What is considered a fixed amount that a patient pays out-of-pocket for medical services?

The correct answer is copayment, as it specifically refers to a fixed amount that a patient is required to pay at the time of receiving a medical service. This fee is typically a predetermined amount that varies depending on the type of service, such as a visit to a primary care physician versus a specialist, and it is often stipulated in the health insurance plan.

In contrast, a deductible is the total amount that a patient must pay out-of-pocket for healthcare services before their insurance coverage kicks in. Premium refers to the regular payment made to maintain an insurance policy, while coinsurance is a type of cost-sharing where the patient pays a percentage of the total cost of the service after the deductible has been met. Understanding these definitions helps clarify how out-of-pocket expenses work in the context of healthcare insurance.