Medicare Part B Explained
Medical Insurance Made Simple
Medicare Part B is often called medical insurance. It helps cover many of the healthcare services people use outside of an inpatient hospital stay, including doctor visits, outpatient care, preventive services, diagnostic tests, durable medical equipment, and certain other medically necessary services.
If Medicare Part A is mainly about hospital insurance, Medicare Part B is mainly about medical care you receive from doctors, outpatient providers, clinics, and other healthcare professionals.
Our goal is to help you understand what Medicare Part B does, what it may help cover, what it does not cover, and what costs you may be responsible for.
What Is Medicare Part B?
Medicare Part B is the part of Medicare that helps cover medically necessary doctor services, outpatient care, preventive care, durable medical equipment, and certain other medical services.
Part B is one of the two parts of Original Medicare, along with Medicare Part A. Original Medicare includes Part A and Part B, and after you sign up for both, you can choose how you want to receive your Medicare coverage.
A simple way to remember it:
Part B helps cover doctor care, outpatient medical services, preventive care, and certain medical equipment.
Part B does not cover everything, and in most cases you will still have out-of-pocket costs.
What Does Medicare Part B Cover?
Medicare Part B covers a wide range of medical services when Medicare’s rules are met.
Doctor and Other Healthcare Provider Services
Part B helps cover medically necessary services from doctors and other healthcare providers. Part B covers medically necessary doctor services and most preventive services.
This may include services from:
Doctors
Nurse practitioners
Physician assistants
Clinical psychologists
Clinical social workers
Physical therapists
Occupational therapists
Speech-language pathologists
Other Medicare-covered providers
These services may be provided in a doctor’s office, outpatient clinic, hospital outpatient department, or sometimes while you are in the hospital receiving care from a doctor.
Outpatient Care
Part B generally helps cover many services you receive without being formally admitted as a hospital inpatient.
This can include outpatient doctor visits, outpatient hospital services, certain outpatient procedures, diagnostic testing, and other medically necessary services. Outpatient hospital care often involves paying 20% of the Medicare-approved amount for doctor and provider services after the Part B deductible, plus possible hospital copayments for outpatient hospital services.
One important point: being physically inside a hospital does not always mean you are an inpatient. Your hospital status matters because it can affect whether services are covered under Part A or Part B.
Preventive Services
Part B covers many preventive and screening services. Preventive services can include exams, vaccines, lab tests, screenings, health monitoring programs, counseling, and education to help you take care of your health.
Preventive services may include things such as:
Certain cancer screenings
Diabetes screenings
Cardiovascular disease screenings
Depression screenings
Flu, COVID-19, pneumococcal, and hepatitis B vaccines
“Welcome to Medicare” preventive visit
Yearly wellness visit
Many preventive services cost nothing if you get them from a healthcare provider who accepts assignment.
Durable Medical Equipment
Medicare Part B may cover durable medical equipment, often called DME, when it is medically necessary and ordered by your doctor or other healthcare provider for use in your home. DME is defined as equipment that is durable, used for a medical reason, generally only useful to someone who is sick or injured, used in the home, and expected to last at least three years.
Examples may include:
Walkers
Wheelchairs
Hospital beds
Oxygen equipment
Certain blood sugar monitors and supplies
CPAP equipment
Crutches
Canes
After you meet the Part B deductible, you generally pay 20% of the Medicare-approved amount for covered DME if the supplier accepts assignment.
Diagnostic Tests
Part B may help cover diagnostic tests ordered by your provider to help find, diagnose, or treat a medical problem. Examples of diagnostic non-laboratory tests are CT scans, MRIs, EKGs, X-rays, and PET scans.
In many cases, after you meet your Part B deductible, you pay 20% of the Medicare-approved amount for covered diagnostic tests. If a test is performed in a hospital outpatient setting, additional facility costs may apply.
