Medicare
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.
Medicare Supplements
A Medicare supplement (Medigap) insurance, sold by private companies, can help pay some of the health care costs that 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 US. 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 Part D
Each Medicare Prescription Drug Plan has its own list of covered drugs (called a formulary). Many Medicare drug plans place drugs into different "tiers" on their formularies. Drugs in each tier have a different cost.
A drug in a lower tier will generally cost you less than a drug in a higher tier. In some cases, if your drug is on a higher tier and your prescriber thinks you need that drug instead of a similar drug on a lower tier, you or your prescriber can ask your plan for an exception to get a lower copayment.