Medicare Prior Authorization Phone Number Tips
Call 1-800-MEDICARE (1-800-633-4227) first, then use your specific Medicare plan's number for prior authorization requests (Part C/Medicare Advantage and Part D are handled by the insurer, not a single national "prior auth" line).
Medicare prior authorization phone numbers
Because "prior authorization" is implemented through Medicare's plan structures, the right phone number depends on which coverage you're using-Original Medicare versus a Medicare Advantage plan (Part C).
- Original Medicare (Parts A & B): Use 1-800-MEDICARE to route your question to the right area for your situation.
- Medicare Advantage (Part C): Call your plan/insurer's Utilization Management (UM) line for prior authorization and status.
- Prescription coverage (Part D): Call the prescription plan number on your card; prior authorization processes are handled by the insurer.
| Coverage Type | Where to Call | Phone Number (Example) | Best For |
|---|---|---|---|
| Original Medicare (Parts A/B) | Medicare national line | 1-800-MEDICARE (1-800-633-4227) | Routing help and general Medicare guidance |
| Medicare Advantage (Part C) | Insurer UM / preauth desk | Example: 855-339-8127 | Pre-service prior authorization and status checks |
| Medicare Advantage (Part C) | After-hours UM (example) | Example: 313-236-7836 | Urgent inquiries when the main line is closed |
| Part D | Your prescription plan | Use the number on your plan card | Drug prior authorization and coverage questions |
How to get the correct number
Most callers waste time by guessing a "universal" prior authorization line, but Medicare routes prior authorization differently depending on whether the request is administered by Medicare itself or by your private plan.
- Identify your coverage: Original Medicare (A/B) or Medicare Advantage (Part C) or Part D drug coverage.
- If you're not sure, call 1-800-MEDICARE for routing guidance.
- If you have Medicare Advantage or Part D, call the insurer number for utilization management/prior authorization-often printed on your insurance card.
"If you're calling for a pre-service request, ask explicitly for the Utilization Management or prior authorization department so you don't get sent to general billing or claims."
What to say when you call
When you contact the prior authorization desk, clarity reduces back-and-forth; have the basics ready (patient identifier, service details, and the ordering clinician).
- State the request type: "prior authorization for a service / procedure / medication."
- Give timing: "pre-service" versus "urgent" versus "post-service review."
- Ask for status: "Is there a case number or reference ID for this prior authorization?"
Quick tips before you call
Plan-based prior authorization workflows frequently involve specific departments and time windows, so confirming the correct department (not just the correct organization) is the fastest path to resolution.
- Call during plan business hours when possible for faster handling.
- If the service is time-sensitive, ask whether there's an expedited process (your insurer will advise the applicable pathway).
- If you can't reach a representative, ask for the best alternate contact method for prior authorization requests.
Marist Education Authority note
At a leadership level, we treat "access to care" like a school support pathway: when stakeholders (families, providers, and administrators) have the right communication channel and the correct terms, outcomes improve and delays decrease-especially in urgent situations.
In practical terms, if your staff or families are supporting beneficiaries, we recommend maintaining a single internal sheet that records the correct phone line per plan type and the patient's key details, because "one number for everyone" is rarely accurate.
Strict FAQ
Helpful tips and tricks for Medicare Prior Authorization Phone Number Tips
What is the Medicare prior authorization phone number?
Start with 1-800-MEDICARE (1-800-633-4227) to get routed correctly, then contact your specific Medicare plan (insurer) for prior authorization if you have Medicare Advantage or Part D.
Is there one universal prior auth number for Medicare?
No-prior authorization is administered through your coverage structure, so Medicare routing differs between Original Medicare and plan-administered coverage like Medicare Advantage and Part D.
What number should I call for Medicare Advantage prior authorization?
Call your Medicare Advantage plan's Utilization Management (UM) department, using the phone number on your plan materials or card; some examples include insurer UM lines such as 855-339-8127.
What if I need help after hours?
If your plan provides an after-hours UM line, use that number-some plans publish examples of after-hours UM contact numbers separate from main business-hours lines.
Do I call the same number for Part D drug prior authorization?
Typically, you call your prescription drug plan (Part D) using the plan's contact number, because drug prior authorization is handled by the insurer.