Outpatient Mental Health Care
Medicare Part B also covers a wide range of outpatient mental health services. These can include services for diagnosing and treating mental health conditions such as depression and anxiety, and may include individual therapy, group therapy, psychiatric evaluation, medication management, and certain other covered services.
After you meet the Part B deductible, you generally pay 20% of the Medicare-approved amount for visits to diagnose or treat a mental health condition, and you may pay an additional amount if the services are provided in a hospital outpatient setting.
Ambulance Services
Part B may cover ground ambulance transportation when traveling in another vehicle could endanger your health and you need medically necessary transportation to an appropriate medical facility. Medicare may also cover emergency air ambulance transportation in certain situations when rapid transport is needed and ground transportation cannot provide it.
After you meet the Part B deductible, you generally pay 20% of the Medicare-approved amount for covered ambulance services.
Limited Outpatient Prescription Drugs
Most prescription drug coverage is handled through Medicare Part D, but Part B can cover a limited number of outpatient prescription drugs under certain conditions. Part B usually covers drugs you would not typically give yourself, such as certain injectable or infused drugs given by a licensed medical provider.
Part B-covered drug situations can include some drugs used with durable medical equipment, certain injectable or infused drugs, some vaccines, certain ESRD-related drugs, and other limited categories. Medicare drug coverage through Part D covers many drugs that Part B does not cover.
What Does Medicare Part B Not Cover?
Medicare Part B does not cover every healthcare service.
For example, Original Medicare generally does not cover routine dental services such as cleanings, fillings, tooth extractions, dentures, or implants in most cases.
Medicare also does not cover routine eye exams for eyeglasses or contact lenses, and it does not cover hearing aids or exams for fitting hearing aids.
Part B also does not usually cover most self-administered prescription drugs. Those are generally handled through Medicare Part D or other drug coverage. Part D covers many drugs that Part B does not cover.
A simple way to think about it:
Part B covers a lot of medical care, but it does not cover everything you may need.
That is why many people take time to understand prescription drug coverage, Medicare Supplement Insurance, Medicare Advantage, and other coverage options.
Medicare Part B Costs
Medicare Part B is not free for most people.
In 2026, the standard Medicare Part B premium is $202.90 per month, although some people pay more depending on income. You pay the Part B premium each month even if you do not receive any Part B-covered services.
In 2026, the Part B deductible is $283. You pay this deductible once per year before Original Medicare starts to pay for many Part B services.
After the deductible is met, you usually pay 20% of the Medicare-approved amount for many covered Part B services or items, as long as your provider accepts the Medicare-approved amount as full payment, also called accepting assignment.
What Is Assignment?
Assignment means that a doctor, provider, or supplier agrees to accept the Medicare-approved amount as full payment for a covered service or item.
This matters because if your provider accepts assignment, your share of the cost may be lower. What you owe can depend on whether your doctor accepts assignment, how much your doctor charges, the type of facility, where you receive the service, and whether you have other insurance.
Before receiving care, it is often smart to ask:
Does this provider accept Medicare?
Do they accept assignment?
Is this service covered by Medicare?
What might I owe out of pocket?
Part B Late Enrollment Penalty
Timing matters with Medicare Part B.
If you do not sign up for Part B when you are first eligible, you may have to pay a late enrollment penalty. The penalty may apply for as long as you have Part B, and the longer you wait to sign up, the higher the penalty may be.
Some people can delay Part B without a penalty if they have qualifying coverage through current employment. But the rules can be confusing, especially if you have retiree coverage, COBRA, marketplace coverage, or employer coverage from a smaller employer.
If you are approaching 65 and still working, this is one area where it is especially important to ask questions before making decisions.
Part A vs. Part B
Medicare Part A and Part B work together, but they cover different types of care.
Part A is hospital insurance. It generally helps cover inpatient hospital care, skilled nursing facility care, hospice care, and some home health care.
Part B is medical insurance. It generally helps cover doctor visits, outpatient care, preventive services, durable medical equipment, diagnostic testing, and other medically necessary services.
