As of 2013, there are 10 Medicare Supplement (Medigap) Plans to choose from. They are standardized as Plans A, B, D, D, F, G, L, M, AND N. Each plan has different premiums and coverage areas. However, the standardization of these plans makes it easy to compare between various insurers since the Medigap plans must offer the same coverage. THE MAIN DIFFERENCE IS PRICE between the insurers.