Part B is the doctor and outpatient insurance piece of Medicare

Part B covers visits to doctors, specialists, and outpatient care — the medical services you receive when you are not admitted to a hospital overnight. It pays for office visits, lab tests, imaging like X-rays and ultrasounds, mental health counseling, physical therapy, and certain medical equipment you use at home. Part B is optional, but most people who have Part A (hospital insurance) also enroll in Part B because the two work together to cover most routine medical needs.

Part B is not free. You pay a monthly premium that comes out of your Social Security check or is billed directly to you. The standard premium in 2024 is $164.90 per month for most people, though it is higher if your income is above a certain threshold. You also pay a yearly deductible before Part B starts to pay, and then you typically pay 20 percent of the cost of covered services after that.

Part B is run by Medicare, which is part of Social Security Administration. You enroll during your initial enrollment period when you first become may be able to access at 65, or during the general enrollment period each January through March if you missed the important date. If you delay enrolling without a valid reason, you may face a permanent penalty on your premium.

Key Takeaways

  • Part B covers doctor visits, lab work, imaging, mental health care, and outpatient procedures — anything you receive without being admitted to the hospital overnight.
  • You pay a monthly premium (currently around $165 for most people), a yearly deductible, and then 20 percent of the cost of most covered services.
  • Part B does not cover routine dental, vision, or hearing care, and it does not cover prescription drugs — you need Part D or a separate plan for medications.
  • You must enroll during your initial enrollment period at age 65 or face a permanent increase to your premium if you sign up later.
  • If you are still working and covered by an employer health plan, you may be able to delay Part B enrollment without penalty.

What Part B actually pays for

Part B covers the cost of seeing your primary care doctor and any specialist you are referred to. This includes office visits, consultations, and follow-up appointments. It also covers preventive care visits at no cost to you — annual wellness exams, screenings for cancer and heart disease, and vaccinations like the flu shot and pneumonia vaccine are all covered with no deductible or copay.

Diagnostic tests and imaging are covered: blood work, urinalysis, EKGs, chest X-rays, ultrasounds, and CT scans ordered by your doctor. Part B also covers outpatient procedures performed in a hospital outpatient department or an ambulatory surgery center — for example, a cataract removal or a colonoscopy. Mental health services including therapy and psychiatric visits are covered, as is physical therapy and occupational therapy when medically necessary.

Durable medical equipment — wheelchairs, walkers, oxygen equipment, diabetic supplies, and similar items — is covered if your doctor prescribes it. Home health care, including nursing visits and therapy at home when you are homebound, is covered. Ambulance transport to a hospital is covered if medically necessary. Chemotherapy and radiation for cancer are covered whether given in an office or outpatient facility.

What Part B does not cover

Part B does not cover routine dental work, eye exams for glasses or contacts, or hearing aids. If you need these services, you must purchase a separate dental, vision, or hearing plan, or pay out of pocket. Prescription medications are not covered by Part B — you need Part D prescription drug coverage or a Medicare Advantage plan that includes drug coverage to help pay for pills and injectables you take at home.

Cosmetic procedures are not covered unless they are medically necessary — for example, reconstructive surgery after an accident or mastectomy is covered, but a facelift is not. Long-term care in a nursing home or assisted living facility is not covered by Part B. Routine foot care, including nail trimming, is not covered unless you have diabetes or a related condition. Weight loss programs and most weight loss medications are not covered.

Services from providers who are not enrolled in Medicare are not covered, or are covered at a much lower rate. If you see an out-of-network provider, you may owe more. Some experimental treatments are not covered unless they are part of an approved clinical trial.

How much you pay with Part B

Your out-of-pocket costs with Part B have three parts: the monthly premium, the yearly deductible, and coinsurance on covered services. The monthly premium is deducted from your Social Security benefit or billed to you directly. For 2024, the standard premium is $164.90 per month, but it increases each year. If your income is above $97,000 as a single person or $194,000 as a married couple filing jointly, you pay a higher premium — the exact amount depends on your income from two years ago.

The yearly deductible for Part B in 2024 is $240. Once you have paid this amount out of pocket for covered services, Part B begins to pay its share. After you meet the deductible, you typically pay 20 percent of the Medicare-approved amount for most services, and Medicare pays 80 percent. For some services like office visits or lab work, you may pay a fixed copay instead of a percentage.

