What distinguishes a copayment from coinsurance in healthcare billing?

A copayment is a predetermined, fixed amount that a patient pays for healthcare services at the time of receiving care, such as a doctor's visit or a prescription. This fee is usually stated in the patient's insurance plan and is designed to share the cost of healthcare between the insurer and the insured. The flat nature of copayment makes it easy for patients to understand and budget for their healthcare expenses, as they know the exact amount they will owe for specific services.

In contrast, coinsurance represents a percentage of the total cost of a service that the patient is responsible for after the deductible has been met. This means that the actual dollar amount paid by the patient can vary depending on the total cost of the service, which makes coinsurance a more variable cost compared to the fixed nature of a copayment. Therefore, the distinction between the two is primarily based on how the payment is structured: a flat fee for copayment versus a percentage of total costs for coinsurance.