An insurance copay (copayment) is a fixed dollar amount you pay for a covered health care service, often at the time you receive it. HealthCare.gov defines it as a set amount—for example $20—for a covered service after you have paid your deductible.
Copays can differ by service within the same plan (doctor visits, prescriptions, lab tests, specialists). If you have not yet met your deductible, you may owe the plan’s full allowable amount for that visit instead of only the copay. Plans with lower monthly premiums generally have higher copays, and plans with higher premiums usually have lower copays.
Source: Copayment, HealthCare.gov Glossary
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