Four reasons to not wait until January to enroll in an ACA health plan

Open enrollment for individual/family health coverage begins on November 1 and continues until at least January 15 in nearly every state. (Idaho ends its open enrollment period in December, but Idaho also starts early, allowing people to enroll starting in mid-October.)¹

For several years, open enrollment ended in mid-December. So the fact that enrollment now continues until at least mid-January in nearly every state does give people some extra wiggle room during the busy holiday season. But for most people, December 15 is still the soft deadline to keep in mind. In most states, that’s the last day you can enroll in coverage that will take effect January 1. (Some state-run Marketplaces have a later deadline. Check with your state’s Marketplace to confirm.) And that’s important for several reasons.

1. Currently uninsured? Delaying your enrollment will mean no coverage in January.

If you aren't already enrolled in ACA-compliant coverage, the open enrollment period that starts November 1 and ends in mid-January (in most states) is your chance to change that for the coming year. But if you wait until after December 15 to enroll, you won’t have coverage in place when the new year begins. Instead, you’ll be waiting until February 1 for your coverage to begin. (As noted above, some state-run Marketplaces have a later deadline to enroll in a plan with a January 1 effective date, but it’s December 15 in most states.)

2. Currently uninsured or enrolled in a non-Marketplace plan? Delayed enrollment might mean missing out on free money.

If you considered Marketplace coverage in the past and found it to be unaffordable, you might currently be uninsured or enrolled in a plan that isn’t regulated by the ACA. Or you might have opted to buy ACA-compliant coverage outside the exchange, if you weren’t eligible for premium tax credits (subsidies) the last time you looked.

But most Marketplace enrollees (87% in 2026) qualify for subsidies that average $650/month, offsetting the majority of the average premium. And more than 6.2 million people were paying less than $10/month for their coverage in 2026.²

You may be eligible for Marketplace subsidies, but you can’t claim them until you’re enrolled in a Marketplace plan.

If you’re eligible for a subsidy, but you wait until after December 15 to enroll, you’ll leave that subsidy money on the table for January, since your coverage – and subsidy – wouldn't take effect until February. You can use our subsidy calculator to get an idea of the size of your subsidy. Then, make sure you enroll by December 15 so that you’re eligible to claim the subsidy for all 12 months of the year.

3. Letting your plan auto-renew? You might be in for a surprise.

If you already have coverage through the Marketplace and are planning to just let it auto-renew for next year, you need to pay close attention to your renewal paperwork. Otherwise, you might find – after it’s too late to make a change for January – that your coverage and premium aren’t what you expected.

Even if you’re 100% happy with the plan you have now, you owe it to yourself to spend at least a little time checking out the available options before December 15. The premium that your insurer charges may be changing for the coming year. (Learn more about premium changes for 2027.) And your subsidy amount is also likely changing, due to changes in the underlying cost of the benchmark plan in your area.

There are also at least 24 states where carriers are exiting the Marketplace at the end of 2026, and at least five states where new carriers will be offering plans for 2027. So your current plan might not be available for renewal, or there might be new plans available in your area.

Your insurer might also be making changes to your benefits, provider network, or covered drug list – or even discontinuing the plan altogether and replacing it with a new one. In short, the plan and price you have on January 1 might be quite different from what you have now.

If you wait until after December 15 (in most states) to comparison shop for your coverage, you’ll get your auto-renewed plan for January and the plan you select for February, potentially missing out on a month of having the plan that will best fit your needs. (Note: If your plan is terminating altogether and not available for renewal, you have until December 31 to pick a replacement plan with a January 1 effective date.)

4. Out-of-pocket expenses won’t transfer in February or March.

What if you’re enrolled in a Marketplace plan and let it auto-renew for the next plan year, and then decide after December 15 that you’d rather have a different plan? Thanks to the extended open enrollment period in nearly every state, you can do that and your new plan will take effect in February.

But it’s important to understand that you’ll be starting over with a new plan in February. This means the out-of-pocket costs counted against your deductible and out-of-pocket maximum will reset to $0, even if you have out-of-pocket expenses in January.

Out-of-pocket expenses reset to $0 on January 1 for all Marketplace plans, so your auto-renewed policy will start over with a new deductible at that point. But if you need medical care in January (and have associated out-of-pocket costs) before your new plan takes effect in February, you’ll potentially have a higher out-of-pocket exposure for the whole year than you would have if you’d picked your new plan by December 15 and had it start January 1.

All of this is a reminder that while most enrollees have until at least mid-January to sign up for new coverage, it’s in your best interest to get your plan selection sorted out by December 15.