Secretary of Defense Ash Carter announced Thursday that the ban on transgender troops openly serving in the U.S. military has been lifted. Carter said the decision is effective immediately, and that training implementation will begin in October. Under the Pentagon’s previous policy, Carter had to personally approve the removal of any transgender service members, which he never did. Within the Marine Corps leadership, there has been some resistance to the idea of lifting the ban, which Carter first proposed last July. “The reality is that we have transgender service members serving in the military today,” Carter said Thursday. He said the department estimates about 2,500 people are transgender out of 1.3 million active-duty service members, and about 1,500 transgender reserve members. “We’re talking about talented and trained Americans who are serving their country with honor and distinction,” he added.