Medigap (also called Medicare Supplement) is a highly regulated and standardized supplemental insurance that pairs with Original Medicare.
Unlike Medicare Advantage, Medigap is not part of Medicare. Medigap is sold by private companies. It is insurance to fill in the cost-sharing gaps of Original Medicare.
Medigap does not include drug coverage. However, Medigap can be paired with a standalone Part D drug plan.
You must have Original Medicare Part A and B to get Medigap.