What does co-insurance mean?

Co-insurance refers to the percentage of medical costs that you are required to pay under the terms of your health insurance policy. When your policy has a coinsurance provision, it is normally expressed in terms of a ratio such as 80-20. In this example, the insurer would pay 80 percent of your covered healthcare costs, and you would pay the remaining 20 percent of your costs. The insurer begins paying their percentage of costs after you’ve already paid your deductible (if your policy has a deductible), and you will be responsible for yours up to the coinsurance limit, at which point your insurer becomes responsible for paying for 100 percent of the cost of care up to policy limits.