Medicare Part B is the outpatient half of Original Medicare. While Part A handles your hospital stays, Part B covers the day-to-day medical care most of us actually use more often -- doctor visits, lab work, preventive care, and medical equipment.

Understanding exactly what Part B does and does not cover can save you from unexpected bills and help you figure out whether you need additional coverage.

What Part B Covers

The coverage falls into two broad categories: medically necessary services and preventive services.

Medically Necessary Services

These are services your doctor orders because they are needed to diagnose or treat a condition. Part B covers a wide range here.

Doctor visits. This includes visits to your primary care physician, specialists, and nurse practitioners, whether in the office, at a clinic, or through telehealth. Part B pays 80% of the Medicare-approved amount after your annual deductible, and you pay the other 20%.

Outpatient hospital care. If you visit an emergency room and are not formally admitted, or if you have a procedure in an outpatient surgery center, Part B picks that up rather than Part A.

Lab and diagnostic tests. Blood work, urine tests, X-rays, MRIs, CT scans, and other imaging are all covered under Part B when ordered by your doctor.

Mental health care. Part B covers outpatient mental health services including visits to psychiatrists, psychologists, and licensed clinical social workers. It also covers opioid treatment programs.

Physical, occupational, and speech therapy. All three are covered when medically necessary, though there are some limits on ongoing therapy that are worth checking with your provider.

Ambulance services. Ground ambulance is covered when other transportation would endanger your health. Air ambulance is covered in specific circumstances.

Durable medical equipment. Wheelchairs, walkers, CPAP machines, home oxygen equipment, hospital beds for home use, and blood sugar monitors are all covered when prescribed by a doctor.

Home health care. If you are homebound and your doctor certifies that you need skilled nursing or therapy services, Part B (and sometimes Part A) covers those visits.

Preventive Services

Part B covers a substantial list of preventive screenings and counseling, many of them at no cost to you when you see a Medicare-accepting provider.

Important: To get preventive services at no cost, your doctor must bill them as preventive. If your doctor addresses a new medical problem during a preventive visit, that portion may be billed as a regular office visit, which would trigger the 20% coinsurance.

What Part B Does NOT Cover

There are some notable gaps that trip people up.

Prescription drugs. Outpatient prescription drugs you take at home are not covered by Part B. You need a separate Part D plan for that. (Some drugs administered in a doctor's office, like chemotherapy, are covered under Part B -- but your everyday medications are not.)

Dental care. Routine dental exams, cleanings, fillings, and dentures are not covered. Medicare Advantage plans sometimes include basic dental, or you can buy a standalone dental plan.

Vision care. Routine eye exams for glasses or contact lenses are not covered. Neither are the glasses or contacts themselves. Part B does cover glaucoma screenings for high-risk patients and cataract surgery.

Hearing aids and exams. Routine hearing tests and hearing aids are not covered under Original Medicare.

Cosmetic procedures. Anything considered elective or cosmetic is not covered.

Acupuncture. Medicare recently began covering acupuncture for chronic low back pain specifically, but most other acupuncture is not covered.

How Much Does Part B Cost in 2026

The standard monthly premium for Part B in 2026 is approximately $185 per month. However, if your income is above a certain threshold, you will pay more through what is called the Income-Related Monthly Adjustment Amount (IRMAA). Single filers earning over $103,000 and couples earning over $206,000 will see higher premiums on a sliding scale.

The annual Part B deductible in 2026 is around $250. After you meet that, you pay 20% of the Medicare-approved amount for most covered services. That 20% has no annual cap under Original Medicare alone, which is why many people choose a Medigap supplemental plan.

Bottom Line

Part B is comprehensive for outpatient care but has real gaps in dental, vision, hearing, and prescription drugs. Understanding those gaps early helps you build a coverage strategy that does not leave you with surprise bills.

Disclaimer: The information on this site is for educational purposes only and does not constitute legal, financial, or medical advice. Medicare rules and costs change annually. Always verify current information at Medicare.gov or by calling 1-800-MEDICARE. Consider consulting a licensed insurance professional or your State Health Insurance Assistance Program (SHIP) for personalized guidance.