A Medicare supplement (Medigap) insurance, sold by private companies, can help pay some of the health care costs that Original Medicare doesn't cover, like copayments, coinsurance, and deductibles.
Some Medigap policies also offer coverage for services that Original Medicare doesn't cover, like medical care when you travel outside the U.S. If you have Original Medicare and you buy a Medigap policy, Medicare will pay its share of the Medicare-approved amount for covered health care costs. Then your Medigap policy pays its share.
A Medigap policy is different from a Medicare Advantage Plan. Medigap plans work with Original Medicare. With Original Medicare, you can go to any doctor or hospital that accepts Medicare, and there are no referrals required for specialists.
Medigap policies generally don't cover long-term care, vision or dental care, hearing aids, eyeglasses, or private-duty nursing.
Some types of insurance aren't Medigap plans, they include: