What is Medicare Part B?

Medicare Part B (medical) is Original Medicare that you get through the federal government. Your decision about signing up for Medicare Part B depends on your personal preferences and your other health insurance.

When to enroll in Medicare Part B

If you have private insurance

If you have a private insurance plan, contact your insurance agent. You may not need to sign up for Medicare Part B at this time.

If you, spouse or a family member is disabled

If you or your spouse (or family member if you're disabled) is still working and has employer-provided coverage, your employer or union benefits administrator may be able to help you decide if it's to your advantage to delay enrolling in Part B. You can enroll in Part B any time you have current employer health coverage. COBRA and retiree health coverage don't count as current employer coverage.

Three ways to apply for Medicare Part B

If you're nearing 65 and you're not receiving Social Security or Railroad Retirement Board (RRB) benefits, you'll want to apply for Part B (if you need it) as soon as you can. There are three ways to apply:

If you already receive Social Security or RRB benefits, you don't need to do anything. You'll receive a Medicare red-white-and-blue card about three months before your 65th birthday. If disabled, you'll receive your card during your 25th month of disability.

If you don't want Medicare Part B

Follow the instructions that come with the red-white-and-blue card and send the card back. But think carefully before you do. If you don't sign up for Part B when you are first eligible and you need it later, you will probably have to pay a penalty. If you keep the card, you keep Part B and will pay Part B premiums.

What's the Medicare Part B penalty?

If you don't sign up for Part B when you are first eligible for Medicare, you may be penalized depending on your coverage being creditable or not.

Creditable coverage is coverage provided by an employer group or union that offers benefits comparable to Original Medicare.

If you have creditable coverage

There is no penalty. If your creditable coverage is through an employer, you'll have eight months to sign up for Part B without a penalty after your employment ends.

If you don't have creditable coverage

If you don't have creditable coverage and you miss your enrollment period for Medicare Part B, a late-enrollment fee will be added to your monthly premium once you do enroll. This fee will continue for as long as you have Medicare. Your Part B monthly premium may go up 10% for each full year that you could have had Part B.

Special situations for Medicare eligibility

In some situations you may be eligible for Medicare before you turn 65 or you may need some parts of Medicare to keep your current health plan or add other coverage.

If you have a particular disease

  • If you have amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease, you automatically get Part A and Part B the month your disability benefits begin.
  • If you have End-Stage Renal Disease (ESRD) you can apply for Part A and Part B.

If you live outside the U.S.

  • If you live in Puerto Rico and get benefits from Social Security or the RRB you'll automatically get Part A. If you want Part B, you'll need to apply for it.

If you have alternative Medicare coverage

  • If you have Part A and TRICARE (insurance for active duty military or retirees and their families) you must have Part B to keep your TRICARE coverage unless the service member who carries the coverage is on active duty.

Remember, you must be enrolled in Medicare Part A and Medicare Part B and continue to pay your Part B premium to enroll in a Medicare Advantage or Medigap plan.