(1) A property insurance provision that penalizes the insured's loss recovery if the limit of insurance purchased by the insured is not equal to or greater than a specified percentage (commonly 80 percent) of the value of the insured property. The coinsurance provision specifies that the insured will recover no more than the following: the amount of the loss multiplied by the ratio of the amount of insurance purchased (the limit of insurance) to the amount of insurance required (the value of the property on the date of loss multiplied by the coinsurance percentage), less the deductible. The amount of the loss that is not payable to the insured as a result of failure to comply with the coinsurance provision is commonly referred to as a coinsurance penalty. In commercial property insurance policies, it is sometimes possible to avoid the possibility of a coinsurance penalty with an agreed value provision. (2) In health insurance and some casualty lines, the percentage share of losses that an insured retains. It is a form of deductible.