Medicare Part A covers hospital care; Part B covers doctor visits and outpatient services
Part A pays for inpatient hospital stays, skilled nursing facility care after a hospital stay, hospice care, and some home health services. Part B pays for doctor office visits, preventive care, lab tests, X-rays, and outpatient hospital services. Together, they form the foundation of Original Medicare — the government-run plan most people turn to at age 65.
The distinction matters because Part A and Part B have different deductibles, different copayments, and different rules about what you pay. Understanding which part covers what helps you know what to expect when you receive care and what bills you might owe.
Key Takeaways
- Part A covers hospital inpatient stays, skilled nursing care after hospitalization, and hospice; Part B covers doctor visits, preventive screenings, and outpatient services.
- Part A has a single annual deductible per hospital stay; Part B has a yearly deductible and then you pay 20 percent of approved charges after that.
- Part A typically begins automatically at age 65 if you are receiving Social Security; Part B requires you to sign up during your initial enrollment window or pay a late penalty.
- Neither part covers dental, vision, hearing aids, or long-term custodial care in a nursing home, so many people add supplemental or Medicare Advantage plans for broader coverage.
What Part A Covers in Detail
Part A covers a hospital inpatient stay — meaning you are admitted to the hospital and stay overnight. It pays for your room, meals, nursing care, and most hospital services and supplies. If you need surgery, Part A covers the operating room, anesthesia, and post-operative care while you are in the hospital.
Part A also covers skilled nursing facility care, but only after a hospital stay of at least three days. You must be admitted to the nursing facility within 30 days of leaving the hospital, and a doctor must order the care. Part A pays for up to 100 days per benefit period, though you pay a daily copayment starting on day 21.
Hospice care — palliative care for people with a terminal illness — is covered by Part A when ordered by a doctor. Part A also covers some home health services, such as skilled nursing visits or physical therapy at home, if a doctor orders the care and you are homebound.
What Part B Covers in Detail
Part B covers doctor office visits, whether for a routine checkup or treatment of an illness or injury. It pays for preventive care screenings — mammograms, colonoscopies, blood pressure checks, and diabetes screenings — at no cost to you if your doctor orders them as preventive services. Part B also covers lab tests and diagnostic imaging like X-rays and ultrasounds when medically necessary.
Outpatient hospital services fall under Part B, meaning care you receive at a hospital but do not stay overnight for — such as emergency room visits, same-day surgery, or chemotherapy infusions. Part B also covers mental health services, including therapy and psychiatric visits, and rehabilitation services like physical therapy or occupational therapy in an outpatient setting.
Durable medical equipment — wheelchairs, walkers, oxygen equipment, and similar items — is covered by Part B when a doctor prescribes it. Ambulance transport is also covered when medically necessary.
How Much You Pay Under Part A and Part B
Part A has an annual deductible per benefit period (a benefit period begins when you enter the hospital and ends 60 days after you leave). In 2024, that deductible is $1,632, though this amount changes each year. After you meet the deductible, you pay nothing for the first 60 days of a hospital stay. Days 61 through 90 cost a daily copayment, and days 91 and beyond cost a higher daily amount.
Part B has a yearly deductible (in 2024, $240) and then you typically pay 20 percent of the approved charge for most services after that. Your doctor or provider must accept Medicare assignment — meaning they agree to accept Medicare's approved amount as full payment — for this 20 percent rule to explore. If a provider does not accept assignment, you may owe more.
Both Part A and Part B have out-of-pocket limits that vary by plan type. Original Medicare does not have a yearly out-of-pocket maximum the way private insurance does, which means your costs can be unpredictable if you have a serious illness or injury.
What Part A and Part B Do Not Cover
Neither part covers dental care, vision care, or hearing aids — three services many older adults need. Long-term custodial care in a nursing home (care that is not skilled nursing) is not covered. Prescription drugs are not covered by Part A or Part B; that is Part D, a separate plan you add.
Routine foot care, most acupuncture, and cosmetic surgery are not covered. Travel outside the United States is generally not covered, except in limited circumstances near the U.S. border. If you want coverage for these services, you can add a Medigap supplemental plan or switch to a Medicare Advantage plan, which often includes dental and vision benefits.
When Part A and Part B Begin
Part A coverage typically starts automatically on the first day of the month you turn 65, as long as you are receiving Social Security benefits or have been receiving them. If you are not yet receiving Social Security, you must sign up for Part A during your initial enrollment window — the three months before the month you turn 65, the month you turn 65, and the three months after.
Part B does not start automatically. You must sign up during your initial enrollment window or during the General Enrollment Period (January 1 through March 31 each year). If you miss your initial window and do not have other may have access to coverage, you will pay a late enrollment penalty for as long as you have Part B.
Original Medicare Versus Medicare Advantage
Original Medicare — Part A and Part B together — is the traditional government plan. You can see any doctor or hospital that accepts Medicare, and you pay the costs outlined above. Many people add a Medigap plan to cover the deductibles and copayments that Original Medicare does not pay.
Medicare Advantage is an alternative: a private insurance plan that includes Part A and Part B coverage (and usually Part D prescription drug coverage and sometimes dental or vision). With Medicare Advantage, you typically pay lower monthly premiums and have an out-of-pocket maximum, but you must use doctors and hospitals in the plan's network. The trade-off is predictability: you know your maximum yearly cost, but you have less freedom to choose providers.
Frequently Asked Questions
Do I have to pay a monthly premium for Part A?
Most people do not pay a monthly premium for Part A if they or their spouse paid Medicare taxes while working for at least 10 years. If you do not meet that requirement, you can still enroll in Part A but will pay a monthly premium, which varies based on your work history.
What happens if I go to a doctor who does not accept Medicare?
If a doctor does not accept Medicare at all, Medicare will not pay anything, and you will owe the full bill. Some doctors accept Medicare assignment (agree to the Medicare-approved amount); others do not. Before your visit, ask the office whether the doctor accepts Medicare and whether they accept assignment.
Can Part A and Part B cover the same service?
Sometimes. For example, if you have surgery in a hospital as an inpatient, Part A covers it. If you have the same surgery as outpatient (same-day), Part B covers it. The setting determines which part pays, not the service itself.
What is a benefit period under Part A?
A benefit period begins the day you enter a hospital and ends 60 days after you leave. If you are readmitted to the hospital more than 60 days later, a new benefit period starts and you pay a new deductible. This is different from a calendar year.
Do I need both Part A and Part B?
You do not have to enroll in Part B, but most people do because it covers essential services like doctor visits and preventive care. If you delay Part B enrollment without may have access to coverage, you will owe a late penalty. Part A is usually automatic, but you can decline it if you have other health coverage.