Medicare Part B helps pay for care you receive in a clinic or hospital as an outpatient. Part B also covers most doctor services you receive as a hospital inpatient. Most other hospital services are covered by Part A.
What Does Medicare Part B Cover?
Medicare Part B covers doctor visits and most routine and emergency medical services. It also covers some preventive care, like flu shots. The list below shows more examples of what Part B covers.

What Does Medicare Part B Cost?
Medicare Part B shares some costs with you when you see the doctor or use other medical services. The table below shows the different costs that may apply. Costs shown are for 2021.
Part B charges a monthly premium. The payment is deducted from your monthly check if you receive Social Security benefits. Otherwise you need to send a monthly premium payment to Medicare.
Medicare Part B pays 80% of the cost for most outpatient care and services, and you pay 20%. But there is something called “Medicare assignment” that’s important to understand.
Doctors and providers who accept Medicare assignment agree to take what Medicare pays—the Medicare-approved amount—as payment in full. Medicare reduces the approved amount it pays for doctors who don’t accept Medicare assignment.
Doctors who don’t accept Medicare assignment may charge more than the Medicare-approved amount. You may have to pay the additional cost, which is called “excess charges.”
Ellen's story may help you understand how Part B cost sharing might work when doctors accept Medicare assignment and when they don't.