Medicare Supplement Insurance, known as Medigap, consists of private insurance policies designed to “fill the gaps” in Original Medicare(Part A and B). Because Original Medicare generally pays for about 80% of covered medical expenses, Medigap plans help beneficiaries cover the remaining out-of-pocket costs, such as deductibles, coinsurance, and copayments.
Medigap is specifically designed to work only with Original Medicare. It functions as secondary insurance to enhance a beneficiary’s primary federal coverage.