Original Medicare pays for many, but not all, health care services and supplies. A Medigap policy is private insurance that helps supplement Original Medicare. This means it helps pay some of the health care costs that Original Medicare doesn’t cover (like copayments, coinsurance, and deductibles). These are “gaps” in Medicare coverage. If you have Original Medicare and a Medigap policy, Medicare will pay its share of the Medicare-approved amounts for covered health care costs. Then your Medigap policy pays its share.

A Medigap policy is different from a Medicare Advantage Plan (like an HMO or PPO) because those plans are ways to get Medicare benefits, while a Medigap policy only supplements the costs of your Original Medicare benefits. Note: Medicare doesn’t pay any of your costs for a Medigap policy.