Part A covers hospital stays, skilled nursing, hospice, and some home health care

Medicare Part A is hospital insurance. It pays for inpatient hospital care — meaning you stay overnight — plus skilled nursing facilities, hospice care, and limited home health services. You do not pay a monthly premium for Part A if you or your spouse paid Medicare taxes for at least 10 years while working. Most people age 65 and older have Part A automatically.

Part A covers the full cost of the first three days in a hospital, minus a deductible (which changes each year). After three days, you pay a daily coinsurance amount for days 4 through 60. Days 61 and beyond cost more per day, and Part A stops covering after 90 days in a single hospital stay. If you need a skilled nursing facility after a hospital stay of at least three days, Part A covers the first 20 days completely, then charges a daily coinsurance for days 21 through 100.

Hospice care — end-of-life comfort care — is covered by Part A with minimal out-of-pocket costs. Home health care is covered only if a doctor orders it, you are homebound, and you need skilled care like wound dressing or physical therapy. Routine home care, cleaning, or meal delivery are not covered.

Part B covers doctor visits, outpatient care, tests, and medical equipment

Medicare Part B is medical insurance. It pays for doctor office visits, outpatient hospital services, diagnostic tests, lab work, X-rays, physical therapy, mental health care, and durable medical equipment like wheelchairs and oxygen. You pay a monthly premium for Part B (the amount depends on your income), plus you pay 20 percent of the cost after you meet your annual deductible.

Part B covers preventive care with no cost to you — annual wellness visits, cancer screenings, vaccinations, and cardiovascular screenings are all free. Once you need treatment rather than prevention, the 20 percent coinsurance kicks in. If your doctor charges more than Medicare allows, you may owe the difference, unless your doctor has agreed to accept Medicare's approved amount as full payment.

Part B does not cover routine dental care, eye exams for glasses or contacts, hearing aids, or long-term custodial care in a nursing home. It also does not cover most prescription drugs — that is Part D's role.

Key Takeaways

  • Part A covers hospital stays, skilled nursing facilities, and hospice; most people do not pay a monthly premium for it.
  • Part B covers doctor visits, outpatient care, tests, and equipment; you pay a monthly premium and 20 percent coinsurance after your deductible.
  • Part A has daily coinsurance costs after the first three hospital days and stops covering after 90 days in a single stay.
  • Part B preventive care is free, but treatment services require you to pay 20 percent of the approved cost.
  • Neither Part A nor Part B covers dental, vision, hearing aids, or prescription drugs (except those given in a hospital or nursing facility).

What you pay out of pocket with Part A and Part B

Part A has an annual deductible you pay once per benefit period (a benefit period starts when you enter the hospital and ends 60 days after you leave). After that deductible, you pay nothing for the first three days, then a daily coinsurance amount for days 4 through 60. The daily coinsurance is roughly one-quarter of the deductible amount. For skilled nursing, you pay nothing for days 1 through 20, then a daily coinsurance for days 21 through 100.

Part B requires you to pay a monthly premium (higher if your income is above a certain threshold), an annual deductible, and then 20 percent of the approved cost for most services. Some services like mental health visits have different coinsurance amounts. If you see a doctor who does not accept Medicare, you may owe the full bill — Medicare will not pay anything.

The deductible and coinsurance amounts change each year. You can find the current amounts on Medicare.gov or by calling 1-800-MEDICARE.

The gap between Part A and Part B coverage

Part A and Part B together do not cover everything. Prescription drugs are covered only if you are in a hospital or skilled nursing facility; otherwise, you need Part D (prescription drug coverage). Dental, vision, and hearing are not covered by either part. Long-term care in a nursing home — meaning custodial care where you need help with daily activities but not skilled medical care — is not covered.

Many people buy a Medigap policy (also called supplemental insurance) to cover the gaps: the deductibles, coinsurance, and costs when a doctor charges more than Medicare allows. Others enroll in a Medicare Advantage plan (Part C), which is an alternative to Part A and Part B offered by private insurers. Medicare Advantage often includes prescription drug coverage and dental or vision benefits, but usually requires you to use doctors in a specific network.

If your income is very low, you may be able to get help paying Part B premiums and coinsurance through Medicaid or a Medicare Savings Program run by your state.

Preventive services covered at no cost

Part B covers many preventive services with zero coinsurance and zero deductible. These include an annual wellness visit with your doctor, colorectal cancer screening, mammograms, Pap tests, prostate cancer screening, cardiovascular screening, diabetes screening, bone density screening, and vaccinations (flu, pneumonia, shingles, COVID-19). You pay nothing for these services if your doctor accepts Medicare assignment.

Preventive care is one of the best values in Medicare. If you have not had your annual wellness visit, you can schedule one with any doctor who accepts Medicare. The visit includes a review of your health history, current medications, and risk factors, and it is a good time to discuss any concerns before they become costly problems.

When Part A or Part B might not pay

Part A will not pay for a hospital stay if you are admitted for observation rather than as an inpatient. This distinction matters: observation status means you are being monitored but not formally admitted, so Part A does not cover it — Part B does, but with higher coinsurance. Ask the hospital whether you are being admitted as an inpatient or placed on observation status.

Part B will not pay if you see a doctor who does not accept Medicare or if you receive care outside the United States (except in limited circumstances in Canada, Mexico, or US territories). Part B also will not pay for cosmetic surgery, most dental work, routine foot care, or hearing aids. If a service is not on Medicare's list of covered services, you pay the full cost yourself.

If you disagree with a denial, you have the right to file an appeal. Contact your doctor's office or the provider who denied the claim to understand why it was denied, then follow the appeal process outlined in the denial letter.

Frequently Asked Questions

Do I have to enroll in Part B, or can I just use Part A?

You can have Part A without Part B, but most people need both. Part A alone covers only hospital and skilled nursing care. If you delay enrolling in Part B without good reason, you may pay a permanent penalty on your premium. You have a seven-month window around your 65th birthday to enroll without penalty.

What happens if I go to the emergency room but am not admitted to the hospital?

If you are treated in the ER and sent home, Part B covers the visit (you pay 20 percent coinsurance after your deductible). If you are admitted to the hospital as an inpatient, Part A covers it. If you are placed on observation status, Part B covers it at a higher coinsurance rate.

Does Part A or Part B cover prescription drugs?

No, unless you are in a hospital or skilled nursing facility, where medications are included in the facility's charge. For drugs you take at home, you need Part D (prescription drug coverage) or a Medicare Advantage plan that includes drug coverage. You can enroll in Part D during the annual enrollment period or when you first turn 65.

What if my doctor charges more than Medicare allows?

If your doctor accepts Medicare assignment, they agree to charge only what Medicare approves, and you owe 20 percent of that approved amount. If your doctor does not accept assignment, they can charge up to 15 percent more than the approved amount, and you owe that difference on top of your coinsurance.

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

Yes, any provider that accepts Medicare can treat you under Part A or Part B. You do not need to choose a specific network or get referrals. However, if you enroll in a Medicare Advantage plan instead of staying on Original Medicare (Part A and B), you may be limited to in-network providers.