A co-pay requires the insured to pay a specified amount of out-of-pocket expenses for health care services such as doctor visits and prescriptions drugs at the time the service is rendered, with the insurer paying the remaining costs. Co-pay fees will vary among insurers but are typically very affordable. For example, a co-pay plan may require the insured to pay $25 per doctor visit or $10 per prescription up to a specified coverage limit.
With a coinsurance, a health plan will require you to pay a percentage rate meaning that you will essentially be splitting the cost of your healthcare with the insurance carrier. For instance, if the health plan has an 80/20 coinsurance rate, the insurance plan pays for 80% of the eligible medical expenses and you are responsible for the remaining 20%.