What is Medicare Part B?

En español | Part B is one of Medicare’s four main parts.

Part B covers doctors’ services, diagnostic screenings, lab tests, preventive services, outpatient care, plus some medical equipment, and transportation.

Part A helps pay for inpatient stays in hospitals and skilled nursing facilities, some home care and end-of-life hospice care. Together, Part A and Part B are known as original Medicare.

Part C, also known as Medicare Advantage, is a private health insurance alternative to federally run original Medicare. You still need to sign up for Medicare parts A and B if you choose to get coverage from a Medicare Advantage plan.

Part D is prescription drug coverage, which you can get through a stand-alone policy or from a Medicare Advantage plan.

What services does Medicare Part B cover?

The following services are included:

• Doctor visits or appointments with other health care providers, including some doctor services when hospitalized.
• Diabetes care, including education, certain equipment, prevention programs and screenings.
• Diagnostic tests including CT scans, electrocardiograms, MRIs and X-rays.
• Durable medical equipment, such as wheelchairs and walkers, that your doctor prescribes for use in your home.
• Emergency department and outpatient surgery center services, as well as other outpatient hospital services.
• Some health programs, such as cardiac rehabilitation, obesity counseling and smoking cessation.
• Laboratory services, such as blood and urine tests.
• A limited number of prescription drugs that you usually don’t administer yourself, such as insulin from an external insulin pump that’s not disposable. However, insulin you administer yourself is covered under Medicare Part D instead.
• Outpatient mental health services.
• Outpatient physical therapy, occupational therapy and speech and language pathology services.
• Preventive care, such as flu shots and mammograms, to help avert illness or detect it at an early stage. Many preventive services are covered without deductibles or copayments. However, some vaccinations, such as the shingles vaccine, are covered under Part D instead.
• A Welcome to Medicare checkup and the annual wellness visit, which are covered in full without deductibles or copayments, unless additional tests are ordered. 

Even though Part B covers many doctor services, it doesn’t cover everything. Part B generally doesn’t cover routine dental, hearing and vision care.

Care not considered medically necessary, such as elective cosmetic surgery, isn’t covered, and chiropractor and acupuncture visits are paid for only if you meet very specific criteria. Additionally, Part B doesn’t cover medical services outside the United States, except in rare circumstances.

How much does Medicare Part B cost?

Even though Medicare Part B covers many of your expenses for doctor services and outpatient care, you will still have some out-of-pocket costs.

Part B premiums. Most people pay $164.90 a month in 2023 for Medicare Part B premiums. People who are single with an adjusted gross income of more than $97,000 or married filing jointly with income greater than $194,000 pay a high-income surcharge with premiums ranging from $230.80 to $560.50 a month, depending on income level.

If you don’t enroll in Medicare when you are first eligible or qualify for a special enrollment period to sign up later, you also may have to pay a late-enrollment penalty, which is added to your Part B premiums for as long as you have the coverage.

Deductible. You must pay a $226 deductible in 2023 before most Part B coverage begins. However, the Welcome to Medicare checkup, the annual wellness visit and some preventive care are not subject to any deductible or coinsurance unless your doctor orders additional tests. 

Coinsurance. After paying the deductible, you generally pay 20 percent of the Medicare-approved amount for most doctor and outpatient services and for durable medical equipment.

Extra charges from doctors who don’t “accept assignment.” Most doctors accept assignment, which means that they agree to take the amount Medicare approves for their services. Doctors who don’t accept assignment can charge up to 15 percent above the Medicare-approved amount for a service, which you would have to pay in addition to the 20 percent copayment for doctor services.

Keep in mind

Want Medicare Advantage? If you choose to get coverage through a private Medicare Advantage plan rather than original Medicare, you still must enroll in Medicare Part A and Part B.

The Medicare Advantage plan must provide as least as much coverage as original Medicare, but you may have different out-of-pocket costs. For example, rather than the Part B deductible and 20 percent coinsurance, a Medicare Advantage plan may have no copayments for in-network primary doctor visits, a $20 copay for diagnostic tests and procedures, $40 copay for specialists and $90 copay for emergency care.  

You may be required to use in-network doctors and other providers to receive coverage from the Medicare Advantage plan. Or you may have to pay more if you use out-of-network services, depending on the plan.

Need financial help with Medicare’s costs? If you have low income and assets, you may qualify for a Medicare Savings Program that helps pay your Medicare premiums and out-of-pocket costs

Updated December 20, 2022

More on Medicare

• If I’m still working at 65, when do I sign up for Medicare?
• 9 things Medicare doesn’t cover
  
• Medicare eligibility: Do you qualify?