What is the term for the fixed percentage members pay of the cost of each prescription?

The correct term for the fixed percentage that members pay of the cost of each prescription is co-insurance. Co-insurance refers to a cost-sharing arrangement where the insured pays a specific percentage of the total cost of a medical service. With medications, this means that after reaching any applicable deductibles, members would pay a certain percentage of the prescription price, while the insurance plan covers the remaining percentage.

In contrast, a co-payment is typically a fixed dollar amount that a patient pays for a specific service, such as a prescription or doctor's visit, rather than a percentage of the total cost. A deductible represents the amount a member must pay out-of-pocket before their insurance begins to cover costs, which is different from the share of a bill incurred after the deductible has been met. An annual limit refers to the maximum amount that an insurance plan will pay for covered expenses in a year, which does not directly relate to how much a member pays for each prescription.