Coinsurance

A percentage of medical expenses you cover once you've hit your deductible

tl;drA fixed percentage of your medical bill that you'll pay for a covered service once you’ve already hit your deductible. You won’t have to pay this anymore once you hit your out-of-pocket maximum.

What is co-insurance?

Co-insurance is the percentage of medical expenses that you’re responsible for paying after you have met your deductible.

For example, if a health insurance plan has a co-insurance requirement of 20% and you’ve already met your deductible, and then you have a $500 medical expense, you would be responsible for paying 20% of the remaining $500, or $100. The insurance company would pay the remaining $400.

Co-insurance generally exists between your deductible and your out-of-pocket maximum. Once you've paid your full deductible, co-insurance kicks in, and you pay a percentage of expenses. This stops when you hit your out-of-pocket maximum for the year, at which point the insurance company pays 100% of covered medical expenses.