In property insurance, requires the policyholder to carry insurance equal to a specified percentage of the value of property to receive full payment on a loss. For health insurance, it is a percentage of each claim above the deductible paid by the policyholder. For a 20 percent health insurance coinsurance clause, the policyholder pays for the deductible plus 20 percent of his covered losses. After paying 80 percent of losses up to a specified ceiling, the insurer starts paying 100 percent of losses.

"Coinsurance" In Context

"Effective April 1, 2012, Kaiser Permanente's portfolio of 11 individual and family plans include a wider range of deductible options, lower family deductibles, lower annual out-of-pocket maximums, and zero coinsurance plans with Health Savings Accounts."