Medicare is a federally funded program that provides health insurance to those 65 and over as well as some other groups. It consists of several different parts, including Part B.

Medicare Part B is the medical insurance portion of Medicare. In 2017, over 30 million people were enrolled in Part B.

If you’re enrolled in Part B, you’ll pay a monthly premium as well as other costs like deductibles and coinsurance.

Continue reading as we take a deeper dive into Part B, its costs, and who can enroll.

Medicare Part B is medical insurance. Together with Medicare Part A (hospital insurance), it makes up what’s called original Medicare.

Part B covers medically-necessary outpatient care. A service is considered medically necessary when it’s needed to diagnose or treat a specific condition or illness. Part B also covers some preventative care.

In some cases, you’ll be automatically enrolled in Medicare parts A and B when you turn 65. However, some people will need to sign up through the Social Security Administration (SSA).

When you’re enrolled in Part B, you’ll receive your Medicare card through the mail. This card should say “MEDICAL” on it and also have an effective date listed.

Let’s break down the costs associated with Part B in greater detail.

Monthly premium

If you have Part B, you’ll need to pay a monthly premium. The standard monthly premium for 2020 is $144.60.

However, the amount of this premium can increase based on your income. People with a higher income typically pay higher premiums. For 2020, income is calculated from your 2018 tax return.


A deductible is the amount that you have to pay out-of-pocket before Part B starts covering your outpatient services. For 2020, the Part B deductible is $198.


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


A copay is a set amount that you have to pay at the time you receive care. For Part B, you may have to pay a copay to a hospital if you use hospital outpatient services.

Out-of-pocket costs

Part B doesn’t cover some types of services like routine dental care or hearing aids. In these situations, you may have to pay for the entire cost of the outpatient services that you receive on your own. has a tool that lets you find out if a medical test or service is covered by Medicare.

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

  • people aged 65 and older
  • younger individuals with a disability
  • those who have end stage renal disease (ESRD) or Amyotrophic lateral sclerosis (ALS)

Eligibility for Part B depends on whether or not you’re eligible for premium-free Part A. Most people get premium-free Part A because they’ve paid Medicare taxes while working.

People who can get premium-free Part A include:

  • those who are 65 or older and eligible for, or currently receiving, Social Security or Railroad Retirement Board (RRB) retirement benefits
  • people below age 65 that can collect Social Security or RRB disability benefits
  • individuals currently getting regular dialysis or that have received a kidney transplant AND have applied for Medicare through the Social Security Administration.

People who can get premium-free Part A can also enroll in Part B when they’re first eligible for Medicare. If you’re not eligible for premium-free Part A, you have to meet the following guidelines to enroll in Part B:

  • be aged 65 or older
  • live in the United States AND be either a citizen or a permanent resident for at least five years

Enrollment in Medicare Part B

Some people are automatically enrolled in Part A and Part B. These people include:

  • those who are going to turn 65 and are already receiving Social Security or RRB retirement benefits
  • people who have a disability and have been receiving disability benefits from Social Security or the RRB for 24 months
  • individuals with ALS who are receiving disability benefits

Some people will have to sign up with the SSA to enroll in parts A and B. These people include those not already collecting Social Security or RRB retirement benefits at age 65 or those with ESRD.

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 their enrollment in Part B because they already have 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 chose to enroll in Part B during general enrollment, you may add a Part D (prescription drug coverage) 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 (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 time period after leaving employment or the group health plan.

If you don’t sign up 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 – March 31 each year).

With the late enrollment penalty, your monthly premium may go up 10 percent 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 two years to enroll in Part B. In this case, you’d pay your monthly premium plus 20 percent of the standard premium.

Part B covers a wide variety of medically-necessary outpatient services. Some examples include:

There are several things that Part B doesn’t cover. These include:

Medicare Part B is the medical insurance part of original Medicare. It covers medically-necessary outpatient services as well as some types of preventative 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 65, you’ll be enrolled in original Medicare automatically. Part B is voluntary. Some will need to sign up for original Medicare, so be sure to pay attention to important enrollment dates.

The information on this website may assist you in making personal decisions about insurance, but it is not intended to provide advice regarding the purchase or use of any insurance or insurance products. Healthline Media does not transact the business of insurance in any manner and is not licensed as an insurance company or producer in any U.S. jurisdiction. Healthline Media does not recommend or endorse any third parties that may transact the business of insurance.