BOSTON — Massachusetts Attorney General Maura Healey is leading a group of 15 Democratic attorneys general in opposing President Donald Trump’s administration’s plan to bar transgender individuals from openly serving in the military.

The group filed a brief Monday in U.S. District Court for the District of Columbia arguing that banning transgender individuals from the military is unconstitutional and against the interest of national defense and that it harms the transgender community.

“Our military should be open to every brave American who volunteers to serve,” Healey said.

In the brief, the attorneys general argue that “nothing about being transgender inhibits a person’s ability to serve in the military or otherwise contribute to society.”

The brief also argues that Trump made an “irrational decision to reverse recent progress and reinstitute formal discrimination against transgender individuals” and that the administration’s “purported justifications for reinstating the ban are contradicted by research, reason, and experience.”

The attorneys general said they filed the brief in part because the ban harms transgender individuals in their states.

The brief supports a lawsuit filed in August by The National Center for Lesbian Rights and GLBTQ Legal Advocates & Defenders on behalf of eight transgender individuals, including members of the Air Force, Coast Guard and the Army, as well as students at the U.S. Naval Academy and in the ROTC program at the University of New Haven.

The Justice Department earlier this month asked the court to dismiss the lawsuit. A spokeswoman said at the time that the lawsuit is premature and that the Defense Department is reviewing service requirements.

The lawsuit was filed after Trump tweeted in July that the federal government “will not accept or allow” transgender individuals to serve “in any capacity” in the military. That would reverse a 2016 policy change allowing transgender people to serve openly.

Trump later directed the Pentagon to extend indefinitely a ban on transgender individuals joining the military, and he gave Defense Secretary Jim Mattis six months to come up with a policy on how to deal with those currently serving.

Trump also directed Mattis to halt the use of federal funds to pay for sexual reassignment surgeries and medications, except in cases where it is deemed necessary to protect the health of an individual who has already begun the transition.

Besides Healey, the attorneys general who signed onto the court brief represent California, Connecticut, Delaware, Hawaii, Illinois, Iowa, Maryland, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Washington, D.C., and Vermont.

BOSTON — Massachusetts Attorney General Maura Healey is leading a group of 15 Democratic attorneys general in opposing President Donald Trump’s administration’s plan to bar transgender individuals from openly serving in the military.

The group filed a brief Monday in U.S. District Court for the District of Columbia arguing that banning transgender individuals from the military is unconstitutional and against the interest of national defense and that it harms the transgender community.

“Our military should be open to every brave American who volunteers to serve,” Healey said.

In the brief, the attorneys general argue that “nothing about being transgender inhibits a person’s ability to serve in the military or otherwise contribute to society.”

The brief also argues that Trump made an “irrational decision to reverse recent progress and reinstitute formal discrimination against transgender individuals” and that the administration’s “purported justifications for reinstating the ban are contradicted by research, reason, and experience.”

The attorneys general said they filed the brief in part because the ban harms transgender individuals in their states.

The brief supports a lawsuit filed in August by The National Center for Lesbian Rights and GLBTQ Legal Advocates & Defenders on behalf of eight transgender individuals, including members of the Air Force, Coast Guard and the Army, as well as students at the U.S. Naval Academy and in the ROTC program at the University of New Haven.

The Justice Department earlier this month asked the court to dismiss the lawsuit. A spokeswoman said at the time that the lawsuit is premature and that the Defense Department is reviewing service requirements.

The lawsuit was filed after Trump tweeted in July that the federal government “will not accept or allow” transgender individuals to serve “in any capacity” in the military. That would reverse a 2016 policy change allowing transgender people to serve openly.

Trump later directed the Pentagon to extend indefinitely a ban on transgender individuals joining the military, and he gave Defense Secretary Jim Mattis six months to come up with a policy on how to deal with those currently serving.

Trump also directed Mattis to halt the use of federal funds to pay for sexual reassignment surgeries and medications, except in cases where it is deemed necessary to protect the health of an individual who has already begun the transition.

Besides Healey, the attorneys general who signed onto the court brief represent California, Connecticut, Delaware, Hawaii, Illinois, Iowa, Maryland, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Washington, D.C., and Vermont.