What is Medicare Part B?

Fact Checked
Expert reviewed by: Ron Elledge, Medicare consultant
Published: 3/26/2021


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Ron Elledge
Medicare Consultant and Author
Ron Elledge
Medicare Consultant and Author

Ron Elledge is a seasoned Medicare consultant and author of “Medicare Made Easy.” As a Medicare expert, he regularly consults beneficiaries on Medicare rules, regulations, and strategies.

Medicare Part B, sometimes referred to as the “medical” part of Medicare, covers doctor and other provider visits and services, along with preventive care. It’s part of Original Medicare, which is made up of parts A and B.

Who is Eligible for Medicare Part B?

Your eligibility to enroll in Part B depends on when you are eligible for Medicare. If you meet the qualifications to enroll in Medicare when you turn 65, you have a seven-month Initial Enrollment Period (IEP) to enroll in Part B. This period includes the three months before you turn 65, the month you turn 65, and the three months after you turn 65.

If you miss your IEP, you can enroll during the General Enrollment Period or a Special Enrollment period. However, you may be liable for a late enrollment penalty.

How Much Does Medicare Part B Cost?

There are a few different costs that are involved in Medicare Part B, including a monthly premium, a potential late enrollment penalty, income-based charges and a deductible.

Part B premiums

Unlike Medicare Part A, which offers premium-free coverage for many people, everyone pays a monthly premium for Part B. Your Part B monthly premium will automatically be deducted if you receive Social Security, Railroad Retirement Board or Office of Personnel Management benefits.

If you do not receive automatic benefits, you will receive a bill for your Part B premium.

The cost of Medicare Part B is based on your income and tax filing status, but in general, most people pay the standard premium. In 2021, the monthly Part B premium is $148.50. Along with your standard monthly premium, if your income from your IRS tax return from two years prior is higher than a certain amount, you will also pay an extra Income Related Monthly Adjustment Amount (IRMAA).

Part B deductible

Along with your monthly premium, there is also a yearly deductible for Part B. In 2021, the deductible is $203. After meeting your yearly deductible, you will be responsible for 20% of the Medicare-approved amount for services and equipment under Part B. These include:

  • Doctor services, including when you’re in the hospital and seen by a doctor
  • Outpatient therapy
  • Durable Medical Equipment (DME)

The only exception to the deductible coinsurance of Part B is for preventive services; most people do not have to pay anything for preventive services as long as they are received from a Medicare provider.

Late enrollment penalty

You may have to pay a late enrollment penalty if you do not sign up for Part B when you are first eligible. The cost of the penalty is based on how many months you went without coverage even though you were eligible. Thus, the penalty will increase the longer you wait to have Part B coverage.

If you wait and do not enroll in Part B when you’re first eligible, your monthly premium can increase by 10% for each 12-month period that you wait. As an example, if you wait two years to enroll after you were first eligible, your penalty will be 20% of the standard premium price.

You can avoid a late enrollment penalty by signing up for Part B when you are eligible or by meeting certain conditions that allow you to sign during a Special Enrollment Period (SEP). A SEP is available to you if you, your spouse or a family member in the case of a disability, are working and you’re covered by a group or employer health plan. You also have eight months of a SEP in the event of any of the following situations:

  • The month after employment ends
  • The month after group health plan insurance based on current employment ends

If you need additional financial assistance paying your Part B premiums, Medicare Savings Programs may be able to help offset some or all of the costs. These programs are also available even if you are working and your income is higher than the listed limit.

What Does Medicare Part B Cover?

Medicare Part B covers two main types of services:

  • Medically necessary services: this includes the treatment, service or supplies you need for a medical condition as stipulated by standard medical practice. Medically necessary services would be things like a doctor’s office visit or a test to screen for illness.
  • Preventive services: any health care, such as vaccines, that you can receive to prevent an illness or detect it at an early stage for more effective intervention and treatment.

There are also specific services and supplies that Part B covers that include:

Clinical trials

Participation in clinical research trials include medical diagnosis and treatment such as tests, surgical treatments, medicine, or innovative forms of care.

Ground ambulance transportation

Ambulance transportation on the ground to go to a hospital, critical access hospital, or skilled nursing facility for medically necessary services. This can include for both emergency and non-emergency visits if you have a written doctor’s order that ambulance transportation is medically necessary. For instance, if a regular vehicle could pose a danger to your health.

Durable medical equipment (DME)

DME includes a variety of medically necessary supplies that have to be prescribed by your doctor. For instance, things like diabetic supplies, walking and mobility aids, hospitals beds, home IV supplies, oxygen equipment, wheelchairs and scooters are all covered by Part B.

Outpatient mental health coverage

  • Part B covers certain aspects of outpatient mental health care coverage the includes:
  • Yearly depression screening and wellness visit
  • Family counseling for coping with medical treatment
  • Individual and group psychotherapy (must be in the same state you get your treatment)
  • Testing for evaluation purposes
  • Partial hospitalization for mental health care, pending you meet certain qualifications under a doctor’s orders
  • Outpatient services for substance abuse
  • One-time preventive visit

Some outpatient prescription drugs

Most of your drug coverage will come through Medicare Part D, but Part B covers certain medications that you can’t give to yourself. Some of these types of drugs include:

  • Drugs used with DME, like a nebulizer
  • Antigens
  • Injectable osteoporosis drugs
  • Erythropoiesis-stimulating agents
  • Blood clotting factors
  • Injectable and infused drugs
  • End-stage-renal-disease drugs

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