ACA Open Enrollment Guide

To be able to enroll on the ACA’s Marketplace:⁴

• You must live in the United States.
• You must be a U.S. citizen or national or be lawfully present, and DACA recipients are no longer allowed to use the Marketplace. (Washington state allows undocumented immigrants to use its Marketplace, although there may be changes to that approach as of 2027.⁵ and Colorado has a separate platform that undocumented immigrants can use to enroll in coverage.)
• You must not be incarcerated.
• You cannot be enrolled in Medicare coverage.

Being eligible to enroll in the Marketplace is not the same as being eligible for financial assistance. In short, the income-based subsidies available through the Marketplace/exchange are reserved for people who aren’t eligible for Medicaid, zero-premium Medicare Part A, or coverage offered by an employer that’s deemed affordable and comprehensive. (Here’s how to determine whether employer-sponsored coverage is affordable to you.)

You can use our subsidy calculator to get an idea of whether you’re eligible for premium subsidies, and if so, how much those subsidies could be.

Note: As of 2027, some immigrants will no longer be eligible for subsidies, including refugees, asylees, people with temporary protected status (TPS), and people with work or student visas. To be subsidy-eligible, non-citizens will need to be either lawful permanent residents (LPRs), Cuban or Haitian entrants, or COFA migrants.⁶

Premium subsidies are a refundable tax credit.⁷ You may qualify for a subsidy based on your projected household income for the year you’ll have coverage. And then you’ll need to reconcile that with the IRS when you file your tax return for that year, based on your actual income.

Premium subsidy rules are designed to ensure that subsidy-eligible individuals won’t pay more than a certain percentage of their household income in premiums for the benchmark (second-lowest-cost Silver) plan in the Marketplace.⁸

The percentage of household income that people are expected to pay depends on their income. These percentages were reduced from 2021 through 2025, and there was no upper income limit for subsidy eligibility during those years. These temporary subsidy enhancements were due to the American Rescue Plan and the Inflation Reduction Act.

But those provisions were temporary, and expired at the end of 2025. For 2027, the percentage of income that people have to pay for the benchmark plan ranges from 2.15% to 10.22% of household income.⁹ And anyone with household income above 400% of the federal poverty level no longer qualifies for any subsidies at all – regardless of what percentage of their income they have to pay for their health insurance.

Cost-sharing reductions: The other ACA subsidy

Marketplace cost-sharing reductions (CSR)¹⁰ are another type of Obamacare subsidy. CSR assistance is designed to ensure that people with low to moderate incomes can afford to receive health care services. Enrollees who qualify for CSR usually also qualify for premium subsidies.

CSR subsidies result in lower out-of-pocket costs, including lower deductibles and copays. For applicants with eligible incomes, these subsidies are automatically incorporated into all of the available Silver-level plans. But if you’re eligible for CSR subsidies and you buy a non-Silver plan, you’ll forfeit this advantage

In addition to federal premium subsidies and CSR subsidies, some state-run Marketplaces offer their own subsidies.

No. It is unlawful for someone to sell you a Marketplace plan (or an individual/family plan outside the exchange) if you already have Medicare, even if you only have either Medicare Part A or Part B.¹¹ So if you’re enrolled in Medicare, the Marketplace open enrollment period does not apply to you.

There is no longer a penalty imposed by the federal government for being uninsured. But some states impose penalties when residents do not have health coverage or a qualifying exemption. They include:

• Massachusetts¹²
• New Jersey¹³
• California¹⁴
• Rhode Island¹⁵
• District Of Columbia¹⁶

Auto-renewal or automatic re-enrollment (when a plan is terminating) for the coming year’s coverage is available through the Marketplaces in every state. (This will likely end after the 2027 plan year, due to the “Big Beautiful Bill” that was enacted in 2025.)¹⁷

However, it is generally not in your best interest to rely on automatic renewal. Selecting your own plan for the coming year is better than relying on auto-renewal or a Marketplace algorithm that will select a new plan on your behalf.

And there were some changes to the auto-renewal protocols for 2026 coverage, as a result of a federal rule that was finalized in 2025. Marketplace cost-sharing reductions (CSR) are only available on Silver plans. So HealthCare.gov implemented a new protocol in 2024 that would automatically move a Bronze enrollee to a Silver plan if the person was eligible for CSR and the Silver plan had the same or lower premium and the same provider network. That protocol was no longer available for the 2026 plan year, so the person in that scenario was auto-renewed into their same Bronze plan, despite the fact that they’re missing out on CSR benefits. That will continue to be the case for 2027 coverage.

As open enrollment approaches, you’ll want to pay close attention to any notices you receive from your health plan and Marketplace, as they will let you know how your benefit details, monthly premium, and premium subsidy (if applicable) are changing for the coming year. You’ll also want to carefully compare the other options available in your area, as they may not be the same as the options that were available for this year.

You may find that keeping your current plan is still the best option. But it’s better to actively make that decision than let it be the default.

You can certainly choose to select a plan and complete the enrollment process on your own, through the Marketplace/exchange website (or via an enhanced direct enrollment entity if you’re in a state that uses HealthCare.gov).¹⁸

But if you prefer to have help with the process, it’s available for free online, over the phone, and from people in your community:

Health insurance Navigators

• Provide education and outreach about the Marketplace and available health plans, help applicants determine whether they qualify for subsidies or Medicaid, and assist in the enrollment process.
• Can generally provide assistance after you enroll, helping with issues like eligibility appeals and how to utilize your health coverage.
• Are funded by the Marketplace. The funding comes from the federal government in states that utilize a federally run exchange, and by the state in states that run their own exchanges. However, the Trump administration has drastically reduced Navigator funding for the states that use HealthCare.gov, so there aren’t as many Navigators available as there were during the Biden administration.¹⁹

Certified application counselors (CACs)

• Similar to Navigators, but their focus tends to be strictly on helping people enroll, without the more extensive assistance that some Navigators can provide.
• The exchange designates local “CAC designated organizations” (health centers, faith-based organizations, colleges, etc.) and people who are affiliated with or employed by those organizations are eligible to serve as CACs.²⁰
• CAC funding can come from a variety of state and federal sources, and CACs are often volunteering their time to help people enroll in health coverage. The Marketplace does not provide funding for CAC organization.
• Learn more about certified application counselors.

Insurance brokers and agents

• Licensed by the state and certified by the Marketplace/exchange.
• Can help consumers determine subsidy or Medicaid eligibility, and they can also make plan recommendations based on a client’s particular situation.²¹ (Navigators and CACs cannot do this).
• Provide ongoing assistance for questions and problems regarding billing, utilization, claims, and appeals.
• Generally are required to carry errors and omissions insurance.