According to the Department of Defense, the military will begin changing policies that have barred transgender individuals from serving starting in July. Specifically, USA Today reports that each branch of the military will have one year “to implement new policies affecting recruiting, housing, and uniforms for transgender troops.”
The idea was suggested last year by Defense Secretary Ash Carter, who said that unless data could demonstrate negative effects of the policy change, would go forward with allowing transgender people to serve. This, of course, created a heated debate throughout military and governmental organizations.
Ultimately, no compelling data exists. Some policy makers suggested that the costs of the military providing tools and healthcare for troops that are transitioning would negatively impact spending budgets. Critics of the policy change also argued that "Secretary Carter has put the political agenda of a departing administration ahead of the military’s readiness crisis."
Refinery29 notes that it is totally unclear how many transgender troops actually exist: "[A] study by the RAND Corporation estimated that 2,450 of the 1.2 million active-duty members of the military are transgender while a study by UCLA estimated there could be as many as 15,000."