The College Board announced on Thursday that Florida school districts should no longer offer Advanced Placement Psychology, one of the most popular A.P. courses, the latest skirmish in its battle with the state’s Department of Education over how to teach race, gender and sexual orientation.

The College Board, the nonprofit that oversees advanced placement courses and the SAT, revoked its support for A.P. psychology in Florida, saying it would not abide by the state’s demand to remove a longstanding section on gender and sexual orientation.

“The Florida Department of Education has effectively banned A.P. Psychology in the state,” the College Board said in a statement.

The Department of Education fired back, accusing the College Board of “playing games with Florida students” one week before school starts.

“The Department didn’t ‘ban’ the course,” the department said in a statement. “The course remains listed in Florida’s Course Code Directory for the 2023-24 school year. We encourage the College Board to stop playing games with Florida students and continue to offer the course and allow teachers to operate accordingly.”

Under an expanded Florida rule, instruction on gender identity and sexual orientation is now restricted in most cases through the 12th grade. The Florida Department of Education had asked the College Board and other providers of advanced, college-level courses to search their offerings for potential violations.

But the College Board said that it would not modify its content, and that any course that did not address gender and sexual orientation should not be labeled “advanced placement.”

“To be clear, any A.P. Psychology course taught in Florida will violate either Florida law or college requirements,” the College Board said.

The College Board, a powerful nonprofit, has been waging war with the administration of Gov. Ron DeSantis, a Republican, since earlier this year when his administration rejected the College Board’s new African American studies course. The curriculum included topics such as “queer studies,” reparations and the Black Lives Matter movement, and the administration objected, citing a state law limiting how racism and other aspects of history are taught in public schools.

The battle exposed the College Board’s negotiations with the DeSantis administration, and its changes to the curriculum.

But the fight over A.P. psychology moves the battlefield from a new course that was taking feedback and being piloted, to long-established academic territory.

A.P. Psychology has been around for three decades, and it has included a section on gender and sexual orientation as part of the framework since the course’s inception, the College Board said. The section comes as part of a unit on developmental psychology, spanning childhood and adolescence to older adulthood, with themes on “moral development” as well as on gender and sexual orientation.

“Describe how sex and gender influence socialization and other aspects of development,” the College Board’s framework for that segment says.

The American Psychological Association​ has supported the inclusion of gender identity and sexual orientation as a necessary part of studying human development.

“An advanced placement course that ignores the decades of science studying sexual orientation and gender identity would deprive students of knowledge they will need to succeed in their studies, in high school and beyond,” the group’s chief executive, Arthur C. Evans Jr., said in a statement Thursday.

In refusing to modify its course, the College Board said in June that it had “learned from our mistakes” in the rollout of the A.P. African American Studies course and asserted that “we must be clear from the outset where we stand.”

The latest developments leave school districts scrambling just days before the school year is scheduled to start next week for some districts. ​

More than 28,000 students in Florida took the A.P. psychology course last year, and the class can result in college credit for some students who score high enough on an end-of-course exam.