Prior authorization is one of the most frustrating parts of being on a Medicare Advantage plan. The plan has to approve certain services before you can get them. The process can delay care, deny treatments, and create paperwork headaches. Here is how it works and what to do when something gets denied.
What is prior authorization?
Prior authorization (also called pre-authorization or pre-cert) is when your insurance plan has to approve a service before you receive it. Without approval, the plan won't pay, and you could be stuck with the full bill.
Prior auth started as a way for plans to control costs and prevent unnecessary care. It now applies to a long list of services on most Medicare Advantage plans.
Does Original Medicare require prior authorization?
For most services, no. Original Medicare (Part A and Part B) does not require prior authorization for most doctor visits, hospital care, and outpatient procedures.
Original Medicare does require prior authorization for a few things:
- Power wheelchairs and certain mobility devices
- Some outpatient services in specific situations
- Inpatient psychiatric stays beyond 190 lifetime days
But the list is short compared to Medicare Advantage.
What about Medicare Advantage?
Almost all Medicare Advantage plans use prior authorization. The list of services that need approval varies by plan but commonly includes:
- MRIs and other advanced imaging
- CT scans
- Most surgeries
- Specialist visits (with HMO plans)
- Skilled nursing facility stays
- Home health care
- Durable medical equipment
- Mental health inpatient care
- Certain prescription drugs (handled separately under Part D)
Some Medicare Advantage plans require prior auth for 100 or more types of services. Some require it for very few. The plan's Evidence of Coverage lists every service that needs prior auth.
How prior authorization works
The basic process:
- Doctor recommends a service. Your doctor decides you need an MRI, surgery, or other service that requires prior auth.
- Doctor's office submits the request. They send the request to the plan along with medical records justifying the service.
- The plan reviews. Standard reviews take 14 days. Urgent reviews take 72 hours.
- The plan approves or denies. If approved, you can schedule the service. If denied, your doctor or you can appeal.
The 2024 federal rules
In 2024, the federal government created new rules to speed up Medicare Advantage prior authorization:
- Plans must respond to standard prior auth requests within 7 days (down from 14)
- Urgent requests must be answered in 72 hours
- Plans have to provide a specific reason for denial
- Approvals are valid for at least 90 days
These rules took full effect in 2026. They are a significant improvement, but plans still deny a lot of requests and the process can still be frustrating.
Common reasons for denial
Plans deny prior auth requests for several reasons. The most common:
- The service is not considered "medically necessary"
- The doctor did not provide enough documentation
- The plan wants you to try a cheaper option first (step therapy)
- The service is not covered under your plan
- The provider is out of network
- The documentation supports a different service than what was requested
The denial letter must tell you the specific reason. If it doesn't, that's grounds for an appeal.
How to appeal a prior authorization denial
You have the right to appeal any Medicare Advantage denial. There are five levels of appeal:
Level 1: Reconsideration by the plan
You file a request asking the plan to review the denial. The plan must respond within 30 days for standard requests, 72 hours for urgent.
How to file: Most plans accept appeals by phone, online, or by mail. The denial letter explains how. Include any new medical records or doctor's notes that support the service.
About 80 percent of appeals are won at this level when the patient or doctor provides additional documentation.
Level 2: Reconsideration by an Independent Review Entity (IRE)
If the plan upholds the denial, your case automatically goes to an independent reviewer who is not affiliated with the plan. The IRE reviews your case and decides.
Standard appeals: 30 days. Urgent: 72 hours. You don't have to do anything; the plan sends it to the IRE automatically if you ask.
Level 3: Administrative Law Judge hearing
If the IRE denies your appeal AND the amount in dispute is at least $190 in 2026, you can request a hearing with an Administrative Law Judge. This is similar to a courtroom hearing.
Level 4: Medicare Appeals Council
If the Administrative Law Judge denies, you can ask the Medicare Appeals Council to review the case.
Level 5: Federal District Court
If the amount is at least $1,900 in 2026, you can sue in federal court.
Most patients never go past Level 1 or 2. But the right to appeal is meaningful, and the appeals process actually works.
How to win an appeal
1. Get your doctor involved
The most important step. Your doctor knows the medical case and can write a strong appeal letter explaining why the service is medically necessary.
2. Provide medical records
Pull every relevant medical record, test result, and clinical note that supports the case. The more documentation, the better.
3. Cite Medicare coverage rules
If Medicare's coverage rules support your case, cite them. Medicare publishes National Coverage Determinations (NCDs) for many services. If an NCD supports coverage, the plan is required to follow it.
4. Use the right deadlines
You usually have 60 days from the denial to file an appeal. Don't miss this deadline.
5. Get help
State SHIP counselors help with Medicare Advantage appeals for free. The Center for Medicare Advocacy and Patient Advocate Foundation also help. See our Medicare resources guide.
Tactics that work
Request a peer-to-peer review
If your doctor asks, they can speak directly to a doctor at the plan to argue the case. This often gets denials reversed without a formal appeal.
Ask for fast-track appeals
If the service is urgent, request an expedited appeal. The plan has to decide in 72 hours instead of 30 days.
Document the impact of delay
If the denial is causing harm (pain, disease progression, mental anguish), document it. Adds urgency to your appeal.
Use Section 1801
This federal law says Medicare Advantage plans cannot cover less than Original Medicare for the same service. If Original Medicare would cover the service, the MA plan has to. This is a powerful argument in appeals.
How to avoid prior auth problems
Ask before scheduling
Before scheduling any non-routine service, ask the doctor's office if prior auth is required. Many denials happen because services were performed before authorization came through.
Read your plan's prior auth list
Your plan publishes a list of services that need prior auth. It's in the Evidence of Coverage or available from member services. Know what's on the list before you need it.
Choose a plan with less prior auth
Some plans require prior auth for almost everything. Others require it rarely. When picking a Medicare Advantage plan, ask about prior auth practices. Some carriers are known for being aggressive deniers, others are more lenient.
Consider Original Medicare plus Medigap
Original Medicare requires prior auth for very few services. If prior auth headaches are a deal-breaker, Original Medicare with a Medigap plan is the path with the least friction.
The bottom line
Prior authorization is here to stay on Medicare Advantage plans. The 2024 federal rules make the process faster and more transparent, but denials still happen. The most important thing to know: you have the right to appeal, and appeals frequently win.
If your prior auth gets denied, don't accept the first answer. Talk to your doctor, gather records, and file the appeal. Most denials get reversed when patients push back.
