Question

a fixed dollar amount that you agree to pay each time you receive medical treatment, such as a doctor’s visit or prescription

Explanation:

The definition describes a fixed amount paid for medical services like doctor visits or prescriptions, which is the concept of a "copayment" (or "copay"). This term is used in healthcare (Medicine and Health subfield of Natural Science) to refer to the fixed out - of - pocket cost a patient pays for each covered medical service.

Answer:

Copayment (or Copay)