ACA Open Enrollment 2027: Dates, Deadlines and the Subsidy Cliff

Open enrollment for 2027 marketplace coverage opens on November 1, 2026. If you already have a HealthCare.gov plan and do nothing, you will probably be re-enrolled automatically, and this is the year that is most likely to cost you. The enhanced premium tax credits that held premiums down from 2021 through 2025 expired on December 31, 2025, and Congress has not restored them for 2027. The 400% federal poverty level cutoff those credits had suspended is back. A plan that cost $95 a month this year can cost several hundred next year, and the renewal notice will not say so in those words.

The dates that govern 2027 coverage

On HealthCare.gov, open enrollment for 2027 coverage runs from November 1, 2026 through January 15, 2027. The deadline that decides whether you have insurance in January is earlier. December 15, 2026 is the last day to enroll in or change plans for coverage starting January 1, 2027. Enroll between December 16 and January 15 and coverage starts February 1 instead, which leaves a month uninsured. HealthCare.gov lists all three dates on its deadlines page.

Coverage does not begin until the first premium is paid, so a plan selected on December 15 with an unpaid bill is not coverage on January 1.

If your state runs its own exchange, your dates may differ. Federal rules at 45 CFR 155.410 let state exchanges set their own window within limits, and several run later. Entering your ZIP code at HealthCare.gov redirects you to your state's marketplace, and the dates there govern. Which states run their own is in our roundup of state and federal health insurance marketplaces.

Is open enrollment shorter this year?

Not on HealthCare.gov, despite a great deal of coverage saying otherwise. A 2025 CMS rule would have cut the federal window to November 1 through December 15 starting with plan year 2027. A federal court struck that provision down in City of Columbus v. Kennedy in June 2026, and CMS confirmed in a July 27, 2026 statement that "Open Enrollment at the Federally-facilitated Marketplace will begin on November 1, 2026 and end on January 15, 2027."

So articles and broker emails written before mid-2026 may still say the window closes December 15, and they are out of date. December 15 matters anyway, because it is the January 1 deadline.

What happens if you do nothing at all

You get re-enrolled. HealthCare.gov says it plainly: it will automatically re-enroll you if you have marketplace coverage in December and take no action to choose a plan or end coverage by December 15.

Auto re-enrollment is a reasonable safety net in a quiet year. 2027 is not a quiet year. Three things move under a renewed plan at once:

• Your plan's premium. Insurers refile rates annually, and 2027 filings came in high across most states.
• Your subsidy. The credit is pegged to the second-cheapest silver plan in your area, the benchmark. If the benchmark changes, your credit changes even when your plan does not.
• Your eligibility. With the enhanced credits gone, income that earned a credit in 2025 may earn nothing in 2027.

A renewal notice shows a new monthly figure. It does not show the cheaper plan two rows down, and it does not say your credit collapsed because your income crossed a line. Only reopening the application shows that.

The 400% cliff is back, and it is a cliff

From 2021 through 2025, no household paid more than 8.5% of income toward the benchmark silver plan, and there was no upper income limit at all. Both expired at the end of 2025. For 2027 the IRS has published the pre-2021 structure in Revenue Procedure 2026-26: a sliding scale that ends at 400% of the poverty line and offers nothing above it.

Eligibility for 2027 coverage is measured against the 2026 poverty guidelines. In the 48 contiguous states and DC, 400% of poverty is $63,840 for one person, $86,560 for a couple and $132,000 for a family of four. Alaska and Hawaii use higher figures, listed in the HHS poverty guidelines.

A hypothetical. A 45-year-old in an area where the benchmark silver plan costs $850 a month projects 2027 income of $63,000, just under 400% of poverty for one person. Their contribution is capped at 10.22% of income, about $537 a month, and the credit covers the remaining $313. The same person projecting $64,500 gets no credit and pays the full $850. An extra $1,500 of income costs roughly $3,750 in lost credits. How the credit is computed step by step is covered in our guide to marketplace premium subsidies.

What do the metal tiers actually buy you?

The metal name is not a quality rating. It is actuarial value: the share of total covered medical costs the plan pays across a standard population, before networks or specific benefits enter into it.

Plans may sit about two percentage points either side of those targets, so a silver plan can be a 68% or a 72% plan.

Cost-sharing reductions attach only to silver. If household income is at or below 250% of the poverty line, choosing silver gets you an upgraded version of that plan, with a lower deductible and a lower out-of-pocket maximum, at the same premium. The upgrade lifts silver's actuarial value to 73%, 87% or 94% depending on income. Pick bronze or gold and it is simply gone. For 2027, CMS has set the maximum out-of-pocket limit at $12,000 for self-only coverage and $24,000 for a family, with reduced caps of $4,000 for enrollees up to 200% of poverty and $9,600 for those between 200% and 250%.

