What best describes coinsurance?

• A. Fixed amount paid at point of service
• B. Monthly premium
• C. Total cost of care
• D. Percentage of costs paid by patient after deductible

Answer: (D)

Coinsurance is the share of medical costs that the patient pays after the deductible has been met, typically expressed as a percentage. After meeting the deductible, you might pay a percentage of the allowed charges (for example, 20%), with the insurer covering the remainder until you reach your out-of-pocket maximum. This distinguishes coinsurance from a fixed co-pay (a set amount paid at the time of service), a monthly premium (a fixed payment regardless of care), and the total cost of care (the full charge before applying cost-sharing). Therefore, describing coinsurance as a percentage of costs paid by the patient after the deductible best captures how it works.