Does Medicare Require Prior Authorization? What Changed for 2026

What prior authorization actually means

Prior authorization (sometimes called pre-authorization, prior approval, or pre-certification) is a requirement to get a service, item, or drug approved before you receive it. If approval is required and not obtained, the claim can be denied and you could be left paying the bill.

Important: prior authorization is a coverage-decision step, not a guarantee of payment. Even an approved request still runs through your normal cost-sharing. Under Original Medicare Part B, for example, you generally pay the annual deductible of $283 for 2026 and then 20% coinsurance of the Medicare-approved amount for most covered services.

• It is requested by your doctor, supplier, or facility—not usually by you.
• It confirms the service meets Medicare's coverage rules before delivery.
• It does not change what you owe; deductibles and coinsurance still apply.
• Emergency care never requires prior authorization.

Original Medicare: limited prior authorization (historically)

For most of its history, Original Medicare has let you see any provider that accepts Medicare without getting a service pre-approved. Prior authorization existed only for specific categories that CMS identified as prone to improper billing.

Those long-standing requirements still apply in 2026 and are nationwide, separate from the new pilot described below.

• Certain durable medical equipment, prosthetics, orthotics, and supplies (DMEPOS) on the CMS Required Prior Authorization List—such as some power wheelchairs and lower-limb prosthetics.
• A defined set of hospital outpatient department procedures, including blepharoplasty, botulinum toxin injections, panniculectomy, rhinoplasty, vein ablation, cervical fusion with disc removal, implanted spinal neurostimulators, and facet joint interventions.
• Repetitive, scheduled, non-emergent ambulance transport in participating states.
• Outside these categories, Original Medicare generally has not required pre-approval.

New for 2026: the WISeR pilot in six states

Starting January 1, 2026, CMS launched the Wasteful and Inappropriate Service Reduction (WISeR) Model—a pilot that adds prior authorization to Original Medicare for the first time in a broad way. It runs through December 31, 2031, and CMS will use the results to decide whether to expand the approach.

The model applies in six states only: Arizona, New Jersey, Ohio, Oklahoma, Texas, and Washington. If you have Original Medicare and live outside these states, the WISeR requirements do not apply to you.

WISeR targets 17 services that CMS describes as vulnerable to fraud, waste, and abuse—examples include skin and tissue substitutes, electrical nerve stimulator implants, and knee arthroscopy for knee osteoarthritis. These are delivered in outpatient settings such as hospital outpatient departments, ambulatory surgery centers, physician offices, and the home.

• Excludes inpatient-only services.
• Excludes emergency services.
• Excludes services that would pose a substantial risk to patients if delayed.
• Providers in the pilot can submit a prior authorization request or instead undergo pre-payment medical review.
• Your right to appeal a Medicare coverage decision is unchanged.

Medicare Advantage: prior authorization is common

Medicare Advantage (Part C) plans are private plans that can—and routinely do—require prior authorization. Nearly all Medicare Advantage enrollees are in plans that require prior authorization for at least some services, often including hospital stays, skilled nursing, imaging, and certain procedures. Exactly what needs approval varies by plan, so check your plan's documents.

A federal rule (CMS-0057-F) tightens these processes with a compliance date of January 1, 2026. The changes are designed to make decisions faster and more transparent.

• Standard (non-urgent) decisions must be returned within 7 calendar days.
• Expedited (urgent) decisions must be returned within 72 hours.
• Denials must include a specific reason.
• An approved authorization stays valid for the full course of treatment.
• Plans must report data on approvals, denials, and appeals.

Part D and drug coverage

Medicare Part D prescription drug plans—and the drug coverage built into most Medicare Advantage plans—can require prior authorization for specific medications, often higher-cost or specialty drugs. Whether a given drug needs approval depends entirely on your plan's formulary, so requirements vary by plan.

Separately, Part D cost protections continue in 2026: once your out-of-pocket spending on covered drugs reaches the annual cap of $2,100, you pay nothing more for covered Part D drugs for the rest of the year. The 2026 national base beneficiary premium is $38.99 per month.

How to protect yourself

• Ask your provider whether a service needs prior authorization before it's scheduled—especially in Arizona, New Jersey, Ohio, Oklahoma, Texas, or Washington under WISeR.
• If you're in Medicare Advantage, read your Evidence of Coverage for the list of services that require approval.
• Get any approval in writing and keep a copy.
• If a request is denied, you have the right to appeal—follow the instructions on the denial notice.
• When in doubt, confirm details with official Medicare resources rather than relying on a single source.