Medicare pays providers through a system of set rates, not negotiated prices

Medicare does not pay what a doctor or hospital charges. Instead, the Centers for Medicare & Medicaid Services (CMS) sets a fixed payment amount for each service — a doctor visit, a surgery, a lab test, an X-ray. The provider either accepts that amount or does not participate in Medicare. You do not negotiate the price; the rate is the same whether you are the patient or not.

This matters because it affects what you pay out of pocket. If your doctor accepts Medicare's rate, your cost is limited to your deductible, copay, or coinsurance. If your doctor does not accept Medicare, you may owe the full bill — unless your doctor is "opted out," which is a different status with its own rules.

The payment system works differently depending on the type of provider and the type of service. A hospital gets paid one way for an inpatient stay, another way for an outpatient procedure. A doctor in a group practice may be paid differently than a solo practitioner. Understanding which system applies to your care helps you predict what Medicare will cover and what you will owe.

Key Takeaways

  • Medicare sets fixed payment rates for each service; providers cannot charge more if they accept Medicare.
  • Doctors who accept Medicare are called "participating providers," and your out-of-pocket cost is capped at your deductible and coinsurance.
  • Hospitals are paid a flat rate per hospital stay based on your diagnosis, not on how many tests or days you spend there.
  • Doctors who opt out of Medicare can charge whatever they want, but they must sign a contract with you before treatment and cannot bill Medicare at all.
  • Payment happens directly from Medicare to the provider; you typically do not pay the provider and then seek reimbursement.

How Medicare pays doctors and other outpatient providers

Most doctors, specialists, and outpatient clinics are paid through the Medicare Physician Fee Schedule, a list of about 10,000 services with a set payment for each one. The payment is called the "allowed amount." If your doctor accepts Medicare, they bill Medicare for the allowed amount, and Medicare pays them a percentage (usually 80 percent after you meet your deductible). You pay the rest — your coinsurance, usually 20 percent.

The allowed amount varies by location. A cardiologist visit in New York City has a different allowed amount than the same visit in rural Kansas. The variation reflects differences in the cost of living and practice expenses, though the exact formula is complex and changes year to year.

If your doctor does not accept Medicare but has not formally opted out, they can still bill you for the difference between their charge and Medicare's allowed amount. This is called "balance billing," and it can be substantial. A doctor who accepts Medicare cannot balance bill you. This is why it matters whether your doctor is a participating provider — you can check on Medicare.gov's "Care Provider Search" tool.

How Medicare pays hospitals for inpatient stays

Hospitals are paid very differently from doctors. Instead of a fee for each service, Medicare pays hospitals a flat rate based on your diagnosis. This system is called Diagnosis-Related Group (DRG) payment. The hospital receives one payment for your entire stay, whether you are there for two days or ten days, whether you have one test or twenty.

The DRG rate is set by CMS and varies by hospital location and teaching status (teaching hospitals receive higher payments). The hospital keeps any money left over if your care costs less than the DRG rate, and absorbs the loss if your care costs more. This creates an incentive for hospitals to manage costs efficiently.

Your cost as a patient is your inpatient deductible (which resets each year) plus coinsurance for days beyond a certain threshold. The hospital bills Medicare directly; you do not pay the hospital upfront and seek reimbursement. If the hospital is out of network or you receive care from an out-of-network doctor while you are in a network hospital, your costs may be higher.

How Medicare pays for outpatient hospital services

When you receive care at a hospital outpatient department — such as an imaging center, emergency room, or same-day surgery center — the payment method is different again. These services are paid under the Outpatient Prospective Payment System (OPPS). Like the DRG system, OPPS pays a flat rate per service category, not per individual test or procedure.

Outpatient hospital services typically cost you more than the same service at a doctor's office, even though Medicare's allowed amount is higher. This is because hospital outpatient departments have higher overhead costs, and Medicare's payment reflects that. Your coinsurance is usually 20 percent of the allowed amount, but some preventive services are covered at no cost to you.

