Following is a definition of coinsurance along with examples. Let me know
if you need further clarification.
In property insurance, the percentage of the market value of a property the
policyholder is required to insure. For example, with a coinsurance clause
of 80%, a $200,000 house must be insured for at least $160,000. Insurance
coverage of less than this results in a reduced reimbursement in the event
of a claim.
Case Study The coinsurance clause included in property insurance policies
can result in an unpleasant surprise for a homeowner who files a
substantial claim. Unlike coinsurance, or copay, in health insurance, in
which the insured and insurer each agree to pay a predetermined portion of
any claim, coinsurance applied to property insurance is the percentage of
value a policyholder is required to insure. For example, a home with a
value of $300,000 and an 80% coinsurance clause must be insured for at
least $240,000. Coverage of less than the required amount will result in
the insurance company paying a reduced amount for a claim, even if the
claim is less than the amount of coverage. Suppose the homeowner in the
above example carries $200,000 of coverage, $40,000 less than required by
the coinsurance clause. A fire causing damage of $150,000 will result in an
insurance reimbursement equal to the proportion of actual coverage compared
to the required coverage times the amount of the claim. In this case,
reimbursement is ( $200,000/$240,000 ) × $150,000, or $125,000, less any
deductible. Nearly all property insurance policies contain a coinsurance
clause.