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Personal finance glossary

Coinsurance

Definition

The percentage of a medical bill you keep paying after meeting your deductible, until you hit the plan's out-of-pocket maximum. An 80/20 plan means insurance pays 80% and you pay 20% in that middle zone.

Why it matters

People budget for the deductible and forget coinsurance, which is often the larger number in a serious year. The out-of-pocket maximum, not the deductible, is the real worst-case figure for emergency planning.

Example

A $10,000 procedure on an 80/20 plan with a $2,000 deductible: you pay the first $2,000, then 20% of the remaining $8,000 ($1,600), a total of $3,600, unless the plan's out-of-pocket maximum caps it sooner.

Put it into practice

Related terms

This definition is educational, not financial, legal, or tax advice. U.S. rules and limits change; verify time-sensitive details with official sources. See our disclaimer.

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