Medicare Part B covers doctor visits, outpatient hospital care, medical equipment, and preventive services

Medicare Part B is the medical insurance piece of Original Medicare. It pays for services from doctors, hospitals (when you are not admitted), labs, imaging, and equipment like wheelchairs or oxygen. Part B does not cover hospital stays — that is Part A — and it does not cover prescription drugs, dental, vision, or hearing aids.

Part B is optional, but most people who have Part A should enroll in Part B during their initial enrollment window. If you delay without a valid reason, you may face a permanent penalty on your premium. The standard monthly premium is deducted from your Social Security check (or paid directly if you do not yet collect).

You pay a yearly deductible before Part B starts paying, and then you pay 20 percent of the approved amount for most services. Some preventive services have no cost-sharing at all.

Key Takeaways

  • Part B covers doctor office visits, lab tests, X-rays, and outpatient surgery, but you pay 20 percent of the Medicare-approved cost after your deductible.
  • Preventive services like annual wellness visits, cancer screenings, and vaccines are covered at no cost to you when you see an in-network provider.
  • Part B does not cover dental work, vision exams, hearing aids, or prescription drugs — you need separate coverage or pay out of pocket for those.
  • If you delay enrolling in Part B without a valid reason, Medicare adds a permanent surcharge to your premium for as long as you have the coverage.

Doctor visits and office-based care

Part B pays for visits to your primary care doctor, specialists, and other healthcare providers who accept Medicare. This includes routine checkups, sick visits, and follow-up appointments. You pay 20 percent of the Medicare-approved amount after you have met your yearly deductible (the deductible amount changes each year).

The key word is "Medicare-approved." If your doctor does not accept Medicare assignment, you may owe more than 20 percent. A doctor who accepts assignment agrees to charge only what Medicare allows. Before your visit, ask the office whether they accept Medicare assignment — most do, but not all.

Part B also covers telehealth visits with doctors and nurse practitioners, under the same cost-sharing rules as in-person visits. You do not need to be homebound to use telehealth; it is available to anyone with Part B.

Hospital outpatient services and emergency care

Part B covers care you receive at a hospital outpatient department — meaning you go to the hospital but are not admitted as an inpatient. This includes emergency room visits, observation stays, outpatient surgery, and diagnostic procedures done at the hospital.

You pay 20 percent of the Medicare-approved amount for most outpatient hospital services, after your deductible. However, some services (like certain preventive screenings) may have different cost-sharing or no cost at all.

If you arrive at the emergency room and are later admitted to the hospital as an inpatient, Part A takes over and covers your hospital stay. Part B still covers the emergency room visit itself, but the hospital stay is a separate bill under Part A rules.

Diagnostic tests, imaging, and lab work

Part B covers blood tests, urinalysis, X-rays, CT scans, ultrasounds, and other imaging ordered by your doctor. It also covers electrocardiograms (EKGs), stress tests, and other diagnostic procedures done in a doctor's office or outpatient setting.

You pay 20 percent of the Medicare-approved amount after your deductible. Some preventive screening tests — such as mammograms, colonoscopies, and bone density scans — are covered at no cost when ordered for screening purposes (not diagnosis of a known condition).

If your doctor orders a test that Medicare considers not medically necessary, Medicare may deny the claim. Your doctor's office should know which tests Medicare covers, but if you are unsure, you can ask before the test is done.

Medical equipment and supplies

Part B covers durable medical equipment (DME) like wheelchairs, walkers, canes, oxygen equipment, CPAP machines, and hospital beds. It also covers diabetic supplies (test strips, lancets, syringes) and other medically necessary items your doctor prescribes.

You typically pay 20 percent of the Medicare-approved amount after your deductible. However, some items have rental or purchase limits — for example, Medicare may cover a wheelchair rental for a set period before requiring you to purchase one instead.

Your doctor must write a prescription or order for the equipment, and you must obtain it from a Medicare-enrolled supplier. If you buy from a non-enrolled supplier, Medicare will not pay.

Preventive services at no cost

Part B covers a range of preventive services with no deductible and no coinsurance when you see a provider who accepts Medicare assignment. These include an annual wellness visit (a comprehensive health assessment), cancer screenings (mammogram, colonoscopy, Pap test), cardiovascular screening, diabetes screening, bone density testing, and vaccines (flu, pneumonia, shingles, COVID-19).

The catch: these services must be ordered for prevention, not for diagnosis or treatment of a known condition. For example, a colonoscopy for screening is free; a colonoscopy to investigate bleeding is not. Your doctor's office should know the difference, but it is worth confirming.

Part B also covers certain mental health services, including therapy and psychiatric visits, at no cost for preventive mental health screening.

What Part B does not cover

Part B does not cover prescription drugs (you need Part D for that), dental work, routine vision exams, eyeglasses, hearing aids, or routine hearing exams. It does not cover long-term care, custodial care in a nursing home, or most services outside the United States.

Part B also does not cover cosmetic surgery, weight loss surgery (unless medically necessary for a documented condition), or experimental treatments not yet approved by the FDA. Acupuncture, chiropractic care, and massage therapy are not covered, though some limited acupuncture coverage began in 2020 for chronic lower back pain.

If you need coverage for these services, you can buy a Medigap (supplemental insurance) plan, enroll in a Medicare Advantage plan, or pay out of pocket.

How much Part B costs

The standard monthly premium for Part B varies by year and by income. Higher-income beneficiaries pay more through Income-Related Monthly Adjustment Amounts (IRMAA). The yearly deductible also changes annually.

Beyond the premium and deductible, you pay 20 percent coinsurance for most services. If you see an out-of-network provider or one who does not accept assignment, you may owe more. Medigap plans can cover some or all of these out-of-pocket costs, but Medigap is a separate purchase.

If you delay enrolling in Part B without a valid reason (such as active employer coverage), you will pay a permanent surcharge of 10 percent per year of delay, added to your premium for life.

Frequently Asked Questions

Do I have to enroll in Part B when I turn 65?

No, but you should unless you have active employer health coverage. If you delay without a valid reason, you will pay a permanent penalty. Your initial enrollment window is three months before and three months after the month you turn 65, plus the month itself.

What if my doctor does not accept Medicare?

You can still see them, but you will likely owe more than 20 percent. Ask your doctor's office whether they accept Medicare assignment before your visit. If they do not, ask what they charge and whether they will file the claim with Medicare for you.

Are preventive services really free?

Yes, when ordered for prevention and when you see a provider who accepts Medicare assignment. If the same service is ordered to diagnose or treat a known condition, you will owe coinsurance. Your doctor should tell you which category applies.

Does Part B cover physical therapy?

Yes, when ordered by your doctor for a medical condition. You pay 20 percent of the Medicare-approved amount after your deductible. There are visit limits in some cases, so ask your therapist's office about Medicare's rules for your condition.

What happens if Medicare denies a claim?

Your doctor's office or the provider should send you a notice explaining why. You have the right to appeal. Contact your provider's billing office or call Medicare at 1-800-MEDICARE to ask about the denial and your appeal options.