Medigap
A Medigap (Medicare Supplement) policy is private insurance that pays some of the cost-sharing a beneficiary owes under Original Medicare, after Medicare pays its share.
Updated
A Medigap policy — also called a Medicare Supplement Insurance plan — is a private insurance product sold to people with Original Medicare that helps pay the cost-sharing Original Medicare does not cover, such as deductibles, coinsurance, and copayments. It is designed to fill the gaps in Original Medicare, not to replace it.
Medigap plans are standardized by lettered plan types (A through N in most states), each with a defined set of benefits, so two insurers' plans of the same letter cover the same benefits. A Medigap policy works with Original Medicare only and is not compatible with Medicare Advantage.
In practice
For a provider, a Medigap policy is secondary to Original Medicare: Medicare adjudicates and pays its allowed amount, the Medigap policy pays some or all of the remaining beneficiary cost-sharing, and the provider's claim is typically processed automatically between the two without a separate patient balance — provided the Medigap payer is correctly identified and billed.
Commonly confused with
- Medicare Advantage: A Medigap policy supplements Original Medicare cost-sharing; Medicare Advantage replaces Original Medicare with a private plan. A beneficiary cannot carry both a Medigap policy and a Medicare Advantage plan that delivers the same benefits.
- Secondary insurance: Medigap is a form of secondary coverage, but a general secondary insurance plan can be a commercial or Medicaid plan with its own network and rules; a Medigap policy only fills Original Medicare cost-sharing.