ACA Open Enrollment: Dates, Deadlines, and When Your Coverage Starts
Open Enrollment is the yearly window when most people can sign up for, or change, an ACA Marketplace health plan. The dates sound simple, but there are a few deadlines inside the window that decide when your coverage actually begins. This guide explains how they work so you can plan ahead.
When Does Open Enrollment Run?
On HealthCare.gov, Open Enrollment has typically run from November 1 to January 15. For the 2027 plan year, published guidance has pointed to the same window, November 1, 2026 through January 15, 2027. Federal rules and court decisions can change enrollment periods from year to year, so treat any date in an article, including this one, as something to confirm on HealthCare.gov before you act.
State-based Marketplaces run their own enrollment systems and may set different dates. Some states have historically kept enrollment open later than the federal deadline. If you live in a state with its own Marketplace, check that site for your exact schedule.
Why the Mid-December Deadline Matters
The last day of Open Enrollment is not the only date that counts. Your start date depends on when you finish enrolling:
- Enroll by mid-December (December 15 on HealthCare.gov) and coverage generally begins January 1.
- Enroll after that deadline, but before the window closes, and coverage generally begins on the first day of a later month, such as February 1.
That gap can mean a month or more without coverage if your current plan ends December 31. Waiting until the final week of the window is the most common way people end up with a delay.
What If You Miss Open Enrollment?
Outside Open Enrollment, you can usually enroll only if you qualify for a Special Enrollment Period, which is triggered by a qualifying life event such as losing other coverage, moving, getting married, or having a baby. These windows are limited in time, so it helps to act soon after the event. Our guide to Special Enrollment Periods explains which events may qualify.
What to Have Ready Before You Apply
Gathering information ahead of time makes enrollment faster and reduces mistakes:
- The names, birth dates, and Social Security numbers (or immigration document numbers) of everyone on the application
- An estimate of your household income for the coming year, including job income, self-employment income, and other sources
- Details of any current coverage, including employer coverage you could be offered
- A list of the doctors and prescriptions that matter most to you, so you can check plan networks and drug coverage
If You Already Have a Marketplace Plan
Plans, prices, and provider networks can change each year. If you do nothing, your plan may renew automatically, but it may no longer be the best fit or the cheapest option. Reviewing your options during Open Enrollment is a good habit even if you are satisfied with your current plan.
Where a Licensed Agent Can Help
A licensed agent can explain which dates apply where you live, what documents you need, and the plan options available in your area. You are never required to use an agent, and you can always enroll directly at HealthCare.gov.
Sources and Further Reading
Frequently Asked Questions
When does ACA Open Enrollment start and end?
On HealthCare.gov it has typically run from November 1 to January 15. State Marketplaces may use different dates, so confirm the schedule for your state.
What is the deadline to have coverage start on January 1?
On HealthCare.gov, enrolling by mid-December generally allows coverage to begin January 1. Later enrollments generally start on a later date.
Can I enroll after Open Enrollment ends?
Usually only if you qualify for a Special Enrollment Period, such as after losing other coverage or moving.
Do I have to use an agent to enroll?
No. You can enroll directly and for free at HealthCare.gov or through your state Marketplace.