Your share of the costs of a covered healthcare service, calculated as a percent (for example, 20%) of the allowed amount for the service. You pay coinsurance plus any deductibles you owe. For example, if the health insurance or plan’s allowed amount for an office visit is $80 and you’ve met deductible (if applicable), your coinsurance payment of 20% would be $16. The health insurance or plan pays the rest of the allowed amount.