Where policy excess or deductibles are a set amount of money, copay or coinsurance is a percentage of your expenses. Both are ways to save on paying a higher premium. Copay or coinsurance works hand in hand with insurance so that both pay when treatment is done or a physician is consulted. In deductibles, you have to pay out the excess before any claims on the insurance can be made. Both options are available at the time of buying policies. Individuals can choose whichever payment plan suits them best.