That is the trade a $60 monthly premium saving is weighed against. Our deductible calculator puts it in dollars rather than tiers. A high-deductible bronze plan may pair with a health savings account, which has its own HSA contribution limits, and the HSA versus PPO comparison is built for that decision.

Check the network and the drug list before you enroll

Two documents decide whether a cheap plan is cheap for you, and neither is the premium.

The provider network is the list of doctors and hospitals the plan pays for. Marketplace plans skew toward narrow-network HMOs and EPOs, where out-of-network care is not covered outside emergencies and that spending does not count toward your out-of-pocket maximum. A doctor in network in 2026 can be out in 2027 under the same plan name.

The drug formulary is the list of medications the plan covers and the tier each sits on. A drug can move tiers, gain a prior authorization requirement, or drop off the list entirely between plan years. For anyone on a specialty medication, the formulary moves more money than the premium does.

Both are linked from the plan detail page during enrollment, and both belong to the plan year rather than the insurer. Checking a specific doctor and a specific prescription against the 2027 versions, rather than assuming last year's answer holds, is the step most people skip.

What if January 15 passes and you have no plan?

You need a Special Enrollment Period, which requires a qualifying life event. The categories HealthCare.gov recognizes:

1. Loss of other coverage, including losing job-based coverage, aging off a parent's plan at 26, losing Medicaid or CHIP, or reaching the end of COBRA.
2. Household changes, including marriage, a divorce that ends your coverage, birth, adoption or foster placement, or a death in the family.
3. Moves to a new ZIP code or county that change the plans available to you, including moving to the US from abroad or to and from school.
4. Other events, including gaining citizenship, leaving incarceration, gaining tribal membership, or an income change that alters your eligibility.

Most SEPs run 60 days from the event, and a loss of coverage can be claimed in the 60 days before it happens as well as after. Losing Medicaid or CHIP carries a longer window. Dropping coverage voluntarily, or losing it for non-payment, does not open an SEP, and neither does changing your mind about the plan you picked.

What people get wrong in open enrollment

Letting the renewal ride. The most expensive mistake available this year is treating auto re-enrollment as neutral. It is not, in a year when premiums, benchmarks and subsidy rules all moved at once.

Estimating income too low. The credit is advanced monthly against what you project for 2027, then reconciled on Form 8962 at filing. Project $58,000, earn $66,000, and you have crossed 400% of poverty, which means the entire advance credit is repaid with no repayment cap. Freelance and commission income is where this happens, because the figure is a forecast rather than a salary.

Shopping on premium alone. A $40 monthly saving is $480 a year. A deductible $3,000 higher, or an out-of-pocket maximum $4,000 higher, swamps it in any year you use the plan. Premium, deductible and out-of-pocket maximum are three numbers, not one.

Treating December 15 as soft. Missing it moves your start to February 1, and a month of exposure to a $12,000 out-of-pocket maximum is the real size of that error.

Assuming the same plan is the same plan. Insurers change networks, formularies, deductibles and service areas between plan years while keeping the name identical.

Where the marketplace is not the right route

The marketplace does not fit everyone, and claiming a credit you are not eligible for creates a bill later.

If your income is low enough for Medicaid. In expansion states, adults under 138% of the poverty line qualify, roughly $22,000 for one person and $45,500 for a family of four under the 2026 guidelines. Medicaid is not limited to open enrollment and can be applied for in any month. The marketplace application forwards you to your state agency when it looks like you qualify.

If you have an affordable employer offer. Where an employer plan meets minimum value and your share of the lowest-cost self-only premium is under 10.22% of household income in 2027, no premium tax credit is available to you or your family. Buying a marketplace plan is still possible at full price.

If you are eligible for Medicare. Turning 65 moves you to a different system with its own calendar and costs, set out in our guide to what Medicare premiums cost.

If you live in a non-expansion state and earn under 100% of poverty. This coverage gap leaves people ineligible for Medicaid and for premium tax credits at once. The marketplace has no fix for it.

What to do before December 15

• Log in to your marketplace account in early November and update projected 2027 income and household size before looking at plans.
• Read the renewal notice for the 2027 premium and the 2027 credit as two numbers, not one net figure.
• Compare the benchmark silver plan against your renewed plan, and check whether you fall under 250% of poverty and so qualify for cost-sharing reductions on silver.
• Look up every doctor you intend to keep and every prescription you take against the 2027 network and formulary for the plan you are considering.
• Write the premium, deductible and out-of-pocket maximum for your top two plans side by side before choosing.
• Complete enrollment and pay the first premium in time for January 1 coverage, then confirm the insurer shows you active.

If your income sits near 400% of the poverty line, the first number to check is not the premium. It is whether your 2027 projection lands above or below $63,840 for one person, because that line decides whether any of the rest is subsidized.