Get More Info: Medicare Supplement 

Also known as Medigap, exists to cover out-of-pocket costs, such as co-payments or deductibles. You will still have Original Medicare parts A and B. Medigap functions as an add-on policy to Original Medicare. These policies are standardized and go by letters: A, B, C, D, F, G, K, L, M, and N in most states. Each lettered plan’s benefits are the same, no matter which insurance company sells it. You will have access to any Medicare-appointed doctor in the U.S.