Medicare Part B covers outpatient medical services, doctor visits, preventive care, durable medical equipment, and certain prescription drugs. It’s the half of Original Medicare that handles everything outside of hospital inpatient stays (which fall under Part A). The standard monthly premium is $185.00 in 2025, with an annual deductible of $257. After you meet that deductible, you typically pay 20% of the Medicare-approved amount for most services.
Outpatient and Doctor Services
Part B covers two broad categories: medically necessary services and preventive services. Medically necessary means any service or supply that meets accepted standards of medical practice to diagnose or treat a condition. In practical terms, this includes office visits with your doctor, outpatient surgeries, diagnostic tests, X-rays, lab work, and second opinions before surgery.
Mental health care is fully included. Part B pays for individual and group psychotherapy, psychiatric evaluations, and partial hospitalization programs. You pay 20% of the Medicare-approved amount after your deductible, though hospital outpatient clinics may charge an additional copayment.
Ambulance services are covered when traveling by any other vehicle would endanger your health. Medicare pays for ground transport to the nearest appropriate facility. Air ambulance (helicopter or airplane) is covered when you need immediate transport that ground vehicles can’t provide. Non-emergency ambulance rides require a written order from your doctor confirming medical necessity.
Preventive Services at No Cost
Most preventive services cost you nothing out of pocket, as long as your provider accepts Medicare assignment. This is one of the most valuable parts of Part B, and the list is extensive:
- Cancer screenings: mammograms, colonoscopies, lung cancer screenings with low-dose CT, cervical and vaginal cancer screenings, prostate cancer screenings, and colorectal stool DNA tests
- Cardiovascular screenings: cholesterol and lipid panels, plus behavioral therapy for heart disease prevention
- Diabetes: screening tests, self-management training, the Medicare Diabetes Prevention Program, and medical nutrition therapy
- Vaccines: flu shots, COVID-19 vaccines, pneumococcal shots, and hepatitis B shots
- Other screenings: depression, HIV, hepatitis B and C, glaucoma, bone density, alcohol misuse, sexually transmitted infections, and abdominal aortic aneurysm
- Wellness visits: a one-time “Welcome to Medicare” preventive visit when you first enroll, plus a yearly wellness visit after that
Tobacco cessation counseling, obesity behavioral therapy, and HIV prevention medication (PrEP) are also covered at no cost.
Durable Medical Equipment
Part B covers medically necessary equipment prescribed by your doctor for use in your home. To qualify as durable medical equipment, an item must withstand repeated use, serve a medical purpose, be primarily useful to someone who is sick or injured, and be expected to last at least three years.
Covered equipment includes wheelchairs and scooters, hospital beds, walkers, canes, crutches, CPAP machines, oxygen equipment and accessories, infusion pumps, glucose monitors with test strips and lancets, and commode chairs. You pay 20% of the Medicare-approved amount after your deductible. One important detail: your supplier must be enrolled in Medicare. Always confirm this before ordering equipment, or you could end up paying the full cost yourself.
Prescription Drugs Under Part B
Part B doesn’t replace a Part D drug plan, but it does cover a specific category of medications: drugs you typically receive in a medical setting rather than picking up at a pharmacy. If a doctor or nurse administers an injection or infusion in an office or outpatient facility, Part B generally covers it.
Specific categories include injectable and infused chemotherapy drugs, certain oral cancer drugs (when an injectable version exists), osteoporosis injections, allergy treatments prepared by your provider, immunosuppressive drugs after a Medicare-covered organ transplant, blood clotting factors for hemophilia, and drugs delivered through durable medical equipment like nebulizers or infusion pumps. Part B also covers IV immune globulin given at home for primary immune deficiency, tube feeding and IV nutrition when you can’t absorb food normally, and oral anti-nausea drugs taken within 48 hours of chemotherapy.
What Part B Does Not Cover
Several common health expenses fall outside Part B entirely. The biggest gaps catch many people off guard:
- Routine dental care: cleanings, fillings, extractions, and dentures
- Vision: eye exams for prescription glasses and the glasses themselves
- Hearing aids and the exams needed to fit them
- Long-term care: nursing home stays that are custodial rather than skilled
- Cosmetic surgery
- Routine physical exams: Part B covers the annual wellness visit, but a traditional head-to-toe physical is not the same thing and isn’t covered
- Massage therapy
- Concierge or boutique medicine fees
Services from a doctor who has opted out of Medicare are also not covered, except in emergencies.
What Part B Costs in 2025 and 2026
The standard monthly premium for 2025 is $185.00, rising to $202.90 in 2026. The annual deductible is $257 in 2025 and $283 in 2026. After the deductible, you pay 20% of the Medicare-approved amount for most covered services, with no out-of-pocket maximum (which is why many people buy supplemental Medigap coverage).
Higher Premiums for Higher Earners
If your modified adjusted gross income exceeds certain thresholds, you pay more. Medicare uses your tax return from two years prior to determine your bracket. For 2025, individual filers earning $106,000 or less (or joint filers earning $212,000 or less) pay the standard $185.00. Above that, premiums rise in steps:
- $106,001 to $133,000 individual ($212,001 to $266,000 joint): $259.00/month
- $133,001 to $167,000 individual ($266,001 to $334,000 joint): $370.00/month
- $167,001 to $200,000 individual ($334,001 to $400,000 joint): $480.90/month
- $200,001 to $499,999 individual ($400,001 to $749,999 joint): $591.90/month
- $500,000 or more individual ($750,000 or more joint): $628.90/month
Late Enrollment Penalties
If you don’t sign up for Part B when you’re first eligible and you don’t qualify for a Special Enrollment Period (typically through employer coverage), you’ll face a permanent premium surcharge. The penalty is an extra 10% added to your monthly premium for every full 12-month period you delayed. Someone who waited two years, for example, would pay 20% more than the standard premium for as long as they have Part B. At 2026 rates, that turns a $202.90 monthly bill into roughly $243.48, every month, for life.