Medigap (or Medicare supplement Insurance) are standardized insurance health coverage plans provided by licensed private Insurance companies in most states nationwide that help you pay the additional out-of-pocket- health costs that Medicare (part A and B) does not cover.
All Medigap plans, each denoted by a letter, provide the same basic benefits regardless of the company you are registered with. The costs of the Medigap Insurance policy plans however may vary from one Insurance company to the other, and across states, hence it is necessary to compare rates so you can select the plan most suitable for you.
Every year Medicare publishes a guide to choosing a Medigap policy. Below is the Medicare guide for 2022.