A fixed amount ($20, for example) you pay for a covered health care service after you've paid your deductible.
Let's say your health insurance plan's allowable cost for a doctor's office visit is $100. Your copayment for a doctor visit is $20.
Copayments (sometimes called "copays") can vary for different services within the same plan, like drugs, lab tests, and visits to specialists.
Generally plans with lower monthly premiums have higher copayments. Plans with higher monthly premiums usually have lower copayments.