Together, Part A and Part B make up Original Medicare. After you sign up for Part A and Part B, you can choose either Original Medicare, a Medicare Advantage as the way you receive your Medicare health coverage or purchase a Medigap (Medicare Supplement) plan.
Part B and Original Medicare
If you choose Original Medicare, Part B becomes one of the key pieces of your coverage.
With Original Medicare, you can generally go to any doctor or hospital that takes Medicare anywhere in the United States. You may also choose to add a separate Part D prescription drug plan and may choose to buy Medicare Supplement Insurance, also called Medigap, to help lower your share of certain costs.
This is one reason Part B is so important: it is the foundation for many of the medical services you are likely to use throughout the year.
Part B and Medicare Advantage
If you choose Medicare Advantage, also called Part C, you still must have both Part A and Part B to join a Medicare Advantage plan. Medicare Advantage is an alternative way to receive your Medicare benefits through Medicare-approved private companies.
Even if you join a Medicare Advantage plan, you generally must continue paying your Part B premium. You must have Part B and keep paying your Part B premium to stay in a Medicare Advantage plan.
Why Medicare Part B Matters
Medicare Part B is one of the most important parts of Medicare because it helps cover many everyday medical services.
If you see doctors, receive outpatient care, use preventive services, need diagnostic tests, receive outpatient mental health care, use certain medical equipment, or need covered ambulance transportation, Part B may play a role.
Understanding Part B helps you better understand:
Your medical coverage
Your monthly costs
Your annual deductible
Your share of covered services
How Original Medicare works
How Medicare Advantage works
Why enrollment timing matters
Part B is not the entire Medicare picture, but it is one of the most important pieces.
Common Questions About Medicare Part B
Is Medicare Part B required?
Part B is not always automatic for everyone, and whether you should enroll right away depends on your situation. Many people enroll in both Part A and Part B when first eligible, but some people delay Part B because they have qualifying employer coverage through current work. If you are unsure, it is important to understand the rules before delaying enrollment.
What does Medicare Part B mainly cover?
Part B mainly helps cover doctor services, outpatient care, preventive services, durable medical equipment, diagnostic tests, outpatient mental health care, ambulance services, and certain other medically necessary services. Part B covers medically necessary doctor services and most preventive services.
Does Medicare Part B cover prescriptions?
Part B covers a limited number of outpatient prescription drugs under certain conditions. Most outpatient prescription drug coverage is handled through Medicare Part D or drug coverage included in some Medicare Advantage plans.
Does Medicare Part B cover preventive care?
Yes, Part B covers many preventive and screening services. Many preventive services cost nothing if your provider accepts assignment.
How much does Part B cost?
In 2026, the standard Part B premium is $202.90 per month, and the Part B deductible is $283. After you meet the deductible, you usually pay 20% of the Medicare-approved amount for many covered Part B services.
Can I have Part A without Part B?
Some people have Part A before they enroll in Part B, especially if they are still working and have employer coverage. But Part B is required for certain Medicare choices, including Medicare Advantage and Medigap (also known as Medicare Supplement plans). You must have Part B and keep paying your Part B premium to keep a Medigap policy, and you must have Part B and keep paying your Part B premium to stay in a Medicare Advantage plan.
The Simple Takeaway
Medicare Part B is medical insurance.
It helps cover many doctor services, outpatient services, preventive services, diagnostic tests, durable medical equipment, and other medically necessary care.
But Part B is not free, it does not cover everything, and late enrollment can create penalties that may last as long as you have Part B.
Understanding Part B is one of the most important steps in understanding Medicare as a whole.
Need Help Understanding How Part B Fits With the Rest of Medicare?
Medicare Part B is only one piece of your coverage.
If you are trying to understand how Part B works with Part A, prescription drug coverage, Medicare Supplement Insurance, or Medicare Advantage, we can help connect you with a licensed Medicare professional who can answer questions based on your situation.