Medicare Prior Authorization — PA
A rule used by Medicare Advantage and some Part D plans that requires plan approval before certain services, drugs, or equipment are covered.
Official source: cms.gov
## What it is
Prior Authorization (PA) is a process where a Medicare Advantage (Part C) plan or Part D plan must approve a service, procedure, drug, or device before it will pay. Original Medicare does not use PA for most services.
## Where PA usually applies
- Specialist visits (some plans). - Outpatient procedures such as colonoscopies or pain procedures. - Inpatient hospital admissions. - Imaging (MRI, CT, PET scans). - Durable Medical Equipment (DME) like power wheelchairs or hospital beds. - Specialty medications and biologics. - Skilled nursing facility admissions.
## 2026 rules speeding things up
Under CMS rules strengthened in recent years, Medicare Advantage plans must respond:
- Within **72 hours** for expedited (urgent) requests. - Within **7 days** for standard (non-urgent) requests.
Plans that miss these deadlines must approve the request automatically in many cases.
## How to appeal a PA denial
1. Request a **peer-to-peer review**: your doctor talks directly with the plan's medical reviewer. 2. File a **reconsideration** with the plan in writing. 3. If denied, escalate to an **Independent Review Entity (IRE)**. 4. Further appeals go to an Administrative Law Judge (ALJ), the Medicare Appeals Council, and federal court.
## Why this matters when choosing a plan
If you have complex or chronic conditions, heavy PA requirements can delay care. Many people with serious health needs prefer Original Medicare plus a Medigap plan because PA is rare in Original Medicare.
## Tip
Ask the plan for a written list of services that require PA before you enroll. Compare across plans during the Annual Enrollment Period (AEP).
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Frequently asked questions about Medicare Prior Authorization
Does Original Medicare require prior authorization?+
Rarely. Original Medicare uses PA only for a small list of services such as certain DME and a few outpatient procedures.
How long can a Medicare Advantage plan take to decide?+
72 hours for urgent requests and 7 days for standard requests, under current CMS rules.
Can I appeal a prior authorization denial?+
Yes. Start with a peer-to-peer review, then file a written reconsideration with the plan. Further appeals go to an Independent Review Entity and beyond.
Does prior authorization apply to prescription drugs?+
Yes. Many Part D plans require PA for specialty drugs, high-cost medications, and some controlled substances.
Why does Medicare Advantage use PA at all?+
Plans use PA to manage costs and confirm medical necessity. The trade-off is faster paperwork in Original Medicare versus extra benefits and lower premiums in Medicare Advantage.
Source: cms.gov