The shared cost between the covered person and the insurance company for specified covered services. Co-insurance percentages vary between plans and is usually expressed as a percentage split, where the covered person pays a certain percentage and the insurance company pays the rest. Co-insurance begins after your deductible is met and goes towards your out-of-Pocket Maximum amount. Once your Out-of-Pocket Maximum is reached in a Calendar Year, you will not be required to pay a co-insurance amount for the remainder of the Calendar Year.