If you see a provider who does not accept Medicare assignment — meaning they do not agree to accept Medicare's approved amount as full payment — you may owe more than 20 percent. This is called balance billing. You can check whether a doctor accepts assignment before you schedule an appointment by calling their office or using the Medicare provider search tool on Medicare.gov.

Part B and other Medicare coverage options

You can have Part B as traditional Medicare (also called Original Medicare), which means you use any doctor or hospital that accepts Medicare. Alternatively, you can choose a Medicare Advantage plan (Part C), which is an all-in-one plan run by a private insurance company that includes Part B coverage plus usually Part D drug coverage and sometimes dental or vision. With Medicare Advantage, you typically pay a lower or zero monthly premium, but you have a network of doctors and may need referrals to see specialists.

If you have Original Medicare Part B, you can also purchase a Medigap policy (supplemental insurance) to help pay the costs that Medicare does not cover — the deductible, coinsurance, and copays. Medigap plans are sold by private insurance companies and have their own monthly premiums, but they can significantly reduce your out-of-pocket costs. You have a limited window to buy Medigap without medical underwriting: the six months after you turn 65 and enroll in Part B.

You must have Part B (or Part C, which includes Part B coverage) to purchase a Medigap plan. You cannot combine Medigap with Medicare Advantage — you choose one or the other.

When to enroll in Part B and what happens if you miss the important date

Your initial enrollment period is the three months before the month you turn 65, the month you turn 65, and the three months after. If you enroll during this window, your Part B coverage begins the month you turn 65 (or the first day of the month you turn 65 if you enroll in the month you turn 65). This is the only time you can enroll without penalty.

If you miss your initial enrollment period and do not have a valid reason, you can still enroll during the general enrollment period from January 1 through March 31 each year. However, your coverage will not begin until July 1 of that year, and you will pay a permanent 10 percent increase to your Part B premium for each full year you delayed enrollment. This penalty stays with you for life, so it is important to enroll on time.

You do not have to enroll in Part B right at 65 if you are still working and covered by an employer health plan. If your employer has 20 or more employees, you can delay Part B without penalty as long as you are actively employed and covered by that plan. Once you leave that job or lose the coverage, you have eight months to enroll in Part B without penalty. You will need to show proof of your employer coverage when you enroll.

Questions to ask your doctor or Medicare

Before you have a procedure or see a new specialist, ask your doctor whether the service is covered by Medicare Part B and whether they accept Medicare assignment. Ask what your out-of-pocket cost will be — your copay, coinsurance, or deductible responsibility. If the cost seems high, ask whether there are alternative treatments that might be less expensive.

If you are unsure whether you need Part B, whether you should enroll now or delay, or whether a Medigap plan makes sense for you, call Medicare at 1-800-MEDICARE (1-800-633-4227). They can answer questions about your specific situation. You can also speak with a counselor at your State Health Insurance information Program (SHIP), which is a free service that helps older adults understand Medicare options.

Frequently Asked Questions

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

Part B is optional, but if you do not enroll when you are first may be able to access and you do not have a valid reason to delay (like active employer coverage), you will pay a permanent 10 percent premium increase for each year you waited. Most people should enroll at 65 to avoid this penalty.

What if my doctor is not in the Medicare network?

With Original Medicare Part B, there is no network — any doctor who accepts Medicare can treat you. However, if a doctor does not accept Medicare assignment, they can charge you more than Medicare's approved amount. Always ask before your visit whether the doctor accepts assignment.

Does Part B cover prescription drugs?

No. Part B does not cover medications you take at home. You need Part D prescription drug coverage, which you can add to Original Medicare, or you can choose a Medicare Advantage plan that includes drug coverage. You enroll in Part D during the same initial enrollment period as Part B.

Can I switch from Part B to Medicare Advantage later?

Yes. You can switch during the annual enrollment period from October 15 through December 7 each year, and your new coverage begins January 1. You can also switch back to Original Medicare during this window. Outside this period, you can only switch if you have a may have access to life event like moving out of your plan's service area.

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

Original Medicare Part B coverage works the same in every state, so you can see any Medicare-accepting doctor anywhere in the country. If you have a Medicare Advantage plan, you may need to switch plans when you move because plans are regional. Contact your plan or Medicare to find out what coverage is available in your new state.