Before purchasing Medicare Part D, make sure your insurance provider has a network of retail pharmacies that are convenient for you. When it is time to renew a drug prescription, you will never pay full price. You will simply pay a copay or coinsurance, and your insurance provider will cover the rest! When it is time to obtain your drugs you will not have to pay full price. After presenting your Medicare Part D credentials, you will simply pay a copay, or coinsurance, and your insurance provider will cover the rest!