coinsurance

American  

[koh-in-shoor-uhns, -shur-] / ˌkoʊ ɪnˈʃʊər əns, -ˈʃɜr- /

noun

1. insurance underwritten jointly with another or others.

2. a form of property insurance in which an insurer assumes liability only for that proportion of a loss which the amount of insurance bears to a specified percentage of the value of the property.

3. 1. a form of health insurance in which the insured party contributes a specified percentage of the total cost of medical expenses after a deductible has been reached.

   2. the percentage contributed by the insured party.

      My coinsurance is 20%.

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coinsurance British  

/ ˌkəʊɪnˈʃʊərəns, -ˈʃɔː- /

noun

1. a method of insurance by which property is insured for a certain percentage of its value by a commercial insurance policy while the owner assumes liability for the remainder

2. joint insurance held by two or more persons

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Etymology

Origin of coinsurance

First recorded in 1885–90; co- + insurance

Example Sentences

See Examples For:

coinsurance

Americans are paying more out of pocket for healthcare in the form of deductibles, copayments and coinsurance, as well as expenses not covered by their insurance, according to federal data.

From The Wall Street Journal ● Aug. 20, 2026

The estimate includes Medicare premiums, out-of-pocket prescription-drug costs and other medical expenses such as copayments, coinsurance and deductibles for doctor and hospital visits.

From MarketWatch ● Jul. 21, 2026

In addition to premiums, expect to pay deductibles, copayments, coinsurance and prescription-drug costs.

From MarketWatch ● May 30, 2026

That includes copayments, coinsurance, and deductibles but excludes monthly premium costs.

From Barron's ● Mar. 5, 2026

Patients with deductibles or coinsurance then get hit with out-of-pocket costs tied to that inflated list price, while the rebate money flows back to insurers or employers to lower premiums for the broader pool.

From The Wall Street Journal ● Dec. 12, 2025