Part A covers hospital care, Part B covers doctor visits and outpatient services

Medicare Part A pays for inpatient hospital stays, skilled nursing facility care after a hospital stay, hospice care, and some home health services. Medicare Part B pays for doctor visits, outpatient care, diagnostic tests, and preventive services. Most people get both parts together, and they work as a pair — Part A handles what happens when you are admitted to a hospital, and Part B handles what your doctor does in the office or clinic.

If you are already on Medicare, you likely have both parts. If you are turning 65 and signing up, you will choose whether to take them. Most people do, because Part A has no monthly premium if you or your spouse paid Medicare taxes for at least 10 years while working. Part B does have a monthly premium, which varies by income.

Key Takeaways

  • Part A covers hospital inpatient stays, skilled nursing care after hospitalization, hospice, and some home health visits at no monthly premium for most people.
  • Part B covers doctor office visits, outpatient procedures, lab work, imaging, and preventive care, with a monthly premium that increases if you delay signing up.
  • You pay a deductible and coinsurance under both parts, meaning Medicare does not cover the full cost of every service.
  • Part A and Part B together do not cover dental, vision, hearing aids, or long-term custodial care in a nursing home.

What Part A actually pays for

Part A covers the cost of a hospital room, meals, nursing care, and basic medical supplies during an inpatient stay — meaning you are admitted and stay overnight. It also covers up to 100 days in a skilled nursing facility if you are admitted there directly after a hospital stay of at least three days. The facility must be for skilled care (wound care, physical therapy, medication management) rather than custodial care (help with bathing or dressing).

Part A also covers hospice care if you are diagnosed with a terminal illness and choose comfort care instead of curative treatment. It pays for some home health services — nursing visits, physical therapy, occupational therapy — if your doctor orders them and you are homebound. Home health under Part A is free; you pay nothing for these visits.

You pay a deductible for Part A hospital stays. The deductible amount changes each year. If your hospital stay is longer than 60 days, you also pay coinsurance (a daily amount) for days 61 through 90, and a higher daily amount for days 91 through 150. After 150 days, Part A stops paying.

What Part B actually pays for

Part B covers doctor office visits, whether your doctor is in a hospital clinic or a private practice. It pays for outpatient surgery, emergency room visits, diagnostic tests (blood work, X-rays, MRI scans), and preventive services like annual wellness visits, cancer screenings, and vaccinations. It also covers durable medical equipment — wheelchairs, oxygen, walkers — if your doctor prescribes it.

Part B has a monthly premium that you pay whether you use it or not. The standard premium amount changes each year. If you delay signing up for Part B when you first become may be able to access at 65, your premium increases by 10 percent for each year you wait. That increase is permanent, so signing up on time matters financially.

You also pay a yearly deductible for Part B services, and then you pay 20 percent coinsurance for most services after the deductible is met. For some services like office visits, you may pay a fixed copay instead. The exact amount depends on the service and your specific plan.

The gaps both parts leave uncovered

Part A and Part B together do not cover dental work, vision care, or hearing aids. They do not cover long-term custodial care in a nursing home — only skilled nursing care for a limited time after hospitalization. They do not cover prescription drugs (that is Part D). They do not cover routine foot care, most acupuncture, or cosmetic surgery.

Many people buy a Medigap policy (also called supplemental insurance) to cover some of these gaps, or they choose a Medicare Advantage plan (Part C) instead of Original Medicare, which may include dental and vision but has different rules about which doctors you can see. Understanding what Part A and Part B do not cover helps you decide whether you need additional coverage.

How much you actually pay out of pocket

Part A has no monthly premium for most people, but you pay a deductible when you are admitted to the hospital. Part B has a monthly premium, a yearly deductible, and then 20 percent coinsurance for most services. The exact amounts change each year.

If you use both parts in a given year, your out-of-pocket costs can add up quickly. Some people reach their deductibles and coinsurance limits early in the year, especially if they have a hospital stay or multiple doctor visits. Others use very little and pay only the Part B premium. There is no annual out-of-pocket maximum under Original Medicare (Part A and B), which is one reason many people buy supplemental coverage.

When you can sign up and what happens if you miss the important date

You become may be able to access for Medicare at 65. You can sign up during your Initial Enrollment Period, which is the three months before the month you turn 65, the month you turn 65, and the three months after. If you sign up during this window, your coverage starts the month you turn 65 (or the month after, depending on when in the month you sign up).

If you miss this window, you can still sign up during the General Enrollment Period, which runs January 1 through March 31 each year. Coverage starts July 1 if you sign up during this period. However, your Part B premium increases by 10 percent for each full year you delayed, and that increase is permanent. Part A has no penalty if you did not work and pay Medicare taxes, but if you did work and pay taxes, there is no penalty for late enrollment.

How Part A and Part B work together with other coverage

If you are still working at 65 and have health insurance through your employer, you may be able to delay Part B without penalty. You will need to sign up for Part A, but you can wait to sign up for Part B until you retire or lose the employer coverage, as long as you sign up within eight months of losing that coverage. This is called the Special Enrollment Period.

If you choose a Medicare Advantage plan (Part C), you are still using Part A and Part B coverage — the Advantage plan is an alternative way to receive those benefits through a private insurance company. You cannot have both Original Medicare (Part A and B) and a Medicare Advantage plan at the same time.

Frequently Asked Questions

Do I have to take both Part A and Part B?

You can take Part A without Part B, but most people take both. If you delay Part B, your premium increases permanently. Part A has no monthly premium for most people, so there is little reason not to take it when you turn 65.

What is the difference between Original Medicare and Medicare Advantage?

Original Medicare is Part A and Part B run by the federal government. Medicare Advantage (Part C) is an alternative way to receive Part A and Part B benefits through a private insurance company. Advantage plans often include dental and vision, but you must use doctors in their network and may pay different copays.

Does Part B cover my doctor's office visit?

Yes. Part B covers doctor office visits, whether your doctor is in private practice or a hospital clinic. You pay a copay or coinsurance (usually 20 percent after your deductible). The exact amount depends on the type of visit and your plan.

What happens if I stay in the hospital longer than 90 days?

Part A covers up to 150 days total in a hospital stay, but your coinsurance increases after day 60. Days 91 through 150 are called "lifetime reserve days," and you have only 60 of them total across your entire life. Once you use them, Part A stops paying for hospital stays.

Can I use Part A and Part B at any hospital or doctor?

Yes, as long as the provider accepts Medicare. Most do, but you should confirm before scheduling. If you choose a Medicare Advantage plan instead of Original Medicare, you must use doctors and hospitals in that plan's network.