The distinction between "hospital outpatient" and "office-based" matters for your bill. If your doctor performs a procedure in their office, you pay office-based coinsurance. If the same doctor performs it in a hospital outpatient center, you pay hospital outpatient coinsurance, which is often higher. Always ask whether a procedure will be done in an office or a hospital setting.

What happens when a provider does not accept Medicare

A provider who does not accept Medicare can still treat you and bill you directly. However, they must tell you in writing before treatment that they do not accept Medicare and that you will owe the full bill. You can then decide whether to proceed. This is called an "opt-out" arrangement, and it requires a signed contract.

If a provider opts out, Medicare will not pay them anything, and you cannot submit a claim to Medicare for reimbursement. You are responsible for the full cost. Some people choose opt-out providers because they believe the provider offers better care or a different approach, and they are willing to pay out of pocket.

Opt-out arrangements are uncommon but do exist, particularly among certain specialists. Before you agree to opt-out treatment, understand that you are paying the full bill yourself and that your Medigap or Medicare Advantage plan may not cover it either. Ask the provider for an estimate in writing.

How Medicare Advantage plans change the payment system

If you have a Medicare Advantage plan (Part C), the payment system is different. Medicare does not pay providers directly. Instead, Medicare pays a fixed amount per month to your insurance plan, and the plan pays providers. The plan sets its own payment rates, which may be higher or lower than Medicare's rates.

This means your out-of-pocket costs depend on your plan's network and payment agreements, not on Medicare's allowed amounts. You may have a copay instead of coinsurance, and the copay amount is set by your plan. If you go out of network, your plan may not cover the service at all, or may cover it at a much higher cost to you.

Medicare Advantage plans must cover everything Original Medicare covers, but they can organize payment and access differently. Some plans have lower copays for office visits but higher copays for specialists. Understanding your specific plan's payment structure is important for predicting your costs.

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

You can look up Medicare's allowed amount for a specific service using the Medicare Physician Fee Schedule Look-Up Tool on CMS.gov. You enter the procedure code (ask your doctor's office for this) and your state, and the tool shows you the allowed amount and the payment split between Medicare and you.

For hospital services, the process is less transparent. You can call the hospital's billing department and ask what the DRG or OPPS rate is for your procedure, but hospitals are not always quick to provide this information. A patient advocate at the hospital can sometimes help.

Your doctor's office can also tell you what Medicare will pay for a service and what you will owe. Ask them to check your deductible status and give you an estimate before your appointment. This is especially important for expensive procedures or specialist visits.

Frequently Asked Questions

Can a doctor charge me more than Medicare allows?

Only if they have opted out of Medicare and you have signed an opt-out contract beforehand. If your doctor accepts Medicare, they are bound by Medicare's allowed amount and cannot bill you for the difference. They can bill you for your deductible and coinsurance, which is your share of the allowed amount.

Why does the same procedure cost different amounts in different places?

Medicare's allowed amounts vary by geographic location to account for differences in local costs of living, rent, and staff salaries. A procedure in an urban area typically has a higher allowed amount than the same procedure in a rural area. Hospital outpatient services also vary based on the hospital's location and teaching status.

What does it mean if my doctor is "out of network"?

In Original Medicare, there is no network — all participating doctors accept Medicare at the same allowed amount. However, if you have a Medicare Advantage plan, "out of network" means the doctor does not have a contract with your plan. You may owe more or the plan may not cover the service. Check your plan's provider directory before scheduling.

Does Medicare pay the provider directly or do I pay and get reimbursed?

Medicare pays the provider directly in almost all cases. You pay your deductible and coinsurance to the provider, and Medicare sends its share to the provider. You do not pay the full bill upfront and then seek reimbursement. The exception is if you see an opted-out provider, in which case you pay them directly and cannot seek reimbursement from Medicare.

How do I know if my doctor accepts Medicare?

Use the Medicare "Care Provider Search" tool on Medicare.gov. Enter your doctor's name and location, and the tool will tell you whether they are a participating provider (accepts Medicare), non-participating (does not accept but may still treat you), or opted out. You can also call your doctor's office and ask directly.