Medicare Part B Basics

Medicare Part B is the part of Original Medicare that provides medical coverage. Part B covers certain doctors’ services, outpatient care, medical supplies, and preventive services.[1][2]

Everyone who qualifies for Medicare qualifies for Part B.

TIP: Medicare Part A is the other part of Original Medicare along with Medicare Part B. Part A is hospital insurance and part B is medical insurance. Together Parts A and B provide all the essential coverage a person will need from routine check-ups to hospital visits.

What Does Medicare Part B Cover?

Medicare Part B (Medical Insurance) helps cover medically-necessary services like doctors’ services, outpatient care, medical supplies, and preventive services.

Medically-necessary services include but are not limited to:

  • Abdominal Aortic Aneurysm Screening
  • Ambulance Services
  • Blood
  • Bone Mass Measurement (Bone Density)
  • Cardiac Rehabilitation
  • Cardiovascular Screenings
  • Chiropractic Services (limited)
  • Clinical Laboratory Services
  • Clinical Research Studies
  • Colorectal Cancer Screenings
  • Defibrillator (Implantable Automatic)
  • Diabetes Screenings
  • Diabetes Self-Management Training
  • Diabetes Supplies
  • Doctor Services
  • Durable Medical Equipment (like walkers)
  • EKG Screening
  • Emergency Department Services
  • Eyeglasses (limited)
  • Federally-Qualified Health Center Services
  • Flu shots
  • Foot Exams and Treatment (Diabetes-related)
  • Glaucoma Tests
  • Hearing and Balance Exams
  • Hepatitis B Shots
  • HIV Screening
  • Home Health Services
  • Kidney Dialysis Services and Supplies
  • Kidney Disease Education Services
  • Mammograms (screening)
  • Medical Nutrition Therapy Services
  • Mental Health Care (outpatient)
  • Non-doctor Services
  • Occupational Therapy
  • Outpatient Medical and Surgical Services and Supplies
  • Pap Tests and Pelvic Exams (includes clinical breast exam)
  • Physical Exams
  • Physical Therapy
  • Pneumococcal Shot
  • Prescription Drugs (limited)
  • Prostate Cancer Screenings
  • Prosthetic/Orthotic Items
  • Pulmonary Rehabilitation
  • Rural Health Clinic Services
  • Second Surgical Opinions
  • Smoking Cessation (counseling to stop smoking)
  • Speech-Language Pathology Services
  • Surgical Dressing Services
  • Telehealth
  • Tests (other than lab tests)
  • Transplants and Immunosuppressive Drugs

Some of these services are covered for free in the right setting, for example, physical exams at your annual checkup. Other services are subject to the Part B deductible and coinsurance.

FACT: The Affordable Care Act of 2010 included free preventative services for Medicare. These include a free annual wellness visit, and some free tests and screenings. Make sure to consult with a doctor before assuming a service is free, since some services depend on age and other factors. See a list of preventative and screening services covered under Part B.

Medicare Part B Costs Overview

Part B costs include a monthly premium and some out-of-pocket costs like a deductible, and copays or coinsurance depending on the service.

Medicare Part B is subject to a late enrollment penalty for those who don’t sign up when they first become eligible, although in some cases it can be deferred without cost (such as when a person has other creditable coverage through an employer).

Part B Late Enrollment Penalty: Your monthly premium for Part B may go up 10% of the standard premium for each full 12-month period that you could have had Part B, but didn’t sign up for it. Also, you may have to wait until the General Enrollment Period (from January 1 to March 31) to enroll in Part B. Coverage will start July 1 of that year.

Part B Cost Assistance: Part B costs can be lowered based on income via state-based Medicare Savings Programs.

Medicare Part B Premium

What you pay for your Medicare Part B premium changes slightly each year and is based on income and when you enroll. For 2021, the standard Part B premium is $148.50.

To give you an idea of how this changes year-to-year, the Part B premium was $144.60 in 2020.

Part B Deductible and Coinsurance

Another cost of Part B is the Part B deductible and the related 20% coinsurance.

For 2021, the Part B deductible is $203. In 2020 it was $198. After you meet your deductible for the year, you typically pay 20% of the Medicare-approved amount for most doctor services (including most doctor services while you’re a hospital inpatient), outpatient therapy, and durable medical equipment (DME).


While most people pay the standard amount for their Medicare Premiums, you may pay less with assistance programs or more based on Modified Adjusted Gross Income (MAGI). If your income is high enough, you’ll pay the standard premium amount plus an additional amount called the Income Related Monthly Adjustment Amount (IRMAA).

The IRMAA Part B costs chart below from Medicare.Gov shows the standard premium and IRMAA adjusted premiums for 2021 based on income.

If your yearly income in 2019 (for what you pay in 2021) was You pay each month (in 2021)
File individual tax return File joint tax return File married & separate tax return
$88,000 or less $176,000 or less $88,000 or less $148.50
above $88,000 up to $111,000 above $176,000 up to $222,000 Not applicable $207.90
above $111,000 up to $138,000 above $222,000 up to $276,000 Not applicable $297.00
above $138,000 up to $165,000 above $276,000 up to $330,000 Not applicable $386.10
above $165,000 and less than $500,000 above $330,000 and less than $750,000 above $88,000 and less than $412,000 $475.20
$500,000 or above $750,000 and above $412,000 and above $504.90

  1. Part B costs. Medicare.Gov.
  2. What does Part B of Medicare (Medical Insurance) cover? HHS.Gov.