What is Medicare Part B?

Medicare part B is voluntary. All persons over age 65 and all persons enrolled in part A may enroll in part B by paying a monthly premium. The 2022 monthly premium is $170.10 (0r higher depending on your income). Part B covers medically necessary doctor’s services, outpatient care, home health services (those not covered by Part A), durable medical equipment and other medical services.

Part B also covers most preventative care. If your doctor accepts assignment (agrees to accept Medicare as full reimbursement), then typically you pay nothing for preventive services.

You can sign up for Medicare Part A and Part B when you apply for Social Security. Because applicants must pay a premium for Part B coverage, you can turn it down.

If you’re eligible at age 65, your Initial Enrollment Period (IEP) begins three months before your 65th birthday, includes the month you turn age 65, and ends three months after that birthday.

Note: Important Upcoming Change – Rules for 2023 and later: If you accept the automatic enrollment in Medicare Part B or if you sign up during the first three months of your IEP, your coverage will start the month you’re first eligible. Beginning January 1, 2023, if you sign up during the month you turn 65 or during the last three months of your IEP, your coverage starts the first day of the month after you sign up.

The following chart shows when your Medicare Part B becomes effective in 2022:

In 2022, if you sign up during this month of your IEP	Your Part B Medicare coverage starts
One to three months before you reach age 65	The month you turn age 65.
The month you reach age 65	One month after the month you turn age 65.
One month after you reach age 65	Two months after the month of enrollment.
Two or three months after you reach age 65	Three months after the month of enrollment.

The following chart shows when your Medicare Part B becomes effective in 2023:

Beginning in 2023, if you enroll in this month of your IEP	Your Part B Medicare coverage starts
One to three months before you reach age 65	The month you turn age 65.
The month you reach age 65, or one to three months after you reach age 65	The first day of the month after you sign up.

If you choose not to sign up for Medicare Part B but then decide to do so later, your coverage could be delayed. You may have to pay a higher monthly premium for as long as you have Part B. Your monthly premium will go up 10% for each 12-month period you were eligible for Part B, but didn’t sign up for it. This does not apply if you qualify for a “Special Enrollment Period” (SEP).

If you don’t sign up for Medicare Part B during your IEP, you have another chance each year to sign up during the “General Enrollment Period” (GEP) from January 1 through March 31. Your coverage starts the first day of the month after you sign up. Read Social Security’s publication Medicare for more information.