Where to Mail Your Medicare Part B Claims and How to Submit Them

The mailing address depends on which plan you have and what you're sending

Medicare Part B claims go to different addresses depending on whether you have Original Medicare or a Medicare Advantage plan, and whether you're submitting a paper claim yourself or your provider is doing it. If you have Original Medicare and your doctor hasn't already sent the claim to Medicare, you'll mail it to a regional Medicare contractor — not to a single national address. The contractor for your state is listed on your Medicare card and on the Medicare website by ZIP code.

Most claims are now submitted electronically by providers, so you may never need to mail anything. But if you do need to send a paper claim — because a provider didn't submit it, or because you paid out of pocket and want reimbursement — the address matters, and using the wrong one delays processing.

Key Takeaways

Original Medicare claims go to your regional Medicare contractor, whose address appears on your Medicare card and varies by state and ZIP code.
Medicare Advantage plan claims go to your plan's claims address, which is in your plan materials and on your plan's website, not to Medicare directly.
You can find your correct mailing address by calling 1-800-MEDICARE, checking your Medicare card, or visiting Medicare.gov and entering your ZIP code.
Most providers submit claims electronically now, so paper claims are uncommon unless you paid out of pocket or a provider failed to submit.
Include your Medicare number, date of service, provider name, and itemized charges on any paper claim you mail.

How to find your regional Medicare contractor's address

Your Medicare card lists your regional Medicare contractor in small print, usually on the back. The contractor processes all Original Medicare Part B claims in your state or region. To find the exact mailing address, you have three options: call 1-800-MEDICARE and ask for your contractor's address, visit Medicare.gov and use the "Find Care Providers" tool to enter your ZIP code, or look at the back of your Medicare card where the contractor name appears.

The contractor name and address do not change often, but they can shift if Medicare reorganizes contracts. If you have an old address, calling 1-800-MEDICARE takes two minutes and ensures you're using the current one. The phone line is open Monday through Friday, 8 a.m. to 8 p.m. Eastern time.

What to include when you mail a Part B claim

A paper Part B claim must include your Medicare number, the date of service, the provider's name and address, a description of the service, the amount you paid, and proof of payment if you paid out of pocket. Medicare uses the CMS-1500 form for paper claims, though some providers may accept a straightforward letter with this information.

Keep a copy of everything you mail. Include a cover letter stating why you're submitting the claim — for example, "I paid this bill out of pocket on [date] and am requesting reimbursement" or "My provider did not submit this claim and I received a bill." Write your Medicare number on every page. Mail it certified mail with return receipt so you have proof it arrived.

Medicare Advantage plan claims go to your plan, not Medicare

If you have a Medicare Advantage plan (Part C), you do not send claims to Medicare. You send them to your plan's claims address, which is listed in your plan's member handbook and on your plan's website. Each plan has its own claims process and mailing address. Your plan's customer service number is on your insurance card.

Most Medicare Advantage plans also accept electronic submission through their member portal or by fax. Before you mail a paper claim, call your plan to ask whether they prefer mail, fax, or online submission. Fax or online submission is usually faster.

When you should submit a paper claim yourself

You normally do not need to submit a claim. Your doctor's office or hospital submits it electronically to Medicare within days of your visit. You receive an Explanation of Benefits (EOB) in the mail showing what Medicare paid and what you owe.

You should submit a paper claim yourself only if: your provider tells you they did not submit it and will not, you paid the full bill out of pocket and want reimbursement, or you received a bill from a provider and Medicare says they have no record of the claim. In these cases, gather your receipts and the provider's itemized bill, then mail them with a cover letter to your regional contractor.

What happens after you mail your claim

Medicare contractors typically process paper claims within two to four weeks, though it can take longer if information is missing. You'll receive an EOB in the mail showing whether Medicare approved the claim, how much they paid the provider or you, and what you owe. If the claim is denied, the EOB explains why and tells you how to appeal.

If you don't receive an EOB within six weeks, call 1-800-MEDICARE and provide your Medicare number and the date you mailed the claim. They can look up the claim status and tell you whether it was received and processed.

Electronic submission and online portals

Many providers now offer online claim submission through patient portals or find email. If your provider's office has a patient portal, you can often upload receipts and request reimbursement directly through it. This is faster than mailing and gives you a record of submission when ready.

Some providers also accept fax claims. If you choose to fax instead of mail, use the fax number listed on your provider's bill or website, not a general Medicare fax line. Keep a fax confirmation sheet as proof of transmission.

Frequently Asked Questions

Can I submit a Part B claim online instead of mailing it?

Most providers submit claims electronically, so you won't need to. If you need to submit one yourself, some providers accept online submission through a patient portal or find email. Call your provider's billing department to ask. If they don't offer online submission, mailing or faxing are your options.

What if I mail my claim to the wrong address?

If you mail it to the wrong regional contractor, it will likely be forwarded to the correct one, but it may take longer. To avoid delay, verify your contractor's address before mailing. If you've already mailed it and are unsure, call 1-800-MEDICARE with your Medicare number and claim details so they can track it down.

How long does Medicare take to process a paper claim?

Most paper claims are processed within two to four weeks. Complex claims or claims with missing information can take longer. You'll receive an Explanation of Benefits in the mail. If you don't hear back within six weeks, contact 1-800-MEDICARE to check the status.

Do I need to mail the original receipt or can I send a copy?

Send a copy, not the original. Keep the original for your records. Make sure the copy is clear and shows the date of service, provider name, service description, and amount charged. If you paid out of pocket, include proof of payment such as a cancelled check or credit card statement.

What's the difference between mailing a claim and filing an appeal?

A claim is your initial request for Medicare to pay for a service. An appeal is a request to reconsider if Medicare denies the claim. Appeals have different forms and important date and go to a different address. Your Explanation of Benefits will tell you which process applies and where to send your paperwork.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.