Medicare Fax Number: Find the Right One for Your Task

Searching for "the Medicare fax number" usually turns up one number copied across many sites. Medicare doesn't work that way. The right fax depends on what you're sending, which part of Medicare it's for, and sometimes which state you live in.

Every fax number on this page was checked on official CMS, Medicare.gov or Medicare contractor pages on 10 October 2026. Where a number depends on your region or plan, we link to the official lookup instead of guessing. For other agencies, see the government fax numbers hub.

Which Medicare office do you need?

If you're unsure, read the notice you're responding to. Every Medicare decision letter says where the next step goes.

Level 1: Redetermination by your Medicare contractor

The first appeal of an Original Medicare claim is a redetermination. A Medicare Administrative Contractor (MAC) handles it. Several MACs share the country by region, and some states have different contractors for medical claims, home health and hospice, and durable medical equipment.

Start with your Medicare Summary Notice. Medicare.gov's appeal guide says to file by the deadline on the MSN, and to send your request to the contractor address on its last page. You can use the Redetermination Request Form linked there, or a written request.

Many MACs publish a fax for redeterminations, but the numbers differ by jurisdiction and claim type, and they change when contracts move. We don't list them here. To find yours:

1. Note the contractor name on your MSN.
2. Look up that contractor on CMS's Who are the MACs page, which links each jurisdiction to its MAC.
3. On the MAC's own website, open its appeals or redetermination page and use the fax listed for your claim type.

If you can't find a fax, mail the request to the address on your MSN. A wrong fax number can be a privacy problem and won't stop your deadline.

Level 2: Reconsideration by a Qualified Independent Contractor

If the MAC still denies the claim, the next step is a reconsideration by a Qualified Independent Contractor (QIC). You have 180 days from receiving the redetermination decision. Your notice names the QIC to use. You can use form CMS-20033 or a written request, and attach a copy of the notice.

CMS lists these fax numbers for standard reconsideration requests. Each one also appears on the contractor's own website:

The state lists for Part A West are on Maximus's Part A West page. For the other regions, rely on the QIC named in your notice rather than guessing from a map.

Fast (expedited) reconsiderations are different. They follow a quality improvement organization decision about a discharge or services ending, and timing is tight: usually noon the day after you're told. In Part A West, Maximus takes them by phone at 1-866-950-6509 or by fax at 585-869-3365. In Part A East, C2C takes them by phone at 1-855-371-5817.

Medicare Advantage plans

Medicare Advantage plans run their own appeals. Medicare.gov says to follow the directions in your plan's denial notice, and to file within 65 days of that notice. Use the fax number the plan gives in that notice or its member materials.

If the plan upholds its denial, it automatically forwards the case to an independent review entity. You don't need to fax anything for that second level.

Part D drug plans

For a prescription drug denial, appeal to your drug plan first, using the fax in its letter. If the plan rules against you again, you can ask the Part D independent review entity, C2C Innovative Solutions, to review it. File within 65 days of the plan's decision.

C2C publishes these fax numbers for enrollees and their representatives:

Send one request per submission. C2C asks you not to fax a request you already sent through its portal, because duplicates can slow processing.

Other Medicare tasks people fax

• Discharge and "services ending" appeals. Contact your Beneficiary and Family Centered Care QIO, either Acentra Health or Commence Health. The number depends on your state. Use the notice from your provider or CMS's BFCC-QIO page, and call first, since these are time-sensitive.
• Part B enrollment. CMS says you can submit Form CMS-40B by mail, by fax or in person at your local Social Security office. If you're enrolling through a Special Enrollment Period, CMS-L564 and proof of coverage go with it. See our Social Security fax guide for finding your office's number.
• Other insurance that pays first (coordination of benefits). CMS's Benefits Coordination & Recovery Center lists fax 1-833-844-1427 for Data Collections correspondence. If you received a recovery letter, use the return address or fax on that letter instead, as CMS's contacts page instructs.

What to include in your fax

Medicare.gov and CMS list similar items for appeals:

• Your name, address and Medicare Number from your card
• The items or services and dates of service you're appealing
• Why you disagree with the decision
• A copy of the notice you're appealing (MSN, redetermination notice or plan letter)
• The name of the contractor or plan that made the decision
• An Appointment of Representative form if someone is filing for you
• Supporting records, such as a letter from your doctor

Put the appeal form or request letter first, then the notice, then the evidence. Write your name and Medicare Number on every page in case pages get separated.

Medical records and HIPAA

Appeals often include medical records. Send only what the request needs, and double-check the number against your notice or the official page before you send.

A HIPAA fax cover sheet helps the recipient route the pages and flags them as confidential. A cover sheet is not enough on its own. It doesn't fix a wrong number or replace the safeguards a covered entity needs.

If you're a clinic, billing service or other covered entity sending patient records, use HIPAA Secure with an active organization business associate agreement. See our compliance overview for details. A patient faxing their own appeal can use ordinary sending. For general steps, see how to fax medical records to a doctor or clinic.

How to send your Medicare fax for $0.99

You don't need a fax machine or an account.

1. Scan or photograph your pages as one PDF, in the order above.
2. Open the SingleFax send page and enter the fax number from your notice or the official page.
3. Add a cover page if you want one. Our free fax cover sheet generator works too.
4. Check the preview, then pay. $0.99 covers up to 10 pages, about $0.08 per extra page, and you pay only if the fax is delivered.
5. Keep the confirmation with your copy of the appeal. It shows the fax went through, not that the appeal was decided.

For a prior authorization or other plan form, our CVS Caremark fax guide shows a similar workflow.

Have the number from your notice? Send your fax now.