Most people get Medicare Part A and Part B when first eligible (usually when turning 65). Generally, there are risks to signing up later, like a gap in your coverage or having to pay a penalty. However, in some cases, it might make sense to sign up later.

Initial Enrollment Period, or IEP: This is your first chance to sign up for Medicare. Generally, this is when you turn 65. It lasts for seven months, starting three months before you turn 65, and ending three months after the month you turn 65.

You can sign up for Part A any time after you turn 65. Your Part A coverage starts six months back from when you sign up or when you apply for benefits from Social Security. Coverage can’t start earlier than the month you turned 65.

After your IEP ends, you can only sign up for Part B and Premium-Part A during one of the other enrollment periods:

 

 

General Enrollment Period: You can sign up between January 1 and March 31 each year. Your coverage starts the month after you sign up. You might pay a monthly late enrollment penalty, if you don’t qualify for a Special Enrollment Period.

Special Situations (Special Enrollment Period): After your first chance to sign up (Initial Enrollment Period), there are certain situations when you can sign up for Part B (and Premium-Part A) without paying a late enrollment penalty. A Special Enrollment Period is only available for a limited time. If you don’t sign up during your Special Enrollment Period, you’ll have to wait for the next General Enrollment Period and you might have to pay a monthly late enrollment penalty.

Some examples of special situations are losing Medicaid coverage, missing your chance to sign up because you were impacted by a natural disaster, or missing your chance to sign up because you got inaccurate or misleading information from your health plan or employer.

Situations that don’t qualify for a Special Enrollment Period include your COBRA or retiree coverage ending; you missed your eight-month window to sign up when you stopped working or lost job-based coverage; or you lose your Marketplace coverage.