Special enrollment period
Updated for plan year 2026
In plain terms
A Special Enrollment Period (SEP) is a window to enroll in or change a marketplace plan outside the normal open enrollment, triggered by a qualifying life event. Losing other coverage, moving, marrying, or having a baby can each open one. Most SEPs last 60 days from the event, and some let you enroll up to 60 days before a known change, such as a coverage loss you can see coming. Miss the window, and you generally wait for the next open enrollment unless another event occurs.
A plain example
Your job-based coverage ends June 30. That loss opens a special enrollment period running from 60 days before to 60 days after, so you can pick a marketplace plan as early as May or as late as the end of August. Enroll in July and your new coverage starts August 1, the first of the month after you choose.
Why it matters
Outside open enrollment, a special enrollment period is usually the only way onto a marketplace plan, and the 60-day clock is unforgiving. Knowing an event qualifies, and acting inside the window, is what stands between you and a months-long wait for the next open enrollment.
A common point of confusion
Not every life change qualifies, and some have conditions. Voluntarily dropping coverage you could have kept doesn't open a window, and the move and marriage SEPs generally require that you already had qualifying coverage beforehand.