What is Coinsurance? Typically, coinsurance is a cost-sharing requirement where you are responsible for paying a certain percentage and the insurance company will pay the remaining percentage of the covered medical expenses after your deductible is met.
For a health insurance plan with 20% coinsurance, once the deductible is met, the insurance company will pay 80% of the covered expenses while you pay the remaining 20% until your out-of-pocket limit is reached for the year.