DEDUCTIBLE

A set amount of your medical services that you pay before your insurance starts paying a portion of your expenses.

CO-INSURANCE 

Once you meet your deductible you pay a portion of your covered medical services and your insurance pays the remaining portion.

Copay

A set amount of a medical service you are required to pay at the time of service. You may additionally have to pay off a deductible and may also have a Co-insurance depending on your plan.