The Pentagon has directed military branches to identify service members diagnosed with gender dysphoria by March 26, with removal procedures set to begin within 30 days after that deadline.

A memo sent to Department of Defense officials on Thursday outlined the directive, which comes as part of the Pentagon’s response to a lawsuit, according to the Associated Press. A senior defense official, speaking anonymously, estimated that approximately 4,200 active-duty and reserve troops have been diagnosed with gender dysphoria.

This follows an executive order signed by President Donald Trump to ban transgender individuals from serving in the military, a policy currently being challenged in court.

According to the senior defense official, the military has spent around $52 million between 2015 and 2024 on psychotherapy, hormone treatments, sex change surgeries, and other medical procedures for transgender service members.

Darin Selnick, defense undersecretary for personnel, stated in the memo, “The medical, surgical, and mental health constraints on individuals who have a current diagnosis or history of, or exhibit symptoms consistent with, gender dysphoria are incompatible with the high mental and physical standards necessary for military service.”

The memo further asserts that the integrity and effectiveness of the U.S. military “is inconsistent” with the medical needs of transgender individuals undergoing gender transitions and states that gender is “immutable, unchanging during a person’s life.”

Initial data from military officials suggests that about 600 transgender troops can be quickly identified in the Navy, between 300 and 500 in the Army, and fewer than 50 in the Marine Corps. These numbers are expected to rise as more service members are identified through documented medical treatments. Officials noted that troops who transitioned before enlisting may not yet be accounted for, Fox reports.

The policy allows for two exceptions. According to the Associated Press, these exceptions apply “if transgender personnel who seek to enlist can prove on a case-by-case basis that they directly support warfighting activities, or if an existing service member, who was diagnosed with gender dysphoria, can prove they support a specific warfighting need and never transitioned to the gender they identify with and proves over 36 months they are stable in their biological sex ‘without clinically significant distress.’”