ACA Open Enrollment 2027: Key Dates and Deadlines

Open Enrollment is the one stretch of the year when anyone can buy, switch, or drop an Affordable Care Act (ACA) Marketplace plan without needing a qualifying life event. For 2027 coverage, the dates have caused more confusion than usual. A 2025 federal rule had planned a shorter window, and many articles still repeat the old schedule. This guide lists the dates as published by HealthCare.gov and several state exchanges. It also explains what each deadline controls and what your options are once the window closes.

2027 Open Enrollment Dates on HealthCare.gov

If your state uses the federal Marketplace at HealthCare.gov, these dates apply to you. According to HealthCare.gov's official dates and deadlines page, these are the key dates for 2027 coverage:

The days of the week above match the dates MNsure, Minnesota's exchange, published in its 2027 Open Enrollment announcement. Both deadlines fall close to the holidays, so plan to finish your application well before the last day.

Why You May Have Seen "December 15" as the Final Deadline

In June 2025, CMS finalized the Marketplace Integrity and Affordability rule. For exchanges on the federal platform, it said Open Enrollment would run November 1 through December 15, beginning with plan year 2027. That is why some older articles describe December 15, 2026 as the end of Open Enrollment.

HealthCare.gov's current dates and deadlines page lists January 15, 2027 as the last day of Open Enrollment for 2027 coverage. When sources disagree, go with the official HealthCare.gov or state exchange page. Either way, December 15 is still the deadline that matters most, because it is the last day to pick a plan that starts January 1.

2027 Open Enrollment Dates at State-Run Exchanges

Some states run their own Marketplace and set their own Open Enrollment dates. The table below covers state exchanges that had published 2027 dates on their official sites when we reviewed them. If your state isn't listed, check its exchange directly. Our state health insurance directory can help you find plans in your state.

Two things stand out. First, a longer window doesn't mean a later January 1 deadline everywhere. Colorado, Connecticut, and Minnesota all end Open Enrollment on January 15 but still require you to pick a plan by December 15 for January 1 coverage. Second, Connecticut opens earlier than the federal Marketplace, on October 23, 2026. If you live in a state with its own exchange, the exchange's website is the final word on your dates.

What the December 15 Deadline Controls

December 15 isn't just a date for coverage to start. On HealthCare.gov, it also decides whether you or the system picks your 2027 plan.

Automatic Re-Enrollment

HealthCare.gov says it will automatically re-enroll you if you have Marketplace coverage in December and don't choose a plan or end your coverage by December 15. You might be placed back in your current plan or in a different plan from the same insurer. If your insurer isn't offering Marketplace plans for 2027, you could be matched with a plan from a different company.

Auto-renewal keeps you covered, but it doesn't mean you are in the best plan. Premiums, provider networks, and drug lists can change each year. Our post on proposed 2027 ACA premium increases explains why prices are expected to move for 2027.

Your Tax Credit Is Based on 2027 Income

Your premium tax credit is based on your estimated household income for the coverage year, not what you earned in past years. HealthCare.gov warns that if you don't update your income and household information, you could get less savings than you qualify for. You could also get more than you qualify for and have to pay back the difference when you file your federal taxes.

Before December 15, update your application with your expected 2027 income, household size, and any changes in job-based coverage offers. For a rough idea of how income affects your savings, try our APTC subsidy calculator. Then confirm your actual amount on HealthCare.gov or your state exchange.

A Hypothetical Timeline: Enrolling Early vs. Late

The example below is hypothetical and only shows how the HealthCare.gov deadlines work. It is not based on a real person.

Your Plan Isn't Active Until You Pay

Choosing a plan by the deadline is only the first step. HealthCare.gov explains that your coverage won't start until you pay your first premium, and that you pay premiums directly to the insurance company, not the Marketplace. If you don't pay, the insurer could end your coverage. After you enroll, look for the insurer's payment instructions and pay the first bill before the coverage start date.

What Happens After Open Enrollment Ends?

After the last day of Open Enrollment, HealthCare.gov says you can enroll in or change plans only if you qualify for a Special Enrollment Period. You still have a few options.

