what is coinsurance?
Coinsurance. Coinsurance is a health care cost sharing between you and your insurance company. The cost sharing ranges from 80/20 to even 50/50. For example, if your coinsurance is 80/20, that means that your insurer covers 80% of annual medical expenses and you pay the remaining 20%. The cost sharing stops when medical expenses reach your out-of-pocket maximum, which usually is between $1,000 and $5,000.