Open Enrollment 2027: Calendar and Key Deadlines for Your ACA Coverage

Open Enrollment for 2027 coverage is the most consequential enrollment window in years. The Inflation Reduction Act subsidies expired on December 31, 2025, and 2027 is the first full year where carriers have repriced every plan with that change fully baked in. Networks have shifted. Benchmark premiums have moved. Auto-renewing into your 2026 plan without checking is the single most expensive mistake you can make this winter.

This page lays out every deadline you need: federal Marketplace dates, state-specific extensions, coverage start dates by enrollment date, the auto-renewal risk, and a pre-Open Enrollment checklist that takes about an hour to work through.

The dates at a glance

Sources: Centers for Medicare & Medicaid Services (CMS) Open Enrollment notice and Kaiser Family Foundation state Marketplace tracker.

The critical dates: November 1 through January 31

November 1, 2026 is the first day you can enroll in or change a 2027 Marketplace plan. The HealthCare.gov shopping tool turns on overnight, and state Marketplaces follow the same schedule. Plans become viewable, subsidy estimates use the 2027 benchmark, and enrollments can be submitted.

December 15, 2026 is the universal deadline for January 1, 2027 coverage. Every Marketplace, every state, every insurance company honors this date. If you submit your application by 11:59 PM local time on December 15 and pay your first premium by the carrier’s binding deadline, your plan is active on January 1.

January 15, 2027 is the federal Open Enrollment deadline. HealthCare.gov, Pennie, and Connect for Health Colorado close at this point. If you enroll between December 16, 2026 and January 15, 2027, your coverage starts February 1, 2027.

January 23, 2027 is the Massachusetts Health Connector deadline. Massachusetts has historically aligned closer to the federal calendar than other state Marketplaces.

January 31, 2027 is the deadline for the majority of state-run Marketplaces, including the largest by population (California, New York, New Jersey). Coverage from a January 16 to January 31 enrollment typically begins March 1, 2027, which means a full February without insurance unless your prior plan also covered February.

Coverage start dates by enrollment date

The Marketplace works on a strict effective-date schedule. Where you enroll matters less than when.

• November 1, 2026 to December 15, 2026 → coverage starts January 1, 2027
• December 16, 2026 to January 15, 2027 → coverage starts February 1, 2027
• January 16, 2027 to January 31, 2027 (state extensions only) → coverage starts March 1, 2027

A few exceptions: newborns and adoptions during a Special Enrollment Period are usually retroactive to the date of birth or placement. Loss-of-coverage SEPs sometimes allow next-day coverage in state-run systems. Your agent or the Marketplace will confirm the exact effective date when you submit.

Want help locking in January 1 coverage? Talk to a licensed agent — free, bilingual, no obligation.

State-run Marketplaces versus HealthCare.gov

If you live in one of the 19 states (plus DC) that runs its own ACA Marketplace, you have more flexibility than people in HealthCare.gov states. Here is the practical impact.

You can enroll later. Most state Marketplaces give you until January 31, 2027. If life gets in the way during December, you have an extra two weeks to act.

Your coverage start date is the same. A state extension does not move the effective dates. December 15 still locks January 1. January 15 still triggers February 1. January 31 still triggers March 1.

State Marketplaces sometimes have richer subsidies. California, New Jersey, Massachusetts, Colorado, Connecticut, New York, and Washington have layered state-funded subsidies on top of the federal premium tax credit. Even with the IRA expiration at the federal level, residents in these states may see less price impact for 2027.

Customer service differs. State Marketplaces often have shorter wait times during the December crunch than HealthCare.gov. If you need to call the Marketplace directly, the wait at a state line is usually 5 to 15 minutes versus 45 to 90 minutes federally in the second week of December.

For a deeper look at specific state Marketplaces, see our city guides for Los Angeles, CA, the Bronx, NY, Newark, NJ, and Denver, CO.

Why enrolling early matters

The two months between November 1 and December 15 are not equally good. The first three weeks are the cleanest part of the season, and every week after that gets harder.

Agent availability. A licensed agent in mid-November can give you a full 45-minute consultation, compare 5 to 8 plans against your specific doctors and prescriptions, and answer follow-up questions over a few days. The same agent in mid-December is rotating through 20+ clients per day, often unable to schedule a careful comparison until January.

Verification flags. If your application gets flagged for income or immigration verification, the Marketplace gives you 90 days to respond. If you enroll on December 14 and get flagged, you might miss your January 1 effective date. If you enroll on November 10 and get flagged, you have 30 days to clear it before the January 1 deadline.

Network confirmation. Doctor networks change every January. The plan that covered your primary care physician in 2026 may have dropped that provider for 2027. Confirming networks takes a few minutes per plan in November and grows harder as carrier service lines saturate in December.

Latino community enrollment. Historical CMS data shows enrollment among Spanish-speaking households peaks in the last two weeks of Open Enrollment, with a corresponding spike in errors. Enrolling earlier reduces that risk substantially.

