Medicare reimbursement is the money Medicare sends to doctors, hospitals, and other providers after you receive care

When you go to the doctor or hospital, Medicare doesn't pay you directly. Instead, the provider submits a claim to Medicare, and Medicare pays them a set amount for that service. That payment is called reimbursement. The amount varies depending on the type of care, where you live, and which Medicare program you're in — Original Medicare, a Medicare Advantage plan, or a Medigap policy.

Understanding how reimbursement works helps you know what you might owe out of pocket. If a provider is paid less by Medicare than they charge, you may be responsible for the difference — unless you have Medigap coverage or are in a Medicare Advantage plan with network protections.

Key Takeaways

  • Medicare reimbursement is the payment Medicare sends to your provider after you receive care, not a payment to you.
  • Original Medicare sets fixed reimbursement rates based on a fee schedule; Medicare Advantage plans set their own rates and may reimburse differently.
  • Providers who accept Medicare assignment agree to accept Medicare's reimbursement as full payment and cannot bill you for the difference.
  • If a provider does not accept assignment, you may owe the difference between what Medicare pays and what the provider charges.
  • Your out-of-pocket costs depend on deductibles, copays, and coinsurance — not directly on what Medicare reimburses the provider.

How Original Medicare sets reimbursement amounts

Original Medicare uses a system called the Medicare Physician Fee Schedule to decide how much to pay doctors. This schedule lists thousands of medical procedures and services, and each one has a set payment amount. The amount is based on how complex the service is, how much time it takes, and what it costs to provide it in your region.

Hospitals are paid differently. Medicare uses a system called Diagnosis-Related Groups (DRGs) for inpatient hospital stays. Instead of paying for each test or procedure separately, Medicare pays a flat rate based on your diagnosis. For example, if you are admitted for pneumonia, the hospital receives one payment for the entire stay, regardless of how many X-rays or medications you receive.

These rates are set by Congress and updated each year. They do not change based on how much a hospital or doctor charges privately — Medicare pays what Medicare decides, and that is final.

What happens when a provider accepts or does not accept assignment

Assignment means a provider agrees to accept Medicare's reimbursement as full payment. When a doctor or hospital accepts assignment, they cannot bill you for any difference between what they charge and what Medicare pays. You pay only your deductible, copay, or coinsurance — the amounts Medicare says you owe.

If a provider does not accept assignment, they can bill you for the difference. For example, if a doctor charges $200 for a visit and Medicare reimburses $120, a non-participating provider can ask you to pay the full $200 and then bill Medicare for $120. You would owe the $80 difference. This is called balance billing.

Most doctors and hospitals accept assignment because it is simpler and they reach more patients. You can ask your provider before your visit whether they accept Medicare assignment. The Medicare website has a searchable directory of participating providers in your area.

How Medicare Advantage plans handle reimbursement differently

If you are in a Medicare Advantage plan, the plan itself receives a fixed payment from Medicare for your care. The plan then decides how much to reimburse its network providers. This means reimbursement rates can vary from plan to plan and may be different from Original Medicare rates.

Medicare Advantage plans must cover all the same services as Original Medicare, but they set their own payment amounts to providers. Some plans pay more than Original Medicare; others pay less. Providers in the plan's network agree to accept the plan's reimbursement rates, so you are protected from balance billing as long as you use in-network providers.

If you see an out-of-network provider in a Medicare Advantage plan, reimbursement rules change. The plan may pay less, and you may owe more. Some plans do not cover out-of-network care at all except in emergencies.

The difference between reimbursement and what you pay

It is straightforward to confuse what Medicare reimburses the provider with what you owe. They are not the same. Your out-of-pocket cost is determined by your deductible, copay, and coinsurance — not by how much Medicare reimburses.

For example, suppose Medicare reimburses a doctor $100 for an office visit. If your copay is $20, you pay $20 and Medicare pays $80. The total reimbursement to the doctor is $100. If your copay were $30, you would pay $30 and Medicare would pay $70 — but the total reimbursement to the doctor stays $100.

Your deductible works the same way. If you have not met your deductible, you pay the full cost of the service (up to the deductible amount) and Medicare pays nothing. Once you meet the deductible, Medicare begins to reimburse, and you pay only your copay or coinsurance.

Why some providers refuse Medicare patients

Some doctors and hospitals do not accept Medicare at all. They may decide that Medicare's reimbursement rates are too low to cover their costs, or they may prefer to work only with private insurance. If a provider does not accept Medicare, you cannot use your Medicare coverage there — you would have to pay out of pocket or find a different provider.

This is different from not accepting assignment. A provider who accepts Medicare but does not accept assignment will still file a claim with Medicare and receive reimbursement; they just may bill you for the difference. A provider who does not accept Medicare at all will not file a claim and will ask you to pay the full amount upfront.

If you need a specialist or procedure and your regular provider does not accept Medicare, ask for a referral to someone who does. Your primary care doctor usually knows which specialists in your area accept Medicare.

How to find out what Medicare will reimburse for a specific service

You can look up Medicare reimbursement rates before you have a procedure. The Medicare Physician Fee Schedule Look-Up Tool on the Centers for Medicare & Medicaid Services (CMS) website lets you search by procedure code or service name. You enter your state and the code, and it shows you the reimbursement amount for your region.

Keep in mind that this tool shows what Medicare will pay the provider, not what you will pay. Your cost depends on your deductible status and your copay or coinsurance. If you want to know your exact out-of-pocket cost before a procedure, call your doctor's office and ask them to estimate it based on your plan.

For hospital stays, reimbursement is harder to predict because it depends on your diagnosis and how long you stay. If you are scheduled for inpatient surgery, ask the hospital's billing department for an estimate. They can tell you what your copay or coinsurance will be, even if they cannot predict the exact length of stay.

Frequently Asked Questions

Does Medicare reimbursement affect how much I pay?

Not directly. Your out-of-pocket cost is set by your deductible, copay, and coinsurance — not by what Medicare reimburses the provider. However, if a provider does not accept assignment, they can bill you for the difference between what they charge and what Medicare pays, which increases your cost.

What if my doctor charges more than Medicare reimburses?

If your doctor accepts assignment, they cannot charge you the difference. If they do not accept assignment, they can bill you for it. Always ask whether your provider accepts Medicare assignment before your visit to avoid surprise bills.

Can I appeal if I think Medicare reimbursed my provider too much?

You cannot appeal Medicare's reimbursement decision to the provider. If you believe Medicare paid incorrectly, you can file an appeal with Medicare directly. Your provider can also appeal if they think they were underpaid, but that does not affect your bill.

Do Medicare Advantage plans reimburse providers the same way as Original Medicare?

No. Medicare Advantage plans set their own reimbursement rates, which may be higher or lower than Original Medicare. Rates vary by plan and region. Providers in the plan's network agree to accept these rates, so you are protected from balance billing.

How do I know if my provider accepts Medicare assignment?

Call your provider's office and ask directly, or search the Medicare Provider Enrollment, Chain, and Ownership System (PECOS) on the CMS website. You can also ask at your appointment. Providers who accept assignment will tell you upfront.