How does a deductible fundamentally differ from a copayment regarding payment sequence?

The deductible is the total amount paid before the plan starts paying; a copayment is a fixed amount paid for certain services, often even after the deductible is met.

The deductible and the copayment serve distinct roles in the cost-sharing structure. A deductible is the aggregate dollar amount that the insured person must pay entirely out-of-pocket for covered health care services before the insurance plan begins to share in the costs. Once the deductible is satisfied, the cost-sharing shifts. A copayment, conversely, is a predetermined, fixed dollar amount that the policyholder pays for specific covered services, such as seeing a physician or picking up a prescription. Importantly, copayments are often required every time that specific service is accessed, and many plans stipulate that these fixed copayments must still be paid even after the deductible has been fully met. Some plans may waive deductibles for certain services like preventive care, but the fundamental difference lies in the deductible being a cumulative threshold and the copayment being a fixed transactional fee.