How Medicare Works?

How does Medicare work?

Generally, you only need to sign up for Part A and Part B once. Each year, you can choose which way you get your health coverage (and add or switch drug coverage).
Medicare is different from private insurance — it doesn’t offer plans for couples or families. You don’t have to make the same choice as your spouse.

2 steps to set up your Medicare coverage:

Sign up for Part A (Hospital Insurance) and Part B (Medical Insurance)
You can sign up at certain times. Check when and how to sign up.
Choose which way you want to get your Medicare health coverage
You can choose either Original Medicare or Medicare Advantage (Part C) for your health coverage.
If you choose Original Medicare, you’ll also decide if you want drug coverage (Part D) and supplemental coverage, like Medigap.

How does Original Medicare work?

Original Medicare covers most, but not all of the costs for approved health care services and supplies. After you meet your deductible, you pay your share of costs for services and supplies as you get them. There’s no limit on what you’ll pay out-of-pocket in a year unless you have other coverage (like Medigap, Medicaid, or employee or union coverage). Get details on cost saving programs.

Services covered by Medicare must be medically necessary. Medicare also covers many preventive services, like shots and screenings. If you go to a doctor or other health care provider that accepts the Medicare-approved amount, your share of costs may be less. If you get a service that Medicare doesn’t cover, you pay the full cost.

With Original Medicare, you can:

Go to any doctor or hospital that takes Medicare, anywhere in the U.S. Find providers that work with Medicare.
Join a separate Medicare drug plan (Part D) to get drug coverage.
Buy a Medicare Supplement Insurance (Medigap) policy to help lower your share of costs for services you get.
If you have other insurance, learn how Original Medicare works with your other coverage.


If you're not lawfully present in the U.S., Medicare won't pay for your Part A and Part B claims, and you can't enroll in a Medicare Advantage Plan or a Medicare drug plan.