How to File a Claim With Medicare

What happens when you file a Medicare claim

When you file a Medicare claim, you are telling Medicare about a medical service or item you received and asking them to pay their share of the cost. Most of the time, your doctor's office or hospital files the claim for you automatically — you do not have to do anything. But if a claim does not get filed, or if you want to check on one, you need to know how the process works and who to contact.

The basic flow is: your provider sends Medicare a record of what you received, Medicare reviews it against your coverage, Medicare pays the provider their share, and you get a bill for your share (your deductible, coinsurance, or copay). If something goes wrong at any step — a claim gets lost, Medicare denies it, or you think the amount is wrong — you have ways to find out what happened and push back.

Key Takeaways

Most providers file Medicare claims automatically, but you can check the status yourself using your Medicare account online or by calling 1-800-MEDICARE.
You will receive a document called an Explanation of Benefits (EOB) that shows what Medicare paid, what you owe, and why — keep these for your records.
If Medicare denies a claim or you disagree with the amount, you have the right to ask them to look at it again through a process called an appeal.
You can file a claim yourself if your provider does not, but you must do it within one year of receiving the service.

How to check if a claim was filed

The easiest way to see if a claim went through is to log into your Medicare account at Medicare.gov. Go to "Claims" in the left menu, and you will see a list of services Medicare has a record of. You can search by date, provider name, or type of service. The page will show you the date the claim was received, what Medicare paid, and what you owe.

If you do not have an online account, you can call 1-800-MEDICARE (1-800-633-4227) and speak to a representative. They can look up recent claims by your name and date of birth. Have your insurance card handy. The wait time is usually shorter early in the morning on weekdays.

If you received the service more than a few weeks ago and see no claim, contact your provider's billing office first. They may not have submitted it yet, or they may have submitted it to the wrong Medicare plan if you have Medicare Advantage instead of Original Medicare.

Understanding your Explanation of Benefits

After Medicare processes a claim, they send you a document called an Explanation of Benefits (EOB). This is not a bill — it is a record of what happened. The EOB shows the date of service, the provider's name, what service you received, what the provider charged, what Medicare decided to pay, and what you owe.

The EOB also explains why Medicare paid what they did. For example, it might say "You have not met your deductible" or "This service is covered at 80 percent after deductible." If Medicare denied the claim, the EOB will give you a reason code and an explanation. Keep your EOBs in a folder — you will need them if you want to appeal or if you have questions about a bill later.

If you have Medicare Advantage, your plan sends you an EOB instead of Medicare. The format may look different, but it contains the same information. If you do not receive an EOB within two weeks of a claim being processed, call your plan or Medicare to ask for one.

How to file a claim yourself

In most cases, your provider will file for you. But if they did not, you can file the claim yourself. You will need the original itemized bill from the provider — not just a receipt, but a detailed bill that shows the date of service, what was done, and the charge.

read the form CMS-1500 from Medicare.gov, or ask your provider to give you one. Fill in your information, your provider's information, and details about the service. You can also ask your provider's office to fill it out and give it to you to sign. Mail the completed form and the itemized bill to the Medicare claims address for your state. You can find the address on Medicare.gov or by calling 1-800-MEDICARE.

You must file within one year of the date you received the service. If you file after that, Medicare will deny the claim. Mail your claim with tracking so you have proof it arrived. Processing usually takes two to four weeks.

What to do if Medicare denies a claim

If Medicare denies your claim, the EOB will explain why. Common reasons include: the service is not covered under your plan, you have not met your deductible, the provider is out of network, or the service was deemed not medically necessary.

You have the right to ask Medicare to look at the denial again. This is called an appeal. You do not need a lawyer, and there is no cost. You have 120 days from the date on the EOB to file an appeal. Write a letter to Medicare explaining why you think the claim should be paid. Include a copy of the EOB, the itemized bill, and any medical records that support your case. Mail it to the address on the EOB.

If Medicare denies your appeal, you can ask for a second review, then a hearing before an independent reviewer. Each step has its own important date, which Medicare will tell you about. The Medicare website has a guide called "Your Medicare Appeal Rights and How to Use Them" that walks through the whole process.

If you think the amount Medicare paid is wrong

Sometimes Medicare pays less than you expected, or you disagree with what they say you owe. First, check the EOB to see what Medicare's reason was. If the provider charged more than Medicare's allowed amount, you should not have to pay the difference — that is the provider's responsibility.

If you think there is a math error, call 1-800-MEDICARE and ask them to review the calculation. Have your EOB in front of you. If you think the service should have been covered but was not, you can appeal using the same process described above.

If your provider is billing you for more than your copay, coinsurance, or deductible, contact your provider's billing office and ask them to explain the charge. If they cannot justify it, ask them to adjust the bill. You can also file a complaint with your state's insurance commissioner if you believe the provider is billing you incorrectly.

Keeping track of your claims

Create a straightforward system to organize your medical paperwork. Keep a folder for each year and put all EOBs, itemized bills, and receipts inside. Write the date and provider name on each document so you can find things quickly.

You can also keep a spreadsheet with the date of service, provider name, what was done, what Medicare paid, and what you owe. This makes it straightforward to spot patterns — for example, if you notice Medicare is denying claims from one provider repeatedly, you can investigate why.

Check your Medicare account online once a month to see if new claims have been processed. This way, you catch problems early instead of discovering them months later when you get a surprise bill.

Frequently Asked Questions

Do I have to pay the provider before Medicare pays them?

No. Your provider bills Medicare first. Medicare pays their share directly to the provider. You only pay your share (copay, coinsurance, or deductible) after Medicare has paid. If a provider asks you to pay the full amount upfront, ask them to bill Medicare first and then send you a bill for what you owe.

What if my provider says they will not file a Medicare claim?

Medicare requires providers who treat Medicare patients to file claims on your behalf. If a provider refuses, you can file the claim yourself using the CMS-1500 form, or you can report the provider to Medicare by calling 1-800-MEDICARE. You should not have to pay out of pocket for a covered service just because the provider will not file.

How long does it take Medicare to process a claim?

Most claims are processed within two to four weeks. You can check the status online or by calling 1-800-MEDICARE. If it has been more than a month and you see no record of the claim, contact your provider to confirm they filed it.

Can I appeal a claim denial if I already paid the bill?

Yes. You can appeal even after you have paid. If you win the appeal, Medicare will pay you back. You have 120 days from the date on the EOB to file, so do not wait too long.

What if I have both Original Medicare and a Medigap plan?

Medicare processes the claim first and pays their share. Then your Medigap plan automatically receives the EOB and pays their share of what you owe. You should not have to file anything with your Medigap plan — it happens automatically. If you do not see a payment from your Medigap plan within a few weeks, call them to check the status.

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.