A shorter open enrollment period, less help choosing a plan, higher health insurance premiums for many people — those are just a few changes now brewing that could affect your health insurance for 2026 if you have coverage through the Affordable Care Act marketplace. One shift is the scheduled end of more generous financial subsidies that, in recent years, have allowed many more people to qualify for marketplace plans with lower or no monthly premiums.

What’s more, the Trump administration, through the Centers for Medicare and Medicaid Services, proposed a new rule on March 10 involving about a dozen changes affecting enrollment and eligibility in the marketplaces. The agency, which oversees the marketplaces, said the rule was intended to improve affordability while “maintaining fiscal responsibility.”

Some health insurance experts, however, say the changes could make it more challenging for people to enroll in or renew coverage. If it becomes final, the rule will “restrict marketplace eligibility, enrollment and affordability,” according to an analysis in the journal Health Affairs that was co-written by Katie Keith, director of the Health Policy and the Law initiative at Georgetown University Law Center.

The public still has a few weeks to comment on the proposal. The administration is likely to move quickly to write a final version because insurers are now developing rates for health plans for 2026, Ms. Keith said.

Here are some of the possible changes to look out for.

Why is extra financial help for premiums set to end?

Enhanced premium help, first offered in 2021 as part of the federal government’s pandemic relief program, was extended through 2025 by the Inflation Reduction Act. The more generous subsidies increased aid to low-income people who already qualified for financial help under the Affordable Care Act, and added aid for those with higher incomes (more than $60,240 for individual coverage in 2025 coverage) who didn’t previously qualify.

The extra subsidies, given in the form of tax credits, helped marketplace enrollment balloon to some 24 million people this year, from about 12 million in 2021. The average enhanced subsidy, which varies by a person’s income, is about $700 per year, said Cynthia Cox, a health care expert at KFF, a nonprofit research group.

Unless Congress renews them, however, the extra subsidies will expire at the end of this year. Almost all marketplace enrollees would see “steep” premium increases in 2026, according to a KFF analysis. And about 2.2 million people could become uninsured next year because of higher premiums, the Congressional Budget Office estimates.

While the extra help has expanded coverage, it comes at a price. If made permanent, the more generous subsidies would cost $335 billion over the next 10 years, according to budget office projections.

With Republicans in control of Congress, it’s unclear if Democrats can broker a deal to continue the Biden-era enhanced subsidies.

How would open enrollment change for Obamacare plans?

The Trump administration’s proposed rule would shorten, by roughly four weeks, the annual window when people select coverage for the coming year. Open enrollment would start on Nov. 1 and end on Dec. 15 for all marketplace exchanges. Currently, the federal end date is Jan. 15, and some state exchanges keep enrollment open as late as Jan. 31.

In a fact sheet about the rule, the administration said the reasons for the change included reducing “consumer confusion” and aligning the window more closely with enrollment dates for many job-based health plans.

However, consumer advocates say that if the goal is to encourage enrollment, a January deadline makes sense. People are often busy during the year-end holiday season, so the extra weeks give people more time to consider their coverage, said Cheryl Fish-Parcham, director of private coverage at Families USA, a health insurance advocacy group.

Louise Norris, a health policy analyst at Healthinsurance.org, a consumer information and referral website, said a mid-December deadline could put some people in a bind.

Most people covered by marketplace plans are automatically re-enrolled for the coming year, but some may not realize that their premium has changed until they get a bill in January. Under the current January open enrollment deadline, if they can no longer afford their plan, they can still switch to less expensive coverage starting in February. “You have a ‘do over,’” Ms. Norris said. But if the enrollment deadline moves to December, they could be faced with a more costly plan, or dropping coverage.

Would special enrollment windows be affected?

Most people can’t sign up for Obamacare coverage outside open enrollment unless they have a big life event, like losing a job, getting married or having a baby, that qualifies them for a special enrollment window. But in 2022, an exception was created to allow low-income people (annual income of up to $22,590 for individual coverage in 2025) to enroll year-round.

The Trump administration’s proposed rule would abolish this option, which has been available in most states. The agency says it is ending the special enrollment period for low-income people because of concern that it contributes to “unauthorized” enrollments, including when rogue brokers enroll people in plans without their knowledge. The exception may end sometime this year, before open enrollment begins, health experts said.

People who have delayed seeking coverage should consider checking their eligibility now, Ms. Norris said. “That opportunity might go away well before open enrollment,” she said.

In recent years, Ms. Norris said, Healthcare.gov has verified eligibility for special enrollment periods only if the stated reason was a loss of other coverage, the most common reason. But the new rule, citing an apparent increase in “misuse and abuse” of special enrollment periods, would reinstate verification for all reasons.

“We know the more hoops people have to jump through, the less likely they are to enroll,” Ms. Norris said.

Will ‘dreamers’ still be eligible for coverage?

No. The administration’s proposed rule would exclude DACA recipients, known as “dreamers,” from Affordable Care Act health plans. (DACA stands for Deferred Action for Childhood Arrivals, a program adopted in 2012 that applies to certain undocumented immigrants brought to the country as children.) DACA recipients are protected from deportation and can work legally. They were given access to marketplace insurance plans in late 2024 under the Biden administration and remain eligible in all but 19 states, where an injunction prohibits their enrollment, according to the National Immigration Law Center. (The legal status of the dreamers generally remains uncertain because of an ongoing court challenge.)

Where can I share my opinion about the proposed rule?

Public comments can be submitted online or by mail until April 11. Details are available on the Federal Register website.

Will I be able to get help choosing a marketplace plan?

The Centers for Medicare and Medicaid Services in February cut funding for “navigators,” helpers who guide people through selecting a health plan, to $10 million this year, from almost $100 million under the Biden administration. Navigator groups also conduct outreach and education, and help people who aren’t eligible for marketplace plans enroll in Medicaid, according to KFF. The Trump administration argues that the navigator program isn’t cost effective.