The basic split: Hospital care versus doctor visits

Medicare Part A covers inpatient hospital stays, skilled nursing facility care after a hospital stay, hospice care, and some home health services. Medicare Part B covers doctor visits, outpatient care, lab tests, imaging, and medical equipment like wheelchairs or oxygen. Part A is automatic when you turn 65 if you have worked and paid Medicare taxes. Part B requires you to sign up, and most people pay a monthly premium for it.

The two parts work together but cover different settings. Part A pays for care when you are admitted to a hospital bed. Part B pays for care you receive as an outpatient — meaning you go to an office or clinic and go home the same day. Understanding which part covers what matters because your out-of-pocket costs differ between them, and some services require both parts to be covered.

Key Takeaways

  • Part A covers hospital stays, skilled nursing care after hospitalization, hospice, and some home health visits; Part B covers doctor appointments, outpatient procedures, lab work, and medical equipment.
  • Part A has a deductible per hospital stay and no monthly premium; Part B has a monthly premium and a yearly deductible, with you paying 20 percent of most services after the deductible.
  • You are automatically enrolled in Part A at 65 if you have paid Medicare taxes, but you must actively sign up for Part B during your enrollment window or face a permanent penalty.
  • Neither part covers dental, vision, hearing aids, or long-term custodial care in a nursing home, though you can buy supplemental coverage for some of these gaps.
  • Some services require both parts — for example, a doctor must order home health care for Part A to cover it, and the doctor visit itself is covered by Part B.

What Part A covers in detail

Part A covers a hospital stay from the moment you are admitted as an inpatient through discharge. This includes your room, meals, nursing care, medications given in the hospital, and basic lab work and imaging done during your stay. If you need surgery while hospitalized, Part A covers the operating room and surgical supplies. You pay a deductible for each benefit period (the first 60 days of a hospital stay), which changes yearly. After you pay the deductible, Medicare covers all costs for days 1 through 60. Days 61 through 90 require a daily copay from you. Beyond 90 days, you can use lifetime reserve days, which also have a daily copay.

Part A also covers skilled nursing facility care — a facility that provides medical care and rehabilitation, not just custodial help. You must have been hospitalized for at least three days before Part A will cover a nursing facility stay. Part A covers the first 20 days fully, days 21 through 100 with a daily copay from you, and nothing after day 100 in a benefit period. This is different from a regular nursing home that provides only personal care; Part A does not cover that type of long-term custodial care.

Hospice care is covered by Part A when a doctor certifies you have six months or less to live. Part A covers doctor visits, nursing care, medications related to your terminal condition, medical equipment, and counseling. You pay nothing for hospice services except a small copay on medications and inpatient respite care. Part A also covers some home health services — skilled nursing visits, physical therapy, occupational therapy, and speech therapy — when ordered by your doctor and provided by a Medicare-certified agency. You pay nothing for home health if Part A covers it, though you may pay 20 percent of the cost of medical equipment.

What Part B covers in detail

Part B covers doctor visits, whether in an office, clinic, or hospital outpatient department. This includes annual wellness visits, sick visits, specialist consultations, and preventive care like cancer screenings and vaccinations. Part B also covers outpatient surgery and procedures — for example, a cataract removal done at an ambulatory surgery center where you go home the same day. Lab work ordered by your doctor, imaging like X-rays and ultrasounds, and pathology services are covered by Part B when done in an outpatient setting.

Part B covers durable medical equipment — devices you use at home that are ordered by a doctor, such as a wheelchair, walker, oxygen equipment, diabetic supplies, or a hospital bed. You typically pay 20 percent of the approved amount after you meet your yearly Part B deductible. Part B also covers mental health services, including therapy and psychiatric visits, at the same 20 percent copay after your deductible. Physical therapy, occupational therapy, and speech therapy are covered by Part B when done in an outpatient setting or ordered by a doctor for home care.

Preventive services covered by Part B with no copay include an annual wellness visit, screenings for cancer, heart disease, and diabetes, bone density testing, and vaccines like flu and pneumonia shots. Part B also covers some services that might surprise you: it covers a one-time welcome visit to establish care with a new primary doctor, and it covers certain medications given in a doctor's office or outpatient clinic as part of treatment — though not medications you pick up at a pharmacy.

What neither part covers

Medicare Part A and Part B do not cover dental care, including cleanings, fillings, root canals, or dentures. They do not cover routine vision care, eyeglasses, or contact lenses, though Part B does cover one pair of glasses or contact lenses after cataract surgery. Hearing aids and hearing exams are not covered, though some preventive hearing screening may be covered. Long-term custodial care in a nursing home — care that helps you with daily activities but is not medical — is not covered by either part.

