Medicare Supplement or Medigap Insurance fills the gaps in Original Medicare.
It helps pay some of the remaining health care costs, like copayments, coinsurance and deductibles.
Medicare will pay its share of the Medicare approved amount for covered services, then the Medigap plan pays its share.
Some Medigap plans sold prior to January 1, 2006 covered prescription drugs. However, most individuals need to purchase a separate Part D plan to go with their Medigap plan.