Medicare Prior Authorization: What It Is, When It Applies, and How to Appeal a Denial

Prior authorization (PA) is a requirement by Medicare Advantage plans that you obtain plan approval before receiving certain medical services, procedures, or medications. It is one of the most significant differences between Medicare Advantage and Original Medicare -- and one of the most common sources of frustration for beneficiaries and providers.

Prior authorization means your Medicare Advantage plan must approve a service before you receive it (or before the plan will pay for it). The plan reviews clinical information to determine whether the service is medically necessary according to its coverage criteria.

Original Medicare does not require prior authorization for most services -- this is an important distinction. If you have Original Medicare with Medigap, you generally do not face prior authorization barriers.

Prior authorization requirements vary by plan, but commonly include:

• Inpatient hospital admissions (non-emergency)
• Skilled nursing facility admissions
• Inpatient rehabilitation
• Home health services
• Durable medical equipment (power wheelchairs, hospital beds)
• Specialty medications (especially high-cost biologics and specialty drugs)
• Advanced imaging (MRI, CT, PET scans)
• Certain surgical procedures
• Outpatient behavioral health services
• Certain specialist referrals (in HMO plans)

Your provider typically handles this: In most cases, your doctor or hospital submits the prior authorization request on your behalf. They provide clinical documentation supporting medical necessity.

Timeline: Plans must respond to standard prior authorization requests within 14 days. For urgent requests, the plan must respond within 72 hours.

What the plan reviews:

• Medical records and clinical notes
• Test results and imaging
• Treatment history
• Whether the service meets the plan's coverage criteria

If your prior authorization request is denied, you have several options:

Your doctor can request a peer-to-peer review -- a direct conversation between your doctor and the plan's medical reviewer. This often resolves denials when the clinical rationale is explained directly.

You have the right to appeal a prior authorization denial. File an appeal with your plan within 60 days of the denial notice.

Expedited appeal: If waiting for a standard appeal would seriously jeopardize your health, request an expedited appeal -- the plan must respond within 72 hours.

If your internal appeal is denied, you can request an external review by an Independent Review Entity (IRE) -- a third party not affiliated with your plan. The IRE's decision is binding on the plan.

If the IRE upholds the denial, you can request a hearing before an Administrative Law Judge (ALJ), then appeal to the Medicare Appeals Council, and ultimately to federal court.

CMS has implemented significant prior authorization reforms for Medicare Advantage plans:

2023: Plans must provide specific clinical reasons for denials and cannot deny coverage for services that meet Medicare coverage criteria.

2024: Electronic prior authorization requirements -- plans must implement electronic PA systems to speed up the process. Plans must also report PA data to CMS annually.

Continuity of care: When you switch MA plans, the new plan must honor prior authorizations from your old plan for at least 90 days.

• Ask your doctor's office to handle PA requests -- they have experience with the process
• Keep records of all PA requests, approvals, and denials
• Request expedited review if your condition is urgent
• Appeal every denial -- many denials are overturned on appeal
• Contact your plan's member services if you need help understanding a denial

We do not offer every plan available in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options.