Part B is Medicare's medical insurance for doctor visits and outpatient care

Part B is the part of Medicare that pays for services from doctors, specialists, and hospital outpatient departments. It covers office visits, diagnostic tests, preventive care, mental health treatment, and certain medical equipment. Most people pay a monthly premium for Part B, and it works alongside Part A (hospital insurance) to cover the bulk of what happens outside the hospital.

Part B is optional, but if you delay signing up when you first turn 65, you will pay a higher premium for as long as you have Medicare. The standard way to get Part B is through Original Medicare, though you can also choose a Medicare Advantage plan (Part C) that includes Part B coverage bundled in.

Key Takeaways

  • Part B covers doctor office visits, specialist consultations, lab work, imaging, and preventive screenings at no cost to you once you meet your deductible.
  • You pay a monthly premium for Part B, a yearly deductible, and then 20 percent coinsurance for most services after the deductible is met.
  • Part B does not cover routine dental, vision, or hearing care, though some preventive eye exams and hearing tests may be covered in limited cases.
  • If you do not sign up for Part B when you first turn 65, you will owe a permanent penalty on your monthly premium unless you have other health insurance.

What Part B actually covers

Part B pays for visits to your primary care doctor, any specialist you are referred to, and urgent care clinics. It covers the full cost of preventive services with no deductible or coinsurance — things like annual wellness visits, cancer screenings, blood pressure checks, and vaccines. Once you have paid your yearly deductible (which changes each year), Part B covers 80 percent of the cost of other services, and you pay the remaining 20 percent.

Diagnostic services fall under Part B: blood tests, X-rays, CT scans, ultrasounds, and EKGs all count. Mental health treatment is covered the same way as physical health — therapy visits and psychiatric appointments are subject to the same deductible and coinsurance. Part B also covers certain medical equipment and supplies your doctor orders, such as wheelchairs, walkers, oxygen equipment, and diabetic testing supplies.

Ambulance transport to a hospital is covered by Part B if medically necessary. Physical therapy, occupational therapy, and speech therapy are covered when ordered by a doctor for a medical condition. Home health services — nursing care, therapy, or medical equipment delivered to your home — are covered under Part A if you meet the requirements, but some home health services fall under Part B depending on the type of care.

What Part B does not cover

Routine dental work, dentures, and dental implants are not covered by any part of Medicare. Routine eye exams and glasses or contact lenses are not covered, though Medicare does cover one pair of glasses or contact lenses after cataract surgery. Routine hearing exams and hearing aids are not covered by Part B, though some preventive hearing tests may be included in your annual wellness visit.

Cosmetic surgery is not covered unless it is medically necessary to repair an injury or birth defect. Weight loss surgery is not covered. Acupuncture is not covered in most cases. Experimental treatments and clinical trials may not be covered unless you are enrolled in a Medicare-approved trial. Prescription drugs are not covered by Part B — that is Part D's role — though some drugs given in a doctor's office or hospital outpatient setting are covered.

How much Part B costs

The standard Part B monthly premium is deducted from your Social Security check if you receive benefits, or you pay it directly to Medicare if you do not. The premium amount changes each year. Most people pay the standard amount, but if your income is above a certain threshold, you will pay a higher premium called an Income-Related Monthly Adjustment Amount (IRMAA). This is based on your tax return from two years prior.

After you pay your yearly deductible, you pay 20 percent coinsurance for most Part B services. Some preventive services have no cost at all. If you see an out-of-network provider who does not accept Medicare assignment, you may pay more than 20 percent — up to 15 percent above the Medicare-approved amount in most cases. This is why checking whether your doctor accepts Medicare assignment matters before your visit.

If you cannot afford Part B premiums and coinsurance, you may be able to get help through a program called Medicaid (if your state offers it and you meet income limits) or through a Medicare Savings Program, which is run by your state and helps pay Part B premiums and cost-sharing for people with limited income.

