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What to do when Medicare denies a claim

A denial is a decision you can challenge, and the letter that tells you about it also tells you how.

Last reviewed September 27, 2026

Is it a real denial, or a mistake the office can fix?

Often it’s a mistake. Call the billing office first and ask them to check the claim before you file anything.

Ask for an itemized statement, a list of every service they billed. Check the dates, the services and your Medicare number. If the office made a mistake, it can correct the claim, which is usually faster than an appeal. A call to the office doesn’t pause your appeal deadline, though.

Source: Medicare.gov, Medicare Appeals booklet, April 2026.

Why do Medicare claims get denied?

Most denials come down to one of a few reasons:

• Medicare decided the care wasn’t medically necessary. The notice may say the information sent “does not support the need” for the service. A letter from your doctor explaining why you needed it is the strongest reply.
• Medicare doesn’t cover the service at all. Routine dental care, hearing aids, routine eye exams and routine foot care are common examples. These are hard to win on appeal.
• A billing error. A wrong code, a wrong date or a missing detail.
• With Medicare Advantage: no prior approval, or an out-of-network provider. Many plans require approval before certain care. Prior authorization has its own guide: What is prior authorization in Medicare, and what to do if it's denied.

Appealing a plan denial can be worth it. In a 2022 review, federal inspectors found that 13% of the Medicare Advantage prior authorization denials they studied, and 18% of the payment denials, met Medicare’s coverage rules. Most of the wrongly denied payments came down to human or computer errors in processing.

Sources: Medicare.gov, Medicare Appeals booklet; HHS Office of Inspector General, OEI-09-18-00260.

How do you read the denial notice?

Look for three things: which service was denied, why, and the date your appeal has to arrive.

With Original Medicare, the notice is your Medicare Summary Notice, the statement Medicare mails at least every six months if you had care. It is not a bill.

• Page 1 answers “Did Medicare Approve All Services?” and shows how many were denied.
• The claims pages have a “Service Approved?” column. Look for “NO.” A letter in the “See Notes Below” column points to the reason at the bottom of the page.
• The “Maximum You May Be Billed” column shows the most the provider can charge you.
• The last page, “How to Handle Denied Claims or File an Appeal,” prints the exact date the appeal has to be received by and the address to send it to.

With Medicare Advantage, your plan sends an Explanation of Benefits, a statement that lists what it paid. When a plan turns down a request for care or payment, it must also send a written denial notice, usually called the “Notice of Denial of Medical Coverage (or Payment).” That notice gives the reason, the deadline and how to appeal. If you only have the Explanation of Benefits, call the plan and ask for the denial notice.

Sources: Medicare.gov, Medicare Summary Notice; Medicare.gov, sample Part B MSN; CMS, Medicare Advantage notices and forms; 42 CFR 422.111(k).

How do you appeal with Original Medicare?

There are five levels. You start at Level 1, and if you lose you can usually move up. Every decision letter explains how to take the next step.

1. Redetermination. The Medicare Administrative Contractor (the company that processes Medicare claims in your area) looks at the claim again. File within 120 days of getting your notice. Medicare assumes you got it five days after the date printed on it, and it counts the day your appeal arrives, not the day you mail it. You can circle the item on the notice and write why you disagree, or use form CMS-20027. The decision usually comes within 60 days. Each time you send more evidence, the contractor gets 14 more days.
2. Reconsideration. A Qualified Independent Contractor, a company that had no part in the first decision, reviews the case. File within 180 days of the Level 1 decision, using form CMS-20033 or a letter. The decision usually comes within 60 days. If it takes longer, you can ask to skip ahead to Level 3.
3. Hearing with a judge. An administrative law judge at the Office of Medicare Hearings and Appeals reviews the case, usually by phone or video. File within 60 days, using form OMHA-100. In 2026 the amount in dispute has to be at least $200. You can sometimes add claims together to reach it. The judge generally has 90 days to decide.
4. Medicare Appeals Council. File within 60 days, using form DAB-101. There’s no minimum dollar amount. The Council generally has 90 days to decide.
5. Federal district court. File within 60 days of the Council’s decision. In 2026 the amount in dispute has to be at least $1,960.

Missed the Level 1 deadline? Explain in writing why you were late, for example an illness. If the contractor agrees you had good cause, it can still accept the appeal.

Sources: Medicare.gov, appeals in Original Medicare; 42 CFR 405.942, 405.950, 405.962, 405.970, 405.1002, 405.1016, 405.1100, 405.1102; Federal Register, 2026 thresholds.

How do you appeal with a Medicare Advantage plan?

You start with your plan. If the plan says no again, an outside reviewer looks at the case automatically.

