The White House announced Friday that the Trump administration would implement its ban on all transgender service in the military "except under certain limited circumstances." It would also stop all use of Defense Department or Homeland Security resources to fund new sex reassignment surgeries, except to protect the health of individuals who have already begun treatment to reassign his or her sex. The announcement was expected, since it was part of President Trump's executive memo in August 2017 renewing a former transgender military service

According to the White House memo, "transgender persons with a history or diagnosis of gender dysphoria -- individuals who the policies state may require substantial medical treatment, including medications and surgery -- are disqualified from military service except under certain limited circumstances."

The memo further states "the Secretary of Defense, and the Secretary of Homeland Security, with respect to the U.S. Coast Guard, may exercise their authority to implement any appropriate policies concerning military service by transgender individuals."

In July 2017, Mr. Trump had relayed his sudden decision to ban transgender military service in a series of tweets: "After consultation with my Generals and military experts, please be advised that the United States Government will not accept or allow......Transgender individuals to serve in any capacity in the U.S. Military. Our military must be focused on decisive and overwhelming.........victory and cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail."

He had caught Pentagon leadership off guard with the tweets, but the policy has been blocked by several legal challenges, so as those lawsuits progress through the courts, the Pentagon began allowing transgender recruits to seek enlistment on Jan. 1. The president gave Defense Secretary James Mattis six months to develop proposals for transgender individuals currently serving, and Mattis submitted his recommendations last month, but those recommendations have not been revealed. 

A federal judge in Seattle said Mr. Trump has failed to provide evidence related to his claim that he made the decision after "consultation with my generals and military experts."

In June 2016, the Obama administration lifted the longstanding ban on transgender individuals in the military, allowing them to serve openly for the first time. Former Defense Secretary Ash Carter had given the armed services until July 1, 2017 to come up with plans to allow transgender people to join the military, and Defense Secretary James Mattis extended that period until the end of 2017. 

It's not known how many transgender troops are serving -- estimates vary widely. An oft-cited Rand Corp. study said roughly 2,500 transgender personnel may be serving in active duty, and 1,500 in the reserves. It estimated only 30 to 130 active-duty troops out of a force of 1.3 million would seek transition-related health care each year. Costs could be $2.4 million to $8.4 million, it estimated.