In a health policy, coinsurance represents the percentage of the medical bills the insured will be responsible to pay after the deductible is met.
For example, if your policy is “80% coinsurance”, then once the deductible is met, the insurance will pay 80% of covered medical bills and you pay 20%. Typically there will also be a provision called a “stop-loss”, which is basically a maximum amount you will ever have to pay out of your own pocket for covered medical bills.
Let’s say your policy states it is “80% coinsurance, with a $1,000 stop-loss.” Once you’ve paid your deductible, your covered medical bills are $7,000.
Here’s how that would work:
First, the coinsurance provides the carrier will pay 80% of the $7,000 ($5,600) and you will pay 20% ($1,400). But, your “stop-loss” says your maximum payable for this claim is $1,000! So you only pay the $1,000, and the additional $400 comes from your insurance company. Notice this provision gets more valuable as the claim gets larger—no matter how large the final claim, or what percentage of coinsurance you’ve purchased, your stop-loss says your share of the covered expenses will never exceed $1,000.
Please note some polices refer to “stop-loss” as “maximum out-of-pocket”. And many polices include the amount of the deductible in determining when you hit your maximum, also a helpful provision.