Bills and insurance
What Is Coinsurance in Health Insurance?
Coinsurance · say it: koh-in-SHUR-ensAlso written: co-insurance, cost sharing percentage
Short answer
Coinsurance is the percentage of a covered health care cost you pay after meeting your deductible, such as 20 percent of the allowed amount.
What it means
With coinsurance, you and your insurer split the allowed cost of a service by percentage. For example, under an 80/20 plan the insurer pays 80 percent and you pay 20 percent.
Coinsurance usually begins after you have met your deductible, and it continues until you reach your out-of-pocket maximum for the year.
Because it is a percentage, the amount you pay changes with the cost of the service. Your explanation of benefits shows how the coinsurance was calculated.
Where you may see it
- Explanation of benefits (EOB) statements
- Hospital and specialist bills
- Insurance plan summaries
📄 How it looks on a report
Allowed amount: $1,000.00. Plan paid: $800.00. Coinsurance (20%): $200.00
🙅 What it does not mean
- Coinsurance is based on the allowed amount, not usually the full price the provider first billed.
- It is not the same as a copay; coinsurance changes with the cost, a copay is fixed.
- Coinsurance does not go on forever; it stops once you reach your out-of-pocket maximum.
🗒️ Questions to ask your doctor
🧾 Reports where you will see “Coinsurance”
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🔗 Read more from trusted sources
- “Coinsurance” on MedlinePlus ↗
US National Library of Medicine
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