Auto-renewal: why not to trust it

If you are already enrolled in a 2026 Marketplace plan and do nothing by December 15, 2026, the Marketplace will renew you automatically. This sounds convenient. For 2027, it is dangerous.

Three things change automatically in an auto-renewal:

1. Your plan’s 2027 price. Carriers reprice every plan each year. The premium that was $389 in 2026 is rarely $389 in 2027.
2. Your subsidy. The premium tax credit is calculated against the second-lowest-cost Silver plan in your area, which moves every year. Even if your income is identical, your subsidy can shift up or down.
3. The benchmark itself. With IRA expiration fully baked into 2027 rates, the benchmark in many counties has changed materially.

What does not change automatically: your income estimate. The Marketplace carries forward whatever income figure you last reported. If your income went up in 2026, your auto-renewed subsidy is overstated and you will owe at tax time. If your income went down, you are leaving money on the table all year.

The cleanest move is to log in between November 1 and December 1, update your income estimate, and either confirm your plan or compare against alternatives. Fifteen minutes saves hundreds of dollars for most households.

Changes for 2026 and 2027

IRA subsidy expiration is now fully priced in. The enhanced premium tax credits expired on December 31, 2025. The 2026 plan year was the first year of impact, but carriers had to submit 2026 rates in mid-2025 with incomplete information about how enrollment would shift. By the time 2027 rates were filed, carriers had a full year of post-expiration enrollment data, and the 2027 prices reflect a more complete adjustment. Most counties will see noticeable rate movement compared to 2026.

DACA APTC rollback timing. A court ruling effective June 30, 2026 removed premium tax credit eligibility for DACA recipients with household incomes above 138 percent of the Federal Poverty Level. DACA recipients below that threshold may still qualify for Medicaid in states that have expanded the program. For 2027 Open Enrollment, DACA applicants should confirm their current eligibility before relying on the HealthCare.gov subsidy estimate, since the rule is still being litigated.

Network changes. Several large insurance carriers narrowed their provider networks during 2026 in response to medical cost pressure. If you have a relationship with a specific doctor, hospital, or specialist, confirming that provider is still in network for 2027 is critical before you finalize a plan.

Prescription tier changes. Drug formularies are also re-filed each year. A medication that was tier 2 in 2026 may be tier 3 in 2027, doubling your out-of-pocket cost for that prescription. Pull your prescription list before shopping and check tier placement on each plan.

Your pre-Open Enrollment checklist

Spend an hour in late October or early November on these steps. You will save days of stress in December.

1. Gather your 2026 plan documents. Pull your insurance card, your most recent Explanation of Benefits, and any letters from your insurer about 2027 changes.
2. Confirm your 2026 income. Pull your most recent pay stubs, your 2025 tax return, and a rough 2027 income estimate.
3. List your doctors. Write down every provider you have seen in the past 12 months, including specialists, primary care, dental, and vision if relevant.
4. List your prescriptions. Write down every medication you take regularly, with dose and frequency.
5. Note any upcoming medical events. Surgery, pregnancy, planned specialist visits — these all affect which metal tier makes sense.
6. Check your state’s Marketplace. Confirm whether you use HealthCare.gov or a state Marketplace.
7. Pick your enrollment path. Decide whether to enroll directly, work with a licensed agent, use a Navigator, or call the Marketplace.
8. Schedule the appointment. If using an agent, book a slot in the first two weeks of November. Agents fill up fast.

Common timing mistakes

Waiting until December 14 because that is “before the deadline.” December 14 is too late for a careful comparison. Most agents are slammed, and verification holds may not resolve in time for January 1.

Assuming auto-renewal is fine. Auto-renewal is fine if your situation is genuinely unchanged and the benchmark plan in your area is unchanged. For 2027, both conditions are unlikely.

Missing December 15 because you were enrolling on a state-run Marketplace. State Marketplaces extend the close of Open Enrollment, but December 15 is still the cutoff for January 1 coverage everywhere. A January 5 enrollment, even on Covered California, starts February 1.

Not paying the first premium. Enrollment alone does not activate coverage. You must pay the binding first premium by the insurer’s deadline, usually within 7 to 30 days of enrollment. Set up auto-pay during the application.

Reporting old income. The Marketplace asks for projected 2027 income, not 2026 actuals. A stale income figure produces a stale subsidy.

Related guides

• How to apply for Obamacare
• Who qualifies for Obamacare
• Obamacare income limits
• The Marketplace overview

Ready to enroll for 2027? Let’s start your application together. Free, bilingual, no obligation.

Last updated: May 20, 2026.

Disclaimer: This page is for informational purposes only and does not constitute professional advice. Open Enrollment dates, premium tax credit rules, and Marketplace policies can change. Always confirm current deadlines with the relevant Marketplace and speak with a licensed insurance agent for guidance specific to your situation.