Health insurance glossary
Co-payment and coinsurance
Plain-English definition
A co-payment is a fixed dollar amount you pay each time you use a covered service, such as a set fee per prescription. Coinsurance is a percentage of the cost that you pay, with the plan paying the rest. Many plans combine them with a deductible and an annual maximum, so the share you pay can change through the year.
By the HealthRate editorial desk
How it works
Public drug programs use both. Some charge a flat amount per prescription; others charge a percentage of each prescription up to a cap per prescription or per year. How each province sets its share is laid out in our guide to what provincial plans leave uncovered.
Private plans often state coinsurance as the percentage they reimburse rather than the percentage you pay. Read which way your plan states it: a plan that pays a percentage of an eligible expense leaves the remaining percentage to you.
Caps matter as much as the rate. A percentage with a per-prescription or yearly maximum limits what you can owe; a percentage with no cap does not.
Why it matters
On an expensive drug or treatment, a percentage share can cost far more than a flat fee. Knowing which one a plan uses, and whether it has a cap, tells you what a high-cost claim would cost you.
Not to be confused with
Neither is the deductible. A deductible is what you pay before the plan starts sharing costs; co-payments and coinsurance apply after it.