Cosmetic surgery is not covered unless it is medically necessary after an injury or illness. Over-the-counter medications are not covered. Certain treatments considered experimental or not medically necessary are not covered. Travel outside the United States is generally not covered by Parts A and B, though some exceptions exist for Canada and Mexico if you are traveling from the United States.

How costs work under Part A and Part B

Part A has no monthly premium if you have paid Medicare taxes for at least 10 years. You pay a deductible per benefit period (a hospital stay or skilled nursing stay), which is set yearly by Medicare. In 2024, the Part A deductible is $1,632 per benefit period, though this amount changes annually. After you pay the deductible, you pay nothing for days 1 through 60 of a hospital stay. Days 61 through 90 cost you a daily amount (in 2024, $408 per day). Skilled nursing facility care costs you nothing for days 1 through 20, then a daily copay for days 21 through 100.

Part B requires a monthly premium, which varies based on your income. In 2024, the standard premium is $164.90 per month for most people, but higher earners pay more. You also pay a yearly deductible (in 2024, $240), and after you meet it, you pay 20 percent of the approved amount for most services. Some preventive services have no copay even before you meet your deductible. If you see a doctor who does not accept Medicare assignment, you may pay more than 20 percent.

The costs described here are for 2024 and change yearly. Your actual costs depend on whether you have supplemental coverage, whether your doctor accepts Medicare assignment, and your income level for Part B premiums.

When you need both parts working together

Some services require both Part A and Part B to be fully covered. Home health care is a common example: Part A covers the skilled nursing visits and therapy, but only if a doctor has ordered them and you meet Part A's requirements. The doctor visit where the order is written is covered by Part B. If you have only Part A and not Part B, you would have to pay out of pocket for the doctor visit that triggers the home health coverage.

Inpatient rehabilitation after a hospital stay is another example. Part A covers the facility stay, but the doctor who oversees your care bills Part B. If you lack Part B, you would owe the doctor's bill yourself. This is why having both parts is important: one part alone leaves gaps that can become expensive.

Supplemental and alternative coverage options

Because Parts A and B do not cover everything and require you to pay deductibles and copays, many people buy Medigap (supplemental insurance) to cover some of those out-of-pocket costs. Medigap plans are sold by private insurance companies and help pay your Part A and Part B deductibles, copays, and coinsurance. Different Medigap plans cover different amounts; some cover most of your copays, while others cover less.

Alternatively, some people choose Medicare Advantage (Part C), which is an all-in-one plan sold by private insurance companies that includes Part A, Part B, and usually prescription drug coverage. Medicare Advantage plans often have lower premiums than Part B plus Medigap, but they typically have higher copays and may limit which doctors you can see. You cannot have both Medigap and Medicare Advantage at the same time.

Frequently Asked Questions

Do I have to sign up for Part B, or is it automatic like Part A?

Part B is not automatic. You must sign up during your initial enrollment period (the three months before and after you turn 65) or during the general enrollment period (January 1 through March 31 each year). If you delay signing up without a valid reason, you may face a permanent penalty on your monthly premium for as long as you have Part B.

What happens if I go to the hospital but am not admitted as an inpatient?

If you are in the hospital but kept as an outpatient (sometimes called "observation status"), Part B covers the care, not Part A. You will pay Part B copays and coinsurance rather than the Part A deductible. This distinction matters because observation status can result in higher out-of-pocket costs. Ask the hospital to clarify your status if you are unsure.

Does Part B cover my prescriptions?

Part B does not cover medications you pick up at a pharmacy. Prescription drug coverage is Part D, which you buy separately. Part B covers only medications given to you in a doctor's office or hospital outpatient setting as part of a treatment or procedure.

Can I use my Part A and Part B coverage outside the United States?

Generally, no. Medicare covers care only in the United States, except for limited situations in Canada and Mexico when you are traveling from the United States. If you travel internationally, you may want to buy travel health insurance for the duration of your trip.

What should I ask my doctor about Part A and Part B coverage?

Ask whether a recommended service or procedure is covered by Part A or Part B, what your out-of-pocket cost will be, and whether the doctor accepts Medicare assignment. If you are being admitted to the hospital, ask whether you will be admitted as an inpatient (Part A) or kept as an outpatient (Part B), because the cost difference is significant.