The U.S. Department of Education Office for Civil Rights announced Monday it is investigating Jeffco Public Schools over the district’s policy on sleeping arrangements for transgender students on overnight school trips.

Jeffco’s policy says that in most cases, transgender students “should be assigned to share overnight accommodations with other students that share the student’s gender identity.”

It also says the needs of transgender students will be assessed on a case-by-case basis to maximize their social integration, ensure their safety and comfort, and minimize stigmatization.

The Education Department is launching an investigation under Title IX, which prohibits discrimination on the basis of gender. Under its contested interpretation of the law, the Trump administration has used Title IX to challenge transgender rights policies.

The Jeffco district “allegedly misleads parents by informing them that girls and boys will be separated for overnight accommodations without divulging that its definition of ‘girl’ includes boys who claim a female identity,” the department said.

Jeffco Public Schools said in a statement that its policy is grounded in Colorado’s anti-discrimination law, the regulations for which say transgender individuals should be allowed to use restrooms, locker rooms and dormitories that are consistent with their gender identity.

“Families always have the ultimate choice whether their student participates in any unique programming that involves overnight accommodations,” Jeffco Public Schools said in its statement. “We are unwavering in our commitment to the well-being of our students, staff and families, and we strictly adhere to all Colorado state laws governing their treatment.”

Title IX does not prohibit “the degree of protection that the state of Colorado provides,” the district said.

This is the second Title IX investigation of a large Colorado school district since Trump took office in January. That same month, the U.S. Department of Education announced it was investigating Denver Public Schools for converting a girls’ restroom into an all-gender restroom.

Jeffco’s policy on overnight accommodations for transgender students is also the subject of an ongoing federal lawsuit filed by several district families. One family claimed their daughter, then 11 years old, was assigned to share a bed with a transgender student on an out-of-state overnight trip. The U.S. Department of Education’s news release cited the family’s claim.

In court documents, Jeffco Public Schools argued that the district “does not typically know the sex assigned at birth of any of its students” because parents can legally change the sex designation on their child’s birth certificate before enrolling the child in school.

Jeffco also argued that it honors students’ requests “to room by themselves, with specific classmates or with their parents,” and did so in the case of the 11-year-old. When she expressed discomfort at rooming with a transgender student, the trip organizers “quickly and discreetly” moved her to a different room, the district wrote in a court document.

Chalkbeat Colorado is a nonprofit news organization covering education issues.