Open enrollment for health insurance in the U.S. usually refers to two main things: Marketplace (ACA) plans and other types of coverage like employer plans and Medicare, each with its own window.

Key open enrollment dates (Marketplace / ACA)

For individual and family plans bought through the Health Insurance Marketplace (or directly from insurers but ACA-compliant):

  • For 2026 coverage in most states, open enrollment ran from November 1, 2025 to January 15, 2026.
  • Some states using their own exchanges had different end dates (for example, California, New York, New Jersey, Pennsylvania, etc. extended to around January 30–31, 2026 , while Idaho ended earlier on December 15, 2025).
  • Next season, for 2027 coverage, the federal window is expected to be November 1, 2026 through December 15, 2026 in many states, with some state exchanges allowed to extend slightly (but not past December 31).

If you missed this year’s open enrollment and don’t live in one of the states that extended it, you typically need a qualifying life event (like losing other coverage, moving, marriage, birth/adoption) to sign up through a special enrollment period.

Other health insurance “open enrollment” periods

Outside the ACA Marketplace, “open enrollment” can mean different windows:

  • Employer health plans (through work):
    Most employers set a once-a-year enrollment period , usually in the fall for coverage starting the next calendar year. Exact dates vary by employer and are not tied to federal ACA deadlines.
  • Medicare (for people 65+ or with certain disabilities):
    • Medicare Annual Enrollment Period: generally October 15 – December 7 each year, for changes to Medicare Advantage or Part D plans.
* Medicare **Advantage Open Enrollment Period:** usually **January 1 – March 31** each year, allowing certain plan changes if you are already in a Medicare Advantage plan.

Because each employer and some states can set their own windows, the safest move is to:

  1. Check your state Marketplace or HealthCare.gov if you buy your own plan.
  2. Check HR or your benefits portal if you get insurance through work.
  3. Check official Medicare sources if you’re on Medicare.

Quick forum-style take

“When is open enrollment for health insurance… and what if I miss it?”

  • For ACA/Marketplace plans: think early November through mid‑January , with a few states running a bit longer.
  • For job-based plans: look at your employer’s annual enrollment email or benefits site; many schedules cluster in October–November , but it’s employer-specific.
  • For Medicare: the “classic” window is Oct 15–Dec 7 each year, with an extra Jan–Mar window for Medicare Advantage changes.
  • If you’ve missed your window, check whether you qualify for a special enrollment period due to a life event, or whether programs like Medicaid (which is often year-round) might apply.

At the bottom of almost every official guide is the same core advice: don’t wait until the last day if you can help it—deadlines can shift slightly, states can announce last‑minute extensions, and site traffic gets heavy right at the end.

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Find out when open enrollment for health insurance happens for ACA Marketplace plans, job-based coverage, and Medicare, plus what to do if you miss the deadline and need coverage now.

Information gathered from public forums or data available on the internet and portrayed here.