Medicare Part B covers medically necessary doctor services and outpatient care, such as:

• Visits with a doctor or other health care provider, including some doctor services when hospitalized.
• An annual wellness visit and preventive services, such as flu shots and mammograms.
• Clinical laboratory services, such as blood and urine tests.
• CT scans, electrocardiograms, MRIs, X-rays and some other diagnostic tests.
  
• Some health programs, such as cardiac rehab, obesity counseling and smoking cessation.
• Physical therapy, occupational therapy and speech-language pathology services.
• Diabetes care, including screenings, a prevention program, education and certain equipment.
• Outpatient mental health services.
• Durable medical equipment for use at home, like wheelchairs and walkers.
  
• Emergency department and outpatient surgery center services.
• A limited number of prescription drugs that you usually don’t administer yourself.

What Part B doesn’t cover:

• Most eye exams, eyeglasses and most contact lenses.
• Hearing aids and exams for fitting them.
• Dental exams, cleanings and X-rays as well as most dental care and procedures.
• Most prescription drugs.

In 2024, most people pay $174.70 a month for Part B. 

If you receive Social Security benefits, your premiums typically are deducted from your Social Security benefit payments. Some people may pay less than usual in years when the cost-of-living increase for their Social Security benefits is smaller than the annual increase in Part B premiums.

In 2024, if you’re single and earn more than $103,000 a year — based on what the IRS calls the modified adjusted gross income from your 2022 tax return — your monthly Part B premiums will be higher. That earnings limit is double for couples filing jointly, or $206,000. Each high earner pays $244.60 to $594.00 a month for Part B, depending on income.

You may be able to get this higher premium reduced or eliminated if your income has dropped since your tax return from two years ago because of certain life-changing events, such as the death of a spouse, a divorce or retirement.

You will pay a $240 deductible for Part B in 2024 before most coverage begins.

After that, you usually have to pay 20 percent of the Medicare-approved amount for covered services, called coinsurance. You may be able to receive some preventive services and screenings without having to pay the deductible or coinsurance.

Medicare decides how much providers should be paid for covered services. Almost all doctors accept the Medicare-approved payment amount, even if that is less than they usually charge. If your doctor charges more than the Medicare-approved amount for the services, you may have to pay up to 15 percent more in excess charges.

You may be able to buy supplemental insurance or qualify for financial assistance that covers many of these costs.
 

*This estimate assumes no Medigap policy was purchased. Your costs may be different.

You need to sign up for Part B at certain times or you may have to pay a penalty for the rest of your life. If you’re already receiving Social Security retirement benefits, you’ll be enrolled automatically in Medicare parts A and B at the beginning of the month you turn 65 or, if your birthday is on the first day of a month, during the previous month. (Puerto Rico’s rules differ.)

If you don’t have other insurance, you usually need to sign up for Part B when you're first eligible for Medicare, which is during the seven-month initial enrollment period that runs from three months before to three months after the month you turn 65.

If you or your spouse are still working and you have coverage through that employer’s plan, you may be able to delay signing up for Part B. But you must enroll within eight months of losing that employer-based coverage to avoid a penalty.

Be aware: If the company you're working for has fewer than 20 employees, you generally should sign up for Medicare parts A and B at age 65. Otherwise, you may have gaps in coverage.

If you miss those deadlines, you may have to pay a late enrollment penalty of 10 percent for each 12-month period you could've had Part B but didn’t sign up. The penalty is added to your monthly premium for as long as you have Part B.