What Is Coinsurance?

Coinsurance is the percentage of the cost of a covered service that you pay after meeting applicable requirements such as your deductible.

For example, suppose your plan has 20% coinsurance.

If the plan’s allowed amount for a covered service is $500:

20% of $500 = $100

You would pay $100, while the plan would generally pay the remaining $400, assuming the service is covered and all applicable rules are satisfied.

Coinsurance is different from a copay because a copay is generally a fixed amount, while coinsurance is a percentage.