Medicare Part B: Doctor Costs and Lab Tests

Medically Reviewed by Sarah Goodell on December 01, 2022
4 min read

Medicare Part B pays for outpatient medical care, such as doctor visits, some home health services, some laboratory tests, some medications, and some medical equipment. (Hospital and skilled nursing facility stays are covered under Medicare Part A, as are some home health services.)

If you qualify to get Medicare Part A, you're also qualified for Medicare Part B. If you're age 65 and are already receiving Social Security checks, you're automatically enrolled. However, you may opt out.

If you are age 65 or older but are not yet getting Social Security payments, you can still apply. Call Social Security at 800-772-1213, visit the web site at, or apply at your local Social Security office.

For Part B, you have to pay a monthly fee (called a premium), which is usually taken out of your Social Security payment. For 2023, this fee is $164.90 per month.

But if you have a higher than average personal income (over $97,000) or household income (over $194,000), you will have to pay a higher monthly premium for Medicare Part B. The monthly adjustment will vary from about $65.90 to $395.60, with a maximum premium of $560.50 in 2023 (for individuals earning $500,000 or more per year or couples earning $750,000 or more).

There’s also a yearly deductible of $226 in 2023. After you pay $226 yourself, your benefits kick in. After that, Medicare will pay 80% of the cost of most Part B services, and you (or your Medigap policy) pay the other 20%.

Finally, it’s important to know that there's a penalty for signing up late for Part B. If you don't sign up for Medicare Part B when you first become eligible (and you don’t have comparable coverage from an employer), your monthly fee may be higher than $164.90. You’ll pay a lifetime 10% penalty for every 12 months you delay your enrollment.

  • Medical and other services. Medicare Part B pays 80% of most doctor's services, outpatient treatments, and durable medical equipment (like oxygen or wheelchairs). You pay the other 20%. Medicare also pays for mental health care costs.
  • Laboratory and radiology services. This includes blood tests, X-rays, and other tests.
  • Outpatient hospital services. Medicare Part B covers some of these fees. You must pay a co-payment for outpatient hospital services The exact amount varies depending on the service.
  • Home health care. Medicare Part B pays for nurses and some therapists to provide occasional or part-time services in your home. As long as the provider is certified by Medicare, you pay nothing -- except for 20% of the charges for some medical equipment, such as wheelchairs and walkers.
  • Preventive services. Medicare Part B helps pay for a number of tests, screenings, vaccinations, and a one-time “Welcome to Medicare” physical exam and annual wellness exams. Many of these services are available at no cost at the time of the visit. Part B also covers screening and counseling for alcohol use (for people who are not considered alcoholic), obesity screening and counseling, screening for depression, sexually transmitted infections screening and counseling, and cardiovascular behavioral counseling.
  • Blood for transfusions. After the first three pints within a calendar year, Medicare pays 80% of the costs for blood you need as an outpatient.

Medicare Parts A and B are sometimes called "Original Medicare." Original Medicare allows you the freedom to see any doctor who accepts Medicare. Most do. It’s not like an HMO, where you can see only doctors in the plan’s network.

Many people get signed up for Medicare Part B automatically. If you do not want it, you must opt out. Otherwise, the money is automatically taken out of your Social Security payments. You should get instructions on how to do this when you are first mailed your Medicare packet.

Some people opt out of Medicare Part B because they still have coverage through union or employer health insurance. As long as your coverage is considered “creditable” you will not pay a penalty for signing up late. Talk to the group benefits administrator of your plan before opting out of Part B. If your coverage does not meet this criteria, or you have no other coverage, you may pay a lifetime penalty if you sign up later for Part B.

If you have traditional Medicare, make sure your doctor "accepts assignment" before you make an appointment. Medicare decides what it will pay for any particular medical service. This is called the Medicare-approved amount. If your doctor is willing to accept what Medicare pays and won't charge you any more, they are said to "accept assignment." But if your health care provider does not accept assignment and charges more than Medicare pays, you will have to pay the difference.

For more information about Medicare Part B, see the Medicare web site at or call 800-MEDICARE (633-4227).