A federal judge in North Dakota has ruled in favor of 19 states that challenged a Biden administration rule allowing — for the first time — enrollment in Affordable Care Act coverage by people brought to the U.S. as children without immigration paperwork, known as “Dreamers.”

The move effectively bars those who have qualified for the Deferred Action for Childhood Arrivals program in those 19 states from enrolling in or getting subsidies for ACA plans. It does not appear to affect enrollment or coverage in other states, lawyers following the case said Tuesday.

The Biden administration is likely to appeal, although a Centers for Medicare & Medicaid Services representative said in an email that the agency would not comment on the litigation.

While an appeal may be filed quickly, a final decision may not occur before the incoming Trump administration takes office. “They could take a different position on the litigation,” said Zachary Baron, a legal expert at Georgetown Law, who helps manage the O’Neill Institute Health Care Litigation Tracker.

In the meantime, it is not clear what will happen to Dreamer enrollees in the 19 states whose coverage has already started or begins early next year, although the judge’s ruling does not say it is retroactive, Baron noted.

The case was filed in August in U.S. District Court for the District of North Dakota.

Previously, the federal government estimated that about 100,000 uninsured people out of the half-million DACA recipients might sign up starting Nov. 1, the sign-up season start date in all states except Idaho.

The Biden administration rule, finalized in May, clarified that those who qualify for DACA would be considered “lawfully present” for the purposes of enrolling in plans under the ACA, which are open to American citizens and what are called “lawfully present” immigrants.

In granting a preliminary injunction and stay, U.S District Judge Daniel Traynor, who was appointed in 2019 by then-President Donald Trump, noted in his Monday ruling that the plaintiffs were likely to win on the merits of their argument.

States challenging the ACA rule say it will cause administrative and resource burdens as more people enroll, and that it will encourage additional people to remain in the U.S. when they don’t have permanent legal authorization. In addition to Kansas and North Dakota, the states that joined the lawsuit are Alabama, Arkansas, Florida, Idaho, Indiana, Iowa, Kentucky, Missouri, Montana, Nebraska, New Hampshire, Ohio, South Carolina, South Dakota, Tennessee, Texas, and Virginia.

“Judge Traynor’s ruling is both disappointing and wrong on the law,” said Nicholas Espíritu, a deputy legal director of the National Immigration Law Center, in an emailed statement. “While we study the court’s ruling to evaluate the next steps in this case, we will continue to fight on behalf of our clients and hundreds of thousands of DACA recipients who have been waiting over a decade to access life-sustaining care under the Affordable Care Act.”

DACA was established through executive action in June 2012 by President Barack Obama, protecting from deportation and providing work authorization to some unauthorized residents brought to the U.S. as children by their families. It had certain requirements, including that they arrived before June 2007 and had completed high school, were attending school, or were serving in the military.

Before the injunction, 19 other states and the District of Columbia filed a brief in support of the Biden administration rule. Led by New Jersey, those states include many in the East and West, including California, Colorado, Nevada, New Mexico, New York, Oregon, and Washington.