1. Plan reconsideration. Ask the plan to reconsider within 65 days of the date on the denial notice. Follow the instructions on the notice. Include your Medicare number, the service and dates, why you disagree, and anything from your doctor that helps. The plan has to decide within 30 days for care you haven’t had yet, 60 days for a bill for care you’ve already had, and 7 days for a Part B drug. For services it can sometimes take up to 14 more days, and it must tell you in writing if it does.
2. Independent Review Entity. If the plan upholds its denial, even partly, it must send your case to this outside organization, which works under contract with Medicare. You don’t need to file anything. The same 30-day, 60-day and 7-day limits apply.
3. The judge, then the Appeals Council, then federal court. Ask for a hearing within 60 days of the outside reviewer’s decision. From here the steps, the 60-day filing windows and the dollar minimums ($200 and $1,960 in 2026) are the same as in Original Medicare.

Sources: Medicare.gov, appeals in a Medicare health plan; 42 CFR 422.582, 422.590, 422.592, 422.600.

How do the two compare?

These minimums change every year. For appeals filed from January 1, 2027, the court minimum rises to $2,000. The hearing minimum stays at $200.

Sources: as above, and Federal Register, 2027 thresholds.

Can you get a faster decision?

Yes, if you’re waiting for care and the wait could harm your health. A fast appeal doesn’t apply to a bill for care you’ve already had.

With Medicare Advantage, you or your doctor can ask the plan for a fast appeal by phone or in writing. If your doctor says waiting could seriously harm your life, your health or your ability to recover, the plan must decide within 72 hours.

There is a separate fast appeal when a hospital says you’re ready to go home, or when skilled nursing, home health or hospice care is about to end. You call the Beneficiary and Family Centered Care Quality Improvement Organization, the independent reviewer named on your notice. For a hospital, call no later than your planned discharge day. For other care, call by noon the day before it’s due to stop. This works the same way in both types of Medicare.

Sources: 42 CFR 422.584, 422.590(e); Medicare.gov, fast appeals.

How can you appeal for a parent?

Your parent can name you as their representative. After that you can file and speak for them at every level.

Use the Appointment of Representative form, CMS-1696. You and your parent both sign and date it, and you send a copy with the appeal. It’s valid for one year from the day you both signed. Once it’s filed with an appeal, it covers that whole appeal. A signed letter also works if it includes the same details: both names, addresses and phone numbers, your relationship, permission to share health information with you, and what you’re helping with.

If you already have a health care power of attorney or a guardianship, you may be able to use that instead. Send a copy and ask the plan or contractor to confirm that it’s enough.

With Medicare Advantage, your parent’s doctor can also appeal a denial of care they haven’t had yet, without a form.

Sources: CMS, form CMS-1696; 42 CFR 405.910; 42 CFR 422.561; Medicare.gov, Medicare Appeals booklet.

What to ask, and in what order

1. Write the deadline on your calendar. Take it from the notice. Aim to send the appeal two weeks early.
2. Call the provider’s billing office. Ask: “Medicare denied this claim. Can you check whether it was billed correctly, and resubmit it if it wasn’t? Can you send me an itemized statement?”
3. If you’re not sure why it was denied, call 1-800-MEDICARE (1-800-633-4227) or the member services number on your plan card. Ask: “What rule or policy was this decision based on, and what would change it?”
4. Ask your doctor for a short letter. It should say what the care was, why you needed it, and what would happen without it. Include relevant records.
5. Send the appeal. Use the notice, the form, or a letter to the address on the notice. Put your Medicare number on every page. Keep a copy of everything, and use a way of sending that shows when it arrived.
6. Get free help if you need it. Your State Health Insurance Assistance Program gives free, one-to-one counseling, including help with appeals. Find yours at shiphelp.org.

Source: Medicare.gov, Medicare Appeals booklet.

Common questions

Is the Medicare Summary Notice a bill?
No. It shows what was billed and what Medicare paid. The bill comes from the provider. Check that it doesn’t charge more than the “Maximum You May Be Billed” amount on your notice.

Do I have to pay for something Medicare denied?
It depends. With Original Medicare, if your provider expected Medicare not to pay, they should have asked you to sign an Advance Beneficiary Notice before the care. If they were required to and didn’t, you generally don’t have to pay. Call 1-800-MEDICARE and ask about your case.

The amount is less than $200. Is it still worth appealing?
Yes. There’s no minimum for the first two levels. The $200 minimum starts at the hearing level.

My doctor’s office never sent the claim. Is it too late?
Providers have up to one year from the date of your care to send a claim to Original Medicare. Ask the office to file it.

Sources: Medicare.gov, Medicare Appeals booklet; CMS, Advance Beneficiary Notice.