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

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Example Sentences

See Examples For:

coinsurance

But some Medicare Advantage plans are increasing copays for specialists or switching to coinsurance, which means you pay a share of the total cost, rather than a flat amount.

From The Wall Street Journal ● Oct. 15, 2026

A Medicare supplement plan, or Medigap, is extra insurance you can buy from a private health-insurance company to help cover out-of-pocket costs in traditional Medicare, like copayments, coinsurance and deductibles.

From MarketWatch ● Aug. 18, 2026

Medigap policies sit alongside traditional Medicare plans and are optional coverage designed to pay for uncovered costs like copayments, coinsurance, and deductibles.

From Barron's ● Jun. 4, 2026

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

From MarketWatch ● May 30, 2026

An employer could have a health plan that pays for expensive drugs with 20% employee coinsurance.

From The Wall Street Journal ● Nov. 13, 2025

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