coverage requirements are met, CMS may issue a provisional affirmative decision. 

Exclusions and appeals 

Certain claims are not subject to the ASC prior authorization demonstration. These include: 

  • Veterans Affairs claims 
  • Indian Health Services claims 
  • Medicare Advantage claims 
  • IME-only claims 
  • Railroad Retirement Board claims 

If a prior authorization request is not affirmed, it cannot be appealed directly. However, providers can resubmit with additional documentation. Once a claim is denied by the Medicare Administrative Contractor (MAC), it becomes an initial payment determination and follows the standard appeals process. CMS also has the authority to suspend the prior authorization process – either broadly or for specific services – which will be announced via the CMS website. 

Services requiring prior authorization 

Some services already require nationwide prior authorization, including: 

  • Blepharoplasty 
  • Botulinum toxin injections 
  • Panniculectomy 
  • Rhinoplasty 
  • Vein ablation procedures 

Looking ahead, CMS will launch the Wasteful and Inappropriate Service Reduction (WISeR) Model on January 1, 2026. This pilot program, rolling out in Arizona, New Jersey, Ohio, Oklahoma, Texas, and Washington, will add 17 service categories to the prior authorization list. Among them are nerve stimulators, cervical fusion, knee arthroscopy for osteoarthritis, percutaneous vertebral augmentation, and skin and tissue substitutes for non-healing wounds. 

Key takeaways for providers 

While providers may bypass prior authorization under the WISeR model, claims will then be subject to post-service, pre-payment review. Exemptions apply for inpatient-only procedures, emergencies, and services where delay could pose risk. Documentation of medical necessity remains central to success, and beginning in 2026, payers must provide specific reasons for denial. 

The WISeR model is only a pilot, but its future expansion is possible. For now, providers should familiarize themselves with the new requirements, monitor updates from CMS, and prepare for a broader shift toward early claims review as a standard practice. 

ASCs should also be aware of CMS’s plan to phase out Medicare’s Inpatient Only List. Learn how this change may impact reimbursement, safety, and workflows for healthcare providers. 

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