How Healthcare Providers Bill Medicare for Your Care

What happens when you see a Medicare-covered provider

When you visit a doctor, hospital, or other healthcare provider who accepts Medicare, that provider submits a bill to Medicare on your behalf. The provider sends a claim form that lists the services you received, the date, and the cost. Medicare reviews the claim, decides what it will pay based on your coverage type and the service itself, and sends payment directly to the provider. You receive an explanation of benefits (EOB) in the mail that shows what Medicare paid and what you owe.

The process is largely automatic — you do not have to do anything to start it. Your provider has your Medicare number from your insurance card, and they use that to file the claim. However, understanding how the billing works helps you catch errors, know what bills are legitimate, and understand what you actually owe.

Key Takeaways

Your provider submits the claim to Medicare using your Medicare number; you do not file it yourself.
Medicare sends you an Explanation of Benefits (EOB) showing what it paid, what you owe, and the provider's charges.
You are responsible for your deductible, coinsurance, and copayments — amounts that vary by service and your coverage type.
If a provider bills you for the full amount before Medicare processes the claim, ask them to wait for Medicare's decision.
Providers who do not accept Medicare assignment can bill you for the difference between their charge and what Medicare allows.

The claim form and what information goes on it

Your provider uses a standard form called the CMS-1500 (for doctors and other individual providers) or the UB-04 (for hospitals and facilities). These forms contain your name, Medicare number, date of birth, the dates of service, diagnosis codes, procedure codes, and the amount charged for each service.

The provider's billing office enters this information and sends it electronically to Medicare's regional contractor. That contractor is a private company that Medicare hires to process claims in your state. The contractor checks that the claim is complete, that the service is covered under your plan, and that the charge falls within Medicare's allowed amount for that service in your area.

How Medicare decides what to pay

Medicare has a fee schedule for each type of service — an amount it considers reasonable for that service in your geographic area. If your doctor charges $200 for an office visit but Medicare's allowed amount is $120, Medicare bases its payment on $120, not $200.

For Original Medicare (Part A and Part B), Medicare typically pays 80 percent of the allowed amount after you meet your deductible. You pay the remaining 20 percent, called coinsurance. For hospital stays covered under Part A, you pay a deductible per benefit period, then Medicare covers all approved costs for the first 60 days. Hospital stays longer than 60 days involve daily copayments that increase the longer you stay.

If you have a Medicare Advantage plan (Part C) or a Medigap policy, the payment split is different. Your plan documents spell out your specific copayments and coinsurance amounts. When you see a provider, that provider bills your Medicare Advantage plan or your Medigap insurer, not Original Medicare directly.

What you will see on your Explanation of Benefits

After Medicare processes the claim, it mails you an EOB. This document shows the provider's name, the date of service, the service code and description, the amount the provider charged, the allowed amount Medicare recognizes, what Medicare paid, and what you owe. The EOB also notes whether the provider is contracted with Medicare (accepts assignment) or not.

The EOB is not a bill — it is a record of what happened. Your actual bill comes from the provider, and it should match the "you owe" amount on the EOB. If the provider bills you for more than that amount, contact the provider's billing office and ask them to correct it. If they do not, you can file a complaint with your state's insurance commissioner or with Medicare directly.

Keep your EOBs. They are proof of what Medicare paid and what you owe. If you receive a bill you do not recognize, compare it to the EOB to see whether the service was actually covered and what the allowed amount was.

Assignment and non-assignment: what it means for your bill

A provider who accepts assignment agrees to take Medicare's allowed amount as full payment for the service (minus your deductible, coinsurance, or copayment). They cannot bill you for the difference between their charge and what Medicare allows. This is the standard arrangement for most doctors and hospitals.

A provider who does not accept assignment can bill you for the difference. If Medicare's allowed amount is $120 and the provider charged $200, you could owe the 20 percent coinsurance ($24) plus the $80 difference — a total of $104. This is called balance billing, and it can happen with some specialists, therapists, and out-of-network providers.

Before you see a provider, ask whether they accept Medicare assignment. Your Medicare card lists whether you have Original Medicare or a Medicare Advantage plan. If you have Original Medicare, you can search the Medicare provider directory online to check assignment status. If you have a Medicare Advantage plan, call your plan to confirm the provider is in-network and what your copayment will be.

When you receive a bill before Medicare processes the claim

Providers sometimes send you a bill before Medicare has made its decision. This is normal — the provider's billing office may send a statement to keep you informed. However, you should not pay it until you see the EOB from Medicare. Once you have the EOB, you will know exactly what you owe.

If a provider demands payment before Medicare processes the claim, ask them in writing to hold the bill pending Medicare's decision. Keep a copy of your request. Providers are required to wait a reasonable time for Medicare to process before they can pursue collection. If a provider continues to pressure you, contact Medicare's beneficiary hotline at 1-800-MEDICARE to report it.

Errors on your bill and how to dispute them

Billing errors happen. A service might be coded incorrectly, billed twice, or listed as not covered when it should be. If you notice a discrepancy between your EOB and your bill, or if you believe a service should not have been billed to you, contact the provider's billing office first. Ask them to explain the charge and provide a copy of the claim they submitted to Medicare.

If the provider cannot resolve it, you can file an appeal with Medicare. The process depends on whether you have Original Medicare or a Medicare Advantage plan. For Original Medicare, you can request a redetermination by calling the phone number on your EOB. For Medicare Advantage, contact your plan's appeals department. Medicare has specific timelines for appeals — usually 60 days from the date on your EOB to request one.

Frequently Asked Questions

Do I have to do anything to get Medicare to pay my doctor?

No. Your provider submits the claim using your Medicare number from your insurance card. You do not file anything. Your only job is to provide your Medicare number when you check in and to pay your copayment or coinsurance at the time of service if the provider asks for it.

What if my doctor charges more than Medicare allows?

If your doctor accepts assignment, they cannot charge you more than Medicare's allowed amount plus your deductible and coinsurance. If they do not accept assignment, they can bill you for the difference. Before your visit, ask whether the provider accepts assignment. If they do not, ask what the total out-of-pocket cost will be.

How long does it take Medicare to process a claim?

Most claims are processed within two to four weeks. You should receive your EOB in the mail within that timeframe. If you do not receive an EOB after a month, contact the provider's billing office to confirm they submitted the claim, then call Medicare at 1-800-MEDICARE if the claim was submitted but you still have not received an EOB.

Can I see my claim status online?

Yes. If you have a Medicare.gov account, you can log in and view your claims under "Claims and Appeals." You can see what was billed, what Medicare paid, and what you owe. This is faster than waiting for the paper EOB to arrive in the mail.

What should I do if I receive a bill I do not think I owe?

Compare the bill to your EOB. If the service is listed on the EOB and Medicare paid its share, you owe only your coinsurance or copayment. If the service is not on the EOB, contact the provider and ask them to explain why it was billed. If they cannot provide a clear answer, file a complaint with Medicare or your state insurance commissioner.

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.