If you miss your Medicare Initial Enrollment Period, you can enroll during either a Special Enrollment Period or the General Enrollment Period, but you may face late enrollment penalties that permanently increase your premiums.

A Special Enrollment Period allows penalty-free enrollment if you have qualifying job-based insurance. You have eight months to enroll after losing employer coverage or when you or your spouse stop working. Those under 65 who are Medicare-eligible due to disability may also qualify for an SEP if they have coverage through a family member working for a company with at least 100 employees.

The General Enrollment Period runs from January 1 through March 31 each year. During this time, you can enroll in both Medicare Part A and Part B. Coverage begins July 1, meaning you’ll have no Medicare coverage until that date if you enroll during GEP.

Missing your Initial Enrollment Period triggers late enrollment penalties. For Part B, you’ll pay an additional 10% of the standard premium for each full 12-month period you delayed enrollment. This penalty is permanent and added to your monthly premium for as long as you have Part B.