Medicare beneficiaries can owe copayments under a variety of circumstances, depending on how they get their coverage and the type of medical care they need:
Original Medicare uses copayments under Medicare Part A, if a patient is hospitalized for more than 60 days. At that point, the patient begins to have a copayment for each additional day in the hospital (note that Medicare used to refer to this as “coinsurance” even though it was always a flat-dollar amount; as of 2023, they refer to it as a copay, which is consistent with how that word is used for other types of health coverage). Medicare Part B does not have copayments; it simply uses a deductible and then coinsurance. Note that out-of-pocket costs under Original Medicare can be covered by supplemental insurance (Medigap, Medicaid, or an employer-sponsored plan) if the beneficiary has that coverage.
Medicare Part D plans can have a deductible (up to $505 in 2023) and can either use coinsurance or copays for prescription drugs. The specifics vary by plan.
Medicare Advantage plans can also be designed to cover things like doctor visits and prescription drugs with copays, making them similar to the sort of private plans which many people are accustomed to prior to enrolling in Medicare.