Medicare Part B in Practice: What It Covers at the Doctor's Office and What You Pay

What Part B covers

Medicare.gov's overview of the parts of Medicare says Part B helps cover services from doctors and other health care providers, outpatient care, home health care, durable medical equipment such as wheelchairs, walkers and hospital beds, and many preventive services such as screenings, vaccines and yearly Wellness visits. Part A covers inpatient hospital care, and Part D helps cover the cost of prescription drugs.

Medicare.gov's page on what Part B covers groups this into two types of services:

• Medically necessary services: services or supplies that meet accepted standards of medical practice to diagnose or treat your condition.
• Preventive services: care to prevent illness or find it early, when treatment is likely to work best.

The same page lists examples such as ambulance services, clinical research, durable medical equipment, limited outpatient prescription drugs, mental health and substance use disorder services, and oxygen equipment. If you are in a Medicare Advantage plan, your plan may have different rules, but it must give you at least the same coverage as Original Medicare.

Who counts as a "doctor" under Part B

Medicare.gov's page on doctor and other health care provider services says Part B covers medically necessary services from a Doctor of Medicine (MD) or Doctor of Osteopathic Medicine (DO) and, in some cases, a podiatrist, optometrist or chiropractor. It also covers services from other providers, including nurse practitioners, physician assistants, clinical nurse specialists, clinical psychologists, clinical social workers, marriage and family therapists, mental health counselors, and physical, occupational and speech-language therapists.

What you pay

The monthly premium

CMS published the 2026 amounts in its fact sheet on 2026 Part A and B premiums and deductibles. The standard monthly Part B premium is $202.90 in 2026, up from $185.00 in 2025. People with higher incomes pay more: the fact sheet says these income-related monthly adjustment amounts affect roughly 8% of people with Part B, starting with individual tax returns above $109,000 or joint returns above $218,000. CMS released the 2026 amounts on November 14, 2025; amounts for 2027 are set separately, so check Medicare.gov when they are published.

The yearly deductible

The Part B deductible is $283 in 2026, up from $257 in 2025. You pay it once a year before Original Medicare starts to pay for most Part B services.

Coinsurance

After the deductible, Medicare.gov's costs page says you usually pay 20% of the cost for each Medicare-covered service. The 20% is figured on the Medicare-approved amount, not on what the office lists as its charge. Medicare.gov's comparison of Original Medicare and Medicare Advantage notes that Original Medicare has no yearly limit on what you pay out of pocket unless you have supplemental coverage such as Medigap, while Medicare Advantage plans have a yearly limit.

What changes the amount you owe

The doctor services page lists what your amount depends on: other insurance you may have, how much your doctor charges, whether your doctor accepts assignment, the type of facility, and where you get the test, item or service.

Preventive services with no cost-sharing

Medicare.gov's preventive services page lists the screenings, vaccines and counseling Part B covers. For most of them you pay nothing if the provider accepts assignment, and the Part B deductible does not apply.

"Welcome to Medicare" and the yearly Wellness visit

Two visits often cause confusion:

• "Welcome to Medicare" preventive visit: Medicare.gov's page on this visit describes a one-time review of your medical and social history, screenings and vaccines you need, a simple vision test and a written prevention plan, available within the first 12 months you have Part B. It is not a comprehensive physical exam.
• Yearly "Wellness" visit: Medicare.gov's Wellness visit page describes a conversation-based visit once every 12 months to create or update a prevention plan, including a health risk questionnaire and a cognitive assessment. It is not a routine physical exam either, and your first one cannot take place within 12 months of your Part B enrollment or your "Welcome to Medicare" visit.

When a free visit turns into a bill

Both pages warn that you may have to pay coinsurance, and the deductible may apply, if the provider performs additional tests or services during the same visit that Medicare does not cover under the preventive benefit. If Medicare does not cover them at all, such as a routine physical exam, you may have to pay the full amount. The Wellness visit page suggests scheduling a separate appointment for specific health concerns so the Wellness visit stays focused on prevention. It is reasonable to ask the office before the visit what will be billed as preventive and what will not.

Assignment and the limiting charge

Whether a provider accepts assignment has a direct effect on your Part B bill. Medicare.gov's assignment page explains:

• A provider who accepts assignment agrees to the Medicare-approved amount as full payment, charges you only the deductible and coinsurance, and submits the claim to Medicare.
• A non-participating provider may accept assignment case by case. When they do not, you might have to pay the full amount at the time of service, and in many cases they can charge up to 15% above the Medicare-approved amount. That cap is the limiting charge.
• A provider who opted out of Medicare is not paid by Medicare at all, except in emergencies, and you pay under a private contract.

The same page notes that most doctors, providers and suppliers accept assignment, but that you should always check. Our Medicare assignment guide goes into the details.

Before a test or procedure

The doctor services page advises asking how much a test, item or service will cost, because a doctor may recommend services that Medicare does not cover or covers less often. Practical questions:

• Do you accept assignment for my visit and this test?
• Is this service covered by Medicare, and how often?
• Where will it be done? The type of facility and the place of service change what you owe.

The doctor services page also notes that if you have not had services from a doctor or group practice in the last 3 years, they may consider you a new patient, and that you should check with the practice whether it is accepting new patients.

How Part B data on T-MedInfo relate to your bill

Many clinician profiles on this site include a Medicare Part B section built from CMS's public data on services billed to Original Medicare. For each year we have loaded it shows the service codes a clinician billed, how many services and patients, the average submitted charge and the average Medicare allowed amount. Profiles also show whether CMS lists the clinician as accepting assignment.

These figures are useful background, with limits that CMS states in its methodology: they cover Original Medicare claims only, leave out services provided to 10 or fewer patients, and describe a past year. The allowed amount is an average across many claims, so it is not a quote for your visit, and your 20% depends on the exact codes billed, the setting and whether you have met your deductible. Our guide to Part B charges and allowed amounts walks through the arithmetic, and our methodology page explains how we load the data.

Where to get help

For questions about your own claims or coverage, call 1-800-MEDICARE (1-800-633-4227) or contact your State Health Insurance Assistance Program (SHIP) for free counseling.