President Trump Just Banned Transgender People From the U.S. Military. Here’s What to Know

President Donald Trump tweeted Wednesday morning that transgender individuals will not be able to serve in the military “in any capacity,” reversing a policy under former President Barack Obama that allowed transgender people to serve openly.

“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,” the President said in a series of tweets. “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. Thank you.”

Here’s what to know about the President’s announcement banning transgender people from the military.

Why did Trump ban transgender people from serving in the military?

Trump said on Twitter that allowing transgender people to serve in the military would bring “tremendous medical costs and disruption.” A 2016 RAND Corporation study, which was commissioned by the Defense Department, found that expanding medical coverage to transgender members would cost between $2.4 million to $8.4 million, with an average median cost increase of $5.4 million annually. That median cost would amount to a health-care spending increase of $0.22 per service member per month, according to RAND.

But that’s only a small drop in the bucket when it comes to total military health care costs. In total, active-component health-care spending amounts to $6 billion annually, and the Department of Defense spends $49.3 billion each year on health care, the RAND report said.

What happens to transgender people who already serve in the military?

The White House did not immediately respond to a request for comment on how it will address transgender servicemembers that already openly serving in the military.

“We will continue to work closely with the White House to address the new guidance provided by the Commander-in-Chief on transgender individuals serving in the military,” Pentagon spokesperson Capt. Jeff Davis said in a statement, according to ABC News. “We will provide revised guidance to the Department in the near future.”

How many transgender people serve in the military?

RAND’s 2016 analysis estimated that between 1,320 and 6,630 people serve in the military on active duty and another 830 to 4,160 serve in reserves duty. This makes up 0.1-0.5% of both active duty and selected reserve service members. In total, there are about 1.2 million in active military service and another 800,000 in reserves, according to the Department of Defense.

How does this differ from President Obama’s policy?

Former Secretary of Defense Ashton Carter, who was nominated by Obama, announced in July 2016 that the military would end its ban on open service of transgender troops. The ban was formerly lifted on July 1, 2016. At the time, the five branches of the military were given a year to create new transgender-inclusive guidelines.

Obama’s White House voiced its support at the time, issuing a statement saying: “The President agrees with the sentiment that all Americans who are qualified to serve should be able to serve. We here at the White House welcome the comments from the Secretary of Defense.”

How are people reacting?

LGBTQ activists have come out against Trump’s ