coinsurance

noun

co·​in·​sur·​ance ˌkō-ən-ˈshu̇r-ən(t)s 

 also  -ˈin-ˌshu̇r-

1

: joint assumption of risk (as by two underwriters) with another

2

: insurance (such as fire insurance) in which the insured is obligated to maintain coverage on a risk at a stipulated percentage of its total value or in the event of loss suffer a penalty in proportion to the deficiency

3

: health insurance in which the insured is required to pay a fixed percentage of the cost of medical expenses after the deductible has been paid and the insurer pays the remaining expenses

Coinsurance is not a new idea—Americans who grew up in the era before managed care will remember their parents paying 20% of the costs of office visits, tests, and prescriptions.

—Thomas H. Lee et al.

Examples of coinsurance in a Sentence

Recent Examples on the Web

This limit applies to deductibles, copayments, and coinsurance for covered drugs but doesn’t apply to premiums.1 The cap also doesn’t apply to drugs not covered by your plan. —Fran Kritz, Verywell Health, 3 Oct. 2024

Medicare Cost-Savings Programs: Also provided by the Pennsylvania Department of Aging, these three programs can help lower-income older adults pay their Medicare premiums, deductibles, coinsurance, copayments and prescription drug costs. —Robby Brumberg, Forbes, 29 Sep. 2024

Because this is a much more significant impact than elimination of the 5% coinsurance, CMS is rightfully concerned about the variation in premiums between stand-alone Part D plans and MA-PD plans (Medicare Advantage plans that include drug coverage). —Diane Omdahl, Forbes, 1 Oct. 2024

Almost a third of drug plans changed a copayment to a coinsurance. —Diane Omdahl, Forbes, 17 Sep. 2024

Word History

First Known Use

circa 1889, in the meaning defined at sense 1

Medical Definition

coinsurance

noun

co·​in·​sur·​ance ˌkō-ən-ˈshu̇r-ən(t)s, -ˈshər- also -ˈin-ˌshu̇r-, -ˌshər- 

: health insurance in which an insurer requires the insured to pay a fixed percentage of the cost of medical expenses after the deductible has been paid and with the insurer to pay the remaining expenses

Coinsurance is not a new idea—Americans who grew up in the era before managed care will remember their parents paying 20% of the costs of office visits, tests, and prescriptions.

—Thomas H. Lee et al., The New England Journal of Medicine

Legal Definition

coinsurance

noun

co·​in·​sur·​ance ˌkō-in-ˈshu̇r-əns, kō-ˈin-ˌshu̇r- 

1

: joint assumption of risk (as by two underwriters) with another

2

: insurance (as fire insurance) in which the insured is obligated to maintain coverage on a risk at a stipulated percentage of its total value or in the event of loss to suffer a penalty in proportion to the deficiency