Original Medicare pays for many health care services, but not all. Medicare Supplement plans are also called Medigap policies. Medicare Supplement insurance policies can help pay some of the costs that Original Medicare does not cover. These are standardized policies sold by private insurance companies and designed to fill in the gaps in Original Medicare.

A Medicare Supplement policy can help cover copayments, coinsurance and deductibles. Medicare will pay for its share of the Medicare-approved amount for covered health care costs, and then your Medicare Supplement policy will pay its share. If you join a Medicare Advantage Plan you can’t use a Medicare Supplement policy. You must have Part A and Part B Medicare for a Medicare Supplement plan.