Original Medicare versus Medicare Advantage for Part B

If you choose Original Medicare, you get Part B coverage directly from the federal government. You can see any doctor or specialist who accepts Medicare, and you pay the standard deductible and coinsurance. You will also want to buy a Medigap policy (supplemental insurance) to cover the 20 percent coinsurance and deductible, because those costs can add up.

Medicare Advantage (Part C) is an alternative way to get Part B coverage. Private insurance companies offer these plans, and they bundle Part A, Part B, and usually Part D (prescription drugs) into one plan. Medicare Advantage plans often have lower or no monthly premiums, but they typically have networks — you must see doctors in the plan's network, or you pay more. Some Medicare Advantage plans cover dental, vision, or hearing care that Original Medicare does not, which can be valuable if those services matter to you.

The choice between Original Medicare and Medicare Advantage depends on your health, your doctors, and your budget. If you have a preferred doctor who does not accept Medicare Advantage plans in your area, Original Medicare with a Medigap policy may be better. If you want dental or vision coverage and can accept a network, Medicare Advantage might save you money overall.

When to sign up for Part B and what happens if you miss the important date

You become may be able to access for Medicare at 65. Your Initial Enrollment Period is the seven-month window that starts three months before the month you turn 65 and ends three months after. If you sign up during this window, your Part B coverage starts the month you turn 65 (or the month after, depending on when in the month you sign up).

If you miss your Initial Enrollment Period and do not have other health insurance, you will owe a permanent penalty on your Part B premium. The penalty is 10 percent of the standard premium for each full year you were may be able to access but did not sign up. This penalty stays with you for life, even if you sign up later. The only exceptions are if you were still working and covered by your employer's health plan, or if you were covered by your spouse's employer plan.

If you miss the important date but had other health insurance, you have an eight-month window after that coverage ends to sign up for Part B without penalty. This is called a Special Enrollment Period. You will need to prove you had the other coverage — usually a letter from your employer or former employer stating the dates of coverage.

Questions to ask your doctor and Medicare

Before your first visit as a Medicare patient, ask your doctor's office whether they accept Medicare assignment. This means they agree to accept Medicare's approved amount as full payment (except for your deductible and coinsurance). If they do not, you could owe more.

Ask your doctor which services are preventive and covered at no cost, and which are not. Ask whether any tests or procedures they are ordering are covered by Part B, or whether you should check with Medicare first. If you are considering a procedure, ask whether it is covered and what your out-of-pocket cost will be.

Contact Medicare directly at 1-800-MEDICARE (1-800-633-4227) if you have questions about coverage, costs, or whether you need to sign up. You can also visit Medicare.gov to review your coverage and find providers in your area.

Frequently Asked Questions

Do I have to take Part B when I turn 65?

Part B is optional, but if you delay signing up without other health insurance, you will pay a permanent 10 percent penalty on your monthly premium. If you are still working and covered by your employer's health plan, you can delay without penalty, but you must sign up within eight months of losing that coverage.

What is the difference between Part B and a Medigap policy?

Part B is Medicare's medical insurance that covers doctor visits and outpatient care. A Medigap policy is supplemental insurance sold by private companies that pays for the deductible and coinsurance that Part B does not cover. You buy Medigap separately if you choose Original Medicare.

Can I use my Part B coverage at any hospital?

Yes, with Original Medicare you can go to any hospital that accepts Medicare. With Medicare Advantage, you must use hospitals in your plan's network, or you will pay more. Check your plan documents to see which hospitals are in-network.

Does Part B cover prescription drugs?

No. Prescription drugs are covered by Part D, which is a separate prescription drug plan you buy from a private insurance company. Some drugs given in a doctor's office or hospital outpatient setting are covered by Part B, but pills you take at home are not.

What happens to my Part B coverage if I move to another state?

Your Part B coverage continues no matter where you move. If you have a Medicare Advantage plan, you may need to switch plans because networks vary by state. Contact your plan or Medicare to understand your coverage in your new location.