Attorney General Maura Healey on Thursday joined with 16 of her counterparts from across the country in challenging a Texas ruling that the 2010 Affordable Care Act is unconstitutional, a move Healey said was aimed at protecting families from losing their access to medical care.

"What this ruling would do, if allowed to go forward, would really throw into jeopardy not only millions and millions of Americans' access to health care, but also the effectiveness and the functioning of health care markets generally," Healey told the News Service. "It's a terribly misguided decision, wrong decision, and that's why we're taking it up on appeal."

California Attorney General Xavier Becerra led the group -- which also includes the attorneys general from Connecticut, Delaware, Hawaii, Illinois, Kentucky, Minnesota, New Jersey, New York, North Carolina, Oregon, Rhode Island, Vermont, Virginia, Washington, and the District of Columbia -- in filing a notice that it plans to appeal the Dec. 14 ruling from the U.S. District Court for the Northern District of Texas.

Healey said that while the Texas ruling against former President Barack Obama's signature health care law hasn't changed the status quo of how the system currently operates, she has talked to "so many people that are concerned" about what it could mean for the future.

"They have preexisting conditions, they have young people under 26 affected by this," she said after attending Gov. Charlie Baker's inauguration. "We have so many people potentially affected by this, and the goal here is to make sure that this ruling gets thrown out in the Fifth Circuit and we can go back to ensuring that we have a workable system in place."

The U.S. Department of Health and Human Services, in a Dec. 17 statement, said the District Court ruling in Texas v. Azar is not a final judgement or an injunction that halts enforcement of the law.

"Therefore, HHS will continue administering and enforcing all aspects of the ACA as it had before the court issued its decision," the statement said. "This decision does not require that HHS make any changes to any of the ACA programs it administers or its enforcement of any portion of the ACA at this time."

The attorneys general coalition plans to "continue to defend the law against the ruling," according to Healey's office.

U.S. Sen. Edward Markey last month predicted Massachusetts would "be in the front of the line in appealing" the ruling, potentially taking it to the Supreme Court if necessary. He said then he saw "good reason to believe that this decision will not stand as it goes through the court process."

Healey on Thursday noted her office has been involved in other lawsuits against the Trump administration over the health care law.

"We were there early to defend the ACA," she said. "We're here now to defend the ACA, to stand up for health care for people here in Massachusetts."