Medicare Part B is the medical insurance piece that covers doctor visits and outpatient care
Medicare Part B pays for services you receive outside a hospital — your doctor's office visits, lab tests, imaging like X-rays and ultrasounds, and outpatient surgery. It also covers some equipment and supplies your doctor orders, like wheelchairs or diabetic testing strips. 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 of your medical needs.
Part B requires a monthly premium that you pay, usually taken from your Social Security check. You also pay a yearly deductible before Part B starts to pay, and then you typically pay 20 percent of the cost for most services after that. The exact amounts change each year.
Key Takeaways
- Part B covers doctor visits, lab work, imaging, and outpatient procedures — anything your doctor orders that happens outside a hospital.
- You pay a monthly premium for Part B, a yearly deductible, and then 20 percent of the cost for most services after the deductible is met.
- If you delay enrolling in Part B when you first become may be able to access, you may pay a higher premium for the rest of your life.
- You can see any doctor who accepts Medicare; you do not need permission from an insurance company to visit a specialist.
What Part B actually pays for
Part B covers the services and supplies your doctor says you need for diagnosis or treatment. This includes office visits with your doctor, visits to urgent care centers, and emergency room visits (though the ER is technically covered by Part A if you are admitted to the hospital). Lab tests ordered by your doctor — blood work, urinalysis, and other diagnostics — are covered. Imaging services like X-rays, CT scans, and MRIs are covered when medically necessary.
Outpatient surgery and procedures are covered, meaning surgery that does not require an overnight hospital stay. Physical therapy, occupational therapy, and speech therapy are covered when your doctor orders them. Part B also covers some equipment and supplies: wheelchairs, walkers, oxygen equipment, diabetic supplies, and similar items that your doctor prescribes. Mental health services, including therapy and psychiatric visits, are covered under Part B.
Preventive services are covered at no cost to you — no deductible, no coinsurance. These include annual wellness visits, cancer screenings (mammograms, colonoscopies, Pap tests), cardiovascular screenings, and vaccinations like the flu shot and pneumonia vaccine. Part B does not cover routine dental care, eye exams for glasses or contacts, or hearing aids, though it does cover some eye care related to disease.
How much Part B costs
The standard monthly premium for Part B in 2024 is $164.90 for most people, but this amount increases each year. If your income is higher than a certain threshold, you pay a higher premium — this is called an Income-Related Monthly Adjustment Amount (IRMAA). The income thresholds and premium amounts change annually, so you should check your Medicare statements each year to see if your premium has changed.
After you pay your monthly premium, you also pay an annual deductible before Part B starts to pay. In 2024, the Part B deductible is $240. Once you have paid this deductible in a calendar year, Part B typically pays 80 percent of the approved amount for most services, and you pay the remaining 20 percent. This 20 percent payment is called coinsurance.
If you see a doctor who does not accept Medicare, you may have to pay the full cost yourself. Most doctors do accept Medicare, but it is worth confirming before your visit. Some doctors who accept Medicare also charge more than Medicare allows; in those cases, you pay the difference on top of your 20 percent coinsurance.
When to enroll in Part B and what happens if you miss the important date
You become may be able to access for Medicare at age 65. Your initial enrollment period is seven months long: it starts three months before the month you turn 65 and ends three months after. If you enroll during this window, your Part B coverage starts the month you turn 65 (or the month after, depending on when you sign up).
If you miss your initial enrollment period, you can still enroll during the General Enrollment Period, which runs from January 1 to March 31 each year. However, if you enroll late, your Part B coverage does not start until July of that year, and you may pay a higher premium for the rest of your life. The penalty is 10 percent of the standard premium for each full year you were may be able to access but did not enroll. This penalty is permanent, so it is important to enroll on time.
There is one exception: if you were covered by a group health plan through your job or your spouse's job when you turned 65, you may have a Special Enrollment Period that lets you enroll in Part B without penalty even after your initial enrollment period ends. You must enroll within eight months of losing that group coverage.
Part B and other Medicare coverage options
If you have Original Medicare (Part A and Part B), you can see any doctor or specialist without needing permission from an insurance company. You do not need a referral to see a specialist. However, Original Medicare does not have an out-of-pocket maximum, meaning your costs can grow very high if you have a serious illness or injury.
Many people add Medigap insurance (also called supplemental insurance) to help pay the costs that Part B does not cover — the deductible, coinsurance, and any charges above what Medicare allows. Medigap is sold by private insurance companies and has its own premiums and rules.
Alternatively, some people choose Medicare Advantage (Part C) instead of Original Medicare plus Medigap. Medicare Advantage is an all-in-one plan sold by private insurance companies that includes Part A, Part B, and usually Part D (prescription drugs). Medicare Advantage plans often have lower premiums but require you to use doctors in their network and may require referrals to see specialists.
How to find out what your doctor charges and what you will owe
Before a visit or procedure, you can call your doctor's office and ask what they charge and what Medicare approves for that service. You can also use the Medicare Physician Fee Schedule tool on the Centers for Medicare & Medicaid Services (CMS) website to look up what Medicare pays for specific services in your area.
After your visit, you will receive an Explanation of Benefits (EOB) from Medicare that shows what the provider charged, what Medicare approved, what Medicare paid, and what you owe. Keep these documents; they are your record of what you paid and can help you track whether you have met your deductible for the year.
Frequently Asked Questions
Do I have to enroll in Part B if I have Part A?
Part B is optional, but most people enroll because Part A alone does not cover doctor visits or outpatient care. If you delay enrolling, you may pay a higher premium later. If you are still working and covered by your employer's health plan, you may be able to delay without penalty.
Can I see any doctor with Part B?
Yes. Part B lets you see any doctor or specialist who accepts Medicare without needing a referral. However, if the doctor does not accept Medicare or charges more than Medicare allows, you may owe extra money beyond your 20 percent coinsurance.
What happens if I go over my deductible early in the year?
Once you have paid the $240 annual deductible, Part B pays 80 percent of approved charges for the rest of that calendar year, and you pay 20 percent. The deductible resets on January 1 each year.
Does Part B cover prescription drugs?
No. Prescription drug coverage is Part D, which is separate. You can enroll in a Part D plan when you first become may be able to access for Medicare, or during the annual enrollment period in the fall.
What if I cannot afford the Part B premium?
If your income is low, you may be able to get help paying your premiums through Medicaid or the Medicare Savings Programs. Contact your state Medicaid office or call 1-800-MEDICARE to learn what programs may be available in your state.