Medicare Supplement

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. Those plans are ways to get Medicare benefits, while a Medigap policy only supplements your Original Medicare benefits.

Medicare Advantage

 

A Medicare Advantage Plan is a type of Medicare health plan offered by a private company that contracts with Medicare to provide you with all your Part A and Part B benefits. Medicare Advantage Plans include Health Maintenance Organizations, Preferred Provider Organizations, Private Fee-for-Service Plans, Special Needs Plans, and Medicare Medical Savings Account Plans. If you're enrolled in a Medicare Advantage Plan, Medicare services are covered through the plan and aren't paid for under Original Medicare. Most Medicare Advantage Plans offer prescription drug coverage.

Health Insurance Medicare Part A, B, C and D

Medicare covers services (like lab tests, surgeries, and doctor visits) and supplies (like wheelchairs and walkers) considered medically necessary to treat a disease or condition.
If you're in a Medicare Advantage Plan or other Medicare plan, you may have different rules, but your plan must give you at least the same coverage as Original Medicare. Some services may only be covered in certain settings or for patients with certain conditions.