Medicare Part B Eligibility 

Generally, you’re eligible for Medicare Part B  if you meet 1 or more of the following qualifications:

• You are 65 or older and either you or your spouse worked and paid Medicare taxes for at least 10 years.
• You are a U.S. citizen or a lawfully present resident who’s lived in the United States for at least 5 years.
• You’re under 65 but you’ve been receiving Social Security Disability Insurance (SSDI) for at least 24 months. 
• You’re under 65 and have ALS (Lou Gehrig’s disease) or end-stage renal disease (ESRD). 

There are 3 main opportunities to enroll in Medicare Part B:

• Initial Enrollment Period (IEP) : This is a 7-month window around your 65th birthday (3 months before, your birthday month, and 3 months after).
• Special Enrollment Period (SEP) : If you’re still working and have health insurance through your job, you can wait to sign up for Part B without penalty. Once you stop working, you’ll have 8 months to enroll.
• General Enrollment Period (GEP): Missed the other windows? You can sign up between Jan. 1 and March 31 each year, but your coverage won’t start until July—and you might have to pay a late fee.

Most people pay a monthly premium for Part B. The standard amount changes each year, and if you have a higher income, you might have to pay a bit more. For 2025, the standard Medicare Part B premium is $185.

If you don’t sign up for Part B when you’re first eligible and you don’t have other qualifying health coverage—like coverage through a current employer—you’ll pay a penalty for every year you delayed enrollment. And you’ll pay this extra amount every month for as long as you have Part B.

Understanding Medicare Part B eligibility is an important step in getting the healthcare coverage you need. If you’re ready to take the next step, be sure to review your options and enroll in Part B on time to avoid any late enrollment penalties.