Part B covers doctor visits, outpatient hospital care, diagnostic tests, and preventive services

Part B is the medical insurance piece of Original Medicare. It pays for services you receive outside a hospital — mainly visits to doctors and specialists, lab work, imaging, physical therapy, and preventive screenings. Part B does not cover hospital stays (that is Part A), prescription drugs (that is Part D), or long-term care.

Part B is optional, but most people who have Part A enroll in it. You pay a monthly premium for Part B, and then Medicare covers 80 percent of approved services after you meet your annual deductible. You pay the remaining 20 percent, called coinsurance.

Key Takeaways

  • Part B covers doctor office visits, specialist consultations, lab tests, X-rays, ultrasounds, and other diagnostic imaging at any time.
  • Preventive services covered at no cost to you include annual wellness visits, cancer screenings, cardiovascular tests, and vaccinations.
  • Part B pays for outpatient hospital services such as emergency room visits, same-day surgery, and observation stays that do not result in admission.
  • You are responsible for the Part B deductible each year, then 20 percent coinsurance on most services; some preventive care has no cost-sharing.
  • Part B does not cover routine dental, vision, hearing aids, or prescription medications — those require separate coverage.

Doctor Visits and Specialist Care

Part B covers visits to your primary care doctor, cardiologists, orthopedists, neurologists, and any other physician or nurse practitioner you see for diagnosis and treatment. The visit itself is covered whether it happens in a doctor's office, an urgent care center, or a community health clinic. You pay your share of the cost after the deductible.

If your doctor refers you to a specialist, Part B covers that visit too. You do not need a referral from Medicare or your doctor to see a specialist — you can go directly to any doctor who accepts Medicare. However, some doctors do not accept Medicare assignment, meaning they may charge you more than Medicare's approved amount. Before your visit, ask the office whether the doctor accepts Medicare assignment.

Diagnostic Tests and Imaging

Part B covers blood tests, urinalysis, EKGs, and other lab work ordered by your doctor. It also covers imaging services: X-rays, CT scans, MRIs, ultrasounds, and PET scans when medically necessary. These services are covered whether they happen in a hospital outpatient department, an imaging center, or a doctor's office.

Part B does not cover routine screening tests that are not medically necessary — for example, a full-body CT scan for someone with no symptoms. However, certain screening tests are covered as preventive services at no cost to you, which is explained in the next section.

Preventive Services at No Cost

Medicare Part B covers a range of preventive services with no deductible and no coinsurance. These include an annual wellness visit with your doctor, during which you and your doctor review your health history and create a plan for staying healthy. You also receive a personalized prevention plan at no cost.

Screening tests covered at no cost include mammograms for breast cancer, colonoscopies and other colorectal cancer screenings, Pap tests for cervical cancer, prostate cancer screening, bone density scans, cardiovascular screening, diabetes screening, and abdominal aortic aneurysm screening. Vaccinations for influenza, pneumonia, and shingles are also covered at no cost. These preventive services must be ordered by your doctor and performed at a Medicare-approved facility.

Outpatient Hospital Services

Part B covers services you receive at a hospital without being admitted as an inpatient. This includes emergency room visits, urgent care at a hospital facility, same-day surgery, and observation stays. An observation stay is when you are monitored in a hospital bed but not formally admitted — Medicare still counts this as outpatient care under Part B.

Outpatient hospital services also include rehabilitation services, chemotherapy, dialysis, and mental health treatment provided in a hospital setting. You pay your coinsurance after meeting the deductible, just as you would for a doctor's office visit.

Durable Medical Equipment and Supplies

Part B covers durable medical equipment (DME) — items that can withstand repeated use and serve a medical purpose. This includes wheelchairs, walkers, canes, crutches, oxygen equipment, CPAP machines, hospital beds, and diabetic testing supplies. Your doctor must order the equipment, and it must be medically necessary.

You typically pay 20 percent coinsurance for DME after the deductible. Some items, such as diabetic testing supplies, may have different cost-sharing rules. DME must be obtained from a Medicare-approved supplier; using a non-approved supplier means you pay the full cost yourself.

What Part B Does Not Cover

Part B does not cover routine dental care, dentures, dental implants, or tooth extractions. Vision care such as eye exams for glasses or contact lenses, eyeglasses, and contact lenses are not covered, though Part B does cover eye exams related to medical conditions like glaucoma or cataracts. Hearing aids and hearing exams for the purpose of fitting hearing aids are not covered.

Part B also does not cover prescription medications — those are covered under Part D. Routine foot care, cosmetic surgery, and long-term care in a nursing home or assisted living facility are not covered. If you need any of these services, you may want to explore supplemental coverage (Medigap) or a Medicare Advantage plan, which may offer additional benefits.

Frequently Asked Questions

Do I have to pay anything for preventive services?

No. Preventive services such as annual wellness visits, cancer screenings, and vaccinations are covered at no cost when provided by a Medicare-approved provider. However, if your doctor finds a problem during a preventive visit and provides treatment, that treatment may have a cost-sharing amount.

What happens if my doctor does not accept Medicare assignment?

If your doctor does not accept assignment, they can charge up to 15 percent more than Medicare's approved amount. You are responsible for paying that extra amount out of pocket. Before scheduling, ask the office if the doctor accepts Medicare assignment to avoid surprise bills.

Is physical therapy covered under Part B?

Yes. Part B covers physical therapy, occupational therapy, and speech-language pathology when ordered by your doctor and medically necessary. These services are covered in outpatient settings such as clinics, hospitals, or your home. You pay coinsurance after the deductible.

Do I need to enroll in Part B, or is it automatic?

Part B is not automatic. You must enroll during your Initial Enrollment Period, which begins three months before the month you turn 65. If you delay enrollment without good reason, you may pay a higher premium for life. However, if you have employer coverage, you may be able to delay without penalty.

What is the difference between Part B coinsurance and the deductible?

The deductible is a fixed amount you pay each year before Medicare starts paying. Once you meet it, Medicare pays 80 percent of approved services and you pay 20 percent coinsurance. The deductible amount changes each year; the coinsurance is always 20 percent for most Part B services.