Special Enrollment Periods

A Special Enrollment Period (SEP) opens after certain life events. For most events, you qualify if the event happened in the past 60 days or if you expect to lose coverage in the next 60 days. If you lost Medicaid or CHIP coverage, HealthCare.gov says you may qualify if the loss was in the past 90 days. Qualifying events fall into these main groups:

• Changes in household: getting married, having or adopting a child, divorce or legal separation, or a death in the household.
• Changes in residence: moving to a new ZIP code or county, or moving to the U.S.
• Loss of health coverage: losing job-based coverage, an individual plan, Medicaid or CHIP, Medicare Part A, or coverage through a family member.
• Employer help with individual coverage: being offered an individual coverage HRA or a QSEHRA.
• Other events: such as gaining tribal membership or citizenship, being released from incarceration, or being affected by a natural disaster.

You must attest that the information on your application is true, and you may have to send documents that show you lost coverage. HealthCare.gov says that if you don't provide acceptable documents, you won't qualify for the SEP.

Medicaid and CHIP Year-Round

Medicaid and the Children's Health Insurance Program don't use Open Enrollment. According to HealthCare.gov, you can apply for Medicaid and CHIP any time of year. If your income is low or has dropped, apply even if Open Enrollment has ended. For other ways to lower costs, see our guide to affordable health insurance.

Your 2027 Open Enrollment Checklist

Use this list to finish well before the deadlines:

1. Find your exchange and its dates. Find out whether your state uses HealthCare.gov or its own exchange, then note that exchange's January 1 deadline.
2. Gather your information. HealthCare.gov offers a pre-application checklist of the documents and details to have on hand.
3. Update your 2027 income estimate. This sets your premium tax credit. Pre-check your savings with our subsidy calculator.
4. Compare total costs, not just premiums. Look at deductibles, out-of-pocket maximums, and copays across metal tiers. Our average cost of health insurance page shows typical premiums by tier. For a step-by-step method, read how to compare health insurance plans.
5. Check doctors and prescriptions. Confirm your providers are in network and your medications are on the plan's drug list for 2027.
6. Choose by December 15 (or your state's January 1 deadline) and pay your first premium.

For more pitfalls to avoid, including missed deadlines, see our common health insurance mistakes guide. If an insurance term is unfamiliar, look it up in our health insurance glossary.

Conclusion

For most people, 2027 Open Enrollment comes down to three dates. It opens November 1, 2026. December 15, 2026 is the last day to choose a plan that starts January 1. January 15, 2027 is the last day to enroll at all on HealthCare.gov. State exchanges can differ, so confirm your dates on your exchange's official website. Don't count on auto-renewal. Update your income, compare plans, and pay your first premium so your 2027 coverage starts when you expect. If your situation is complicated, check with HealthCare.gov, your state exchange, or a licensed agent.

Frequently Asked Questions

1. When is ACA Open Enrollment for 2027 coverage?
   On HealthCare.gov, Open Enrollment for 2027 coverage runs from November 1, 2026 through January 15, 2027. States that run their own exchanges can set different dates, so check your state exchange's website.
2. What is the deadline for coverage starting January 1, 2027?
   On HealthCare.gov, you must enroll in or change plans by December 15, 2026 for coverage that starts January 1, 2027. Some state exchanges use a different date. For example, Covered California's deadline for January 1 coverage is December 31.
3. What happens if I enroll between December 16 and January 15?
   On HealthCare.gov, plans chosen from December 16, 2026 through January 15, 2027 start on February 1, 2027.
4. Will my Marketplace plan renew automatically if I do nothing?
   Usually, yes. HealthCare.gov will automatically re-enroll you if you have Marketplace coverage in December and don't choose a plan or end your coverage by December 15. You may be placed in your current plan, a different plan from the same insurer, or a plan from another company if your insurer leaves the Marketplace. Update your income so your tax credit is correct.
5. Can I get health insurance after Open Enrollment ends?
   Yes, if you qualify for a Special Enrollment Period, usually within 60 days of a qualifying life event such as losing coverage, moving, marriage, or having a baby. You can apply for Medicaid and CHIP any time of year. See our affordable health insurance guide for other low-cost options.