Original Medicare is made up of parts A and B. Part B is medical insurance that covers outpatient and preventive services. If you enroll in Part B, you will have to pay a monthly premium, a deductible, and coinsurance.

Medicare consists of several different parts, including Part B. Medicare Part B is medical insurance and covers medically necessary outpatient care and some preventive care.

Together with Medicare Part A (hospital insurance), it makes up Original Medicare.

If you’re enrolled in Part B, you’ll pay a monthly premium, as well as other costs like a deductible and coinsurance. Continue reading to take a deeper dive into Part B, its costs, and more.

If you have Part B, you’ll need to pay a monthly premium. The standard monthly premium for 2024 is $174.70.

The amount of this premium can increase based on your income. People with a higher income typically pay what’s known as an income-related monthly adjustment amount (IRMAA). For 2024, your IRMAA is calculated from your 2022 tax return.

A deductible is an amount that you have to pay out of pocket before Part B starts covering your outpatient services. For 2024, the Part B deductible is $240.

Coinsurance is the percentage that you pay after you’ve met your deductible. For most services covered by Part B, you’ll pay 20% of the cost.

The following individuals can enroll in Original Medicare (parts A and B):

Eligibility for Part B depends on whether you’re eligible for premium-free Part A. Most people get premium-free Part A because they’ve paid Medicare taxes while working.

Enrolling in Medicare Part B

Some people will get automatically enrolled in Part A and Part B, including those who:

  • are going to turn 65 years old and are receiving Social Security or Railroad Retirement Board (RRB) benefits
  • have a disability and have been receiving disability benefits from Social Security or the RRB for 24 months

Other people will have to sign up with the Social Security Administration to enroll in parts A and B. This includes people who are not already collecting Social Security or RRB retirement benefits at age 65 years or those with ESRD or ALS.

For people who are automatically enrolled, Part B coverage is voluntary. That means that you can choose not to have it.

Some people may wish to delay enrollment in Part B because they already have other health coverage. Whether or not you choose to delay enrolling in Part B can depend on the specific health insurance plan that you have.

Deadlines for enrolling in Medicare Part B

Here are some important dates to keep in mind for enrolling in Part B:

  • Your 65th birthday: The initial enrollment period is a 7-month time span. It includes the month of your 65th birthday and the 3 months before and after. You can enroll in parts A and B at any point during this time.
  • January 1 through March 31: This is general enrollment. If you didn’t enroll in Part B during initial enrollment, you can do so at this time. You may need to pay a late enrollment penalty.
  • April 1 to June 30: If you enrolled in Part B during general enrollment, you may add a Part D (prescription drug) plan during this period.
  • October 15 to December 7: This is the open enrollment period. If you want to switch from Original Medicare (parts A and B) to a Part C (Medicare Advantage) plan, you can do so. You may also switch, add, or remove a Part D plan.
  • Special enrollment: You may have employer-provided coverage in a group health plan. If so, you can sign up for parts A and B at any time during plan coverage or in the 8-month special enrollment period after leaving employment or the group health plan.

If you don’t sign up for Part B when you’re first eligible, you may be required to pay a late enrollment penalty when you do choose to enroll. Additionally, you’ll need to wait until the general enrollment period (January 1 through March 31 each year).

With the late enrollment penalty, your monthly premium may go up 10% of the standard premium for each 12-month period that you were eligible but didn’t enroll. You’ll continue to pay this penalty for as long as you’re enrolled in Part B.

For example, let’s say that you waited 2 years to enroll in Part B. In this case, you’d pay your monthly premium plus 20% of the standard premium.

Medicare Part B is the medical insurance part of Original Medicare. It covers medically necessary outpatient services as well as some types of preventive care.

You’ll have to pay a monthly premium for Part B. Other potential costs include deductibles, coinsurance, and copays. You may also need to pay out-of-pocket for services that aren’t covered under Part B, like dental care and eye exams.

If you already collect Social Security benefits when you turn age 65 years, you’ll be enrolled in Original Medicare automatically. Part B is voluntary.

Other people will need to sign up for Original Medicare, so you may want to pay attention to important enrollment dates.