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

Medicare Part A is hospital insurance. It pays for inpatient hospital stays, skilled nursing facility care after a hospital stay, hospice care, and some home health services. You do not pay a monthly premium for Part A if you or your spouse paid Medicare taxes while working — it is included in what you earned.

Medicare Part B is medical insurance. It pays for doctor visits, outpatient care, lab tests, imaging, durable medical equipment (like wheelchairs or oxygen), and preventive services such as screenings and vaccines. Part B requires a monthly premium, which changes each year based on your income.

Together, Part A and Part B make up Original Medicare. Many people have both, though you can have Part A without Part B if you choose. Part B is optional, but if you delay signing up when you first become may be able to access, you may pay a penalty for as long as you have Medicare.

Key Takeaways

  • Part A covers hospital stays and skilled nursing care after hospitalization, with no monthly premium if you paid Medicare taxes while working.
  • Part B covers doctor visits, outpatient services, and preventive care, and requires a monthly premium that varies by income.
  • You are automatically enrolled in Part A at age 65, but you must actively enroll in Part B during your initial enrollment window or face a lifetime penalty.
  • Part A has a deductible per hospital stay and Part B has an annual deductible, plus you pay coinsurance or copayments for services.
  • Original Medicare (Part A and Part B together) does not cover dental, vision, hearing aids, or prescription drugs — those require separate coverage.

What Part A actually pays for

Part A covers an inpatient hospital stay from the moment you are admitted until you are discharged. It pays for your room, meals, nursing care, medications, and lab work while you are in the hospital. The coverage is limited to medically necessary care — elective procedures you choose for non-medical reasons are not covered.

After you leave the hospital, Part A also covers skilled nursing facility care if your doctor orders it and you meet specific conditions: you must have been in the hospital for at least three consecutive days, you must be admitted to the facility within 30 days of leaving the hospital, and the care must be for the same condition that sent you to the hospital or a related one. Part A covers up to 100 days in a skilled nursing facility per benefit period, though you pay coinsurance after day 20.

Part A covers hospice care when your doctor and another doctor agree you have six months or less to live. It also covers some home health services — primarily skilled nursing visits and physical therapy — when you are homebound and your doctor orders the care. Home health aide services (help with bathing or dressing) are covered only if skilled care is also being provided.

What Part B actually pays for

Part B covers visits to doctors, specialists, and other healthcare providers such as nurse practitioners and physician assistants. It pays for office visits, urgent care visits, and emergency room visits. It also covers outpatient surgery, diagnostic tests like blood work and imaging, and mental health counseling.

Part B pays for preventive services at no cost to you — these include annual wellness visits, cancer screenings, cardiovascular screenings, diabetes screenings, bone density tests, and vaccines such as flu, pneumonia, and shingles shots. You do not pay a copayment or coinsurance for these preventive services when you see a provider who accepts Medicare.

Part B also covers durable medical equipment — items your doctor prescribes that you can use repeatedly, such as wheelchairs, walkers, oxygen equipment, and diabetic supplies. It covers some rehabilitation services including physical therapy, occupational therapy, and speech-language pathology, usually up to a certain number of visits per year unless your condition qualifies for an exception.

How much you pay out of pocket

Part A has a deductible per benefit period. A benefit period begins the day you enter the hospital and ends 60 days after you leave the hospital without receiving any inpatient care. If you return to the hospital within those 60 days, you are still in the same benefit period and do not owe another deductible. If you return after 60 days have passed, a new benefit period begins and you owe a new deductible. The deductible amount changes each year.

Part B has an annual deductible that resets every January. Once you meet the deductible, you typically pay 20 percent coinsurance for most services — Medicare pays 80 percent and you pay 20 percent. For some services such as office visits or outpatient surgery, you may pay a fixed copayment instead of coinsurance.

These costs add up, which is why many people also purchase a Medigap policy (supplemental insurance) to cover the deductibles and coinsurance Part A and Part B do not pay. Others choose Medicare Advantage (Part C), an alternative to Original Medicare that often has lower out-of-pocket costs but limits which doctors and hospitals you can use.

What Part A and Part B do not cover

Original Medicare does not cover dental care, vision care, or hearing aids. If you need these services, you can purchase standalone dental, vision, or hearing insurance, or you can choose a Medicare Advantage plan that includes them — though coverage varies widely by plan.

Part B does not cover prescription drugs. If you take medications, you need to enroll in Part D (prescription drug coverage) through a standalone plan or through a Medicare Advantage plan that includes drug coverage. Part D has its own monthly premium and annual deductible.

Neither part covers long-term care in a nursing home or assisted living facility, custodial care (help with daily activities when no skilled care is needed), or most over-the-counter medications and supplements. Routine foot care, routine eye exams for glasses, and most cosmetic procedures are also not covered.

When you become may be able to access and how to enroll

You become may be able to access for Medicare at age 65. You are automatically enrolled in Part A if you are receiving Social Security benefits or Railroad Retirement benefits. If you are not receiving benefits, you must contact Social Security to enroll in Part A.

Part B enrollment is not automatic. Your initial enrollment window is the three months before the month you turn 65, the month you turn 65, and the three months after. If you enroll during this window, your coverage begins the month you turn 65 or the month after, depending on when you enroll. If you miss this window and do not have other may have access to coverage, you will owe a late enrollment penalty for as long as you have Part B.

You can enroll in Part B through Social Security's website, by phone, or in person at your local Social Security office. You will need your Social Security number and information about any other health insurance you currently have.

Original Medicare versus Medicare Advantage

Original Medicare (Part A and Part B) is a fee-for-service plan run by the federal government. You can see any doctor or hospital that accepts Medicare anywhere in the country. You pay the deductibles and coinsurance described above, and you are responsible for any costs Medicare does not cover unless you have supplemental insurance.

Medicare Advantage (Part C) is an alternative to Original Medicare offered by private insurance companies. It includes Part A and Part B coverage plus usually Part D (prescription drugs) and often dental, vision, and hearing coverage. However, Medicare Advantage plans typically have networks — you must use doctors and hospitals in the plan's network, except in emergencies. Out-of-pocket costs may be lower, but the trade-off is less flexibility in choosing providers.

If you have Original Medicare, you can switch to Medicare Advantage during the annual enrollment period (October 15 to December 7). If you have Medicare Advantage, you can switch back to Original Medicare during the same window. Once you switch, you cannot switch back until the next enrollment period.

Frequently Asked Questions

Do I have to take Part B when I turn 65?

No, Part B is optional. However, if you delay enrolling and do not have other may have access to health insurance, you will owe a late enrollment penalty added to your Part B premium for as long as you have Medicare. The penalty is 10 percent of the standard Part B premium for each full year you were may be able to access but did not enroll.

What happens if I work past 65 and have employer health insurance?

If your employer has 20 or more employees and you are still working, you can delay enrolling in Part B without penalty. You have eight months after your employment ends or your employer coverage ends to enroll in Part B without owing a late penalty. You should still enroll in Part A at 65 even if you delay Part B.

Can I have both Original Medicare and Medicare Advantage at the same time?

No, you can have either Original Medicare (Part A and Part B) or Medicare Advantage (Part C), but not both. If you enroll in Medicare Advantage, your Original Medicare coverage ends. If you later switch back to Original Medicare, your previous Medigap coverage may not be available.

Does Part A cover all hospital stays?

Part A covers medically necessary inpatient hospital stays. It does not cover elective procedures or stays that are not medically necessary. Your doctor and the hospital determine whether your stay qualifies for coverage. If you disagree with a coverage decision, you have the right to appeal.

What is the difference between coinsurance and a copayment?

A copayment is a fixed dollar amount you pay for a service — for example, $15 for an office visit. Coinsurance is a percentage of the cost you pay after meeting your deductible — for example, 20 percent of the cost of an imaging test. Part B typically uses coinsurance; some services use copayments instead.