Medicare doesn't pay any of the costs for you to get a Medigap policy. You have to pay the premiums for a Medigap policy.
Medigap helps pay your Part B bills
In most Medigap policies, the Medigap insurance company will get your Part B claim information directly from Medicare. Then, they pay the doctor directly. Some Medigap insurance companies also provide this service for Part A claims.
If your Medigap insurance company doesn't provide this service, ask your doctors if they "participate" in Medicare. This means that they "accept assignment" for all Medicare patients. If your doctor participates, the Medigap insurance company is required to pay the doctor directly if you request it.
Compare the costs of Medigap plans
Insurance companies may charge different premiums for the same exact policy. As you shop for a policy, be sure you're comparing the same policy. For example, compare Plan A from one company with Plan A from another company.
In some states, you may be able to buy another type of Medigap policy called Medicare SELECT. If you buy a Medicare SELECT policy, you have the right to change your mind within 12 months and switch to a standard Medigap policy.