For ACA Marketplace plans, open enrollment usually runs from November 1 to January 15 in most states, with coverage starting January 1 if you enroll by December 15. Employer plans set their own annual window (often in the fall). Outside these windows, you can only enroll if you have a qualifying life event that triggers a Special Enrollment Period.
Health insurance has a calendar, and missing it can leave you uncovered for a year. Here’s exactly when you can enroll — and the exceptions that let you in outside the window.
ACA Marketplace open enrollment
In most states, Marketplace open enrollment runs roughly November 1 to January 15:
- Enroll by December 15 → coverage usually starts January 1.
- Enroll December 16–January 15 → coverage usually starts February 1.
States that operate their own exchanges sometimes extend the deadline, so confirm your state’s dates.
Employer plan open enrollment
If you get insurance through work, your employer sets its own annual open enrollment window — commonly a few weeks in the fall. This is when you pick or change your plan, add dependents, or enroll in an FSA/HSA. Your HR department sets and announces the exact dates.
Medicare (different calendar)
Medicare’s annual open enrollment runs October 15 to December 7 — separate from everything above. If you’re 65+ or on Medicare, that’s your window.
If you miss the window: Special Enrollment
Outside open enrollment, you can only get a Marketplace or employer plan if you have a qualifying life event, which opens a 60-day Special Enrollment Period:
- Losing other coverage (job loss, aging off a parent’s plan, COBRA ending)
- Moving to a new area
- Marriage or divorce
- Having or adopting a child
- Certain income changes
Medicaid and CHIP have no enrollment window — you can apply any time and enroll immediately if you qualify.
The bottom line
Mark November 1–January 15 for the Marketplace (enroll by December 15 for January 1 coverage), watch your employer’s fall window, and remember that a qualifying life event is your way in if you miss it. When in doubt, check your state’s marketplace for exact deadlines.
Frequently asked questions
What if I miss open enrollment?
You generally can’t buy a Marketplace plan until the next open enrollment — unless you have a qualifying life event (losing coverage, moving, marriage, a new baby) that opens a 60-day Special Enrollment Period. Medicaid and CHIP enroll year-round.
When does coverage start if I enroll during open enrollment?
On the Marketplace, enrolling by December 15 typically starts coverage January 1. Enrolling between December 16 and the January deadline usually starts coverage February 1.
Do state marketplaces have different dates?
Yes. Some states that run their own exchanges extend the deadline past January 15. Always check your state’s marketplace for the exact dates, since they can differ from the federal schedule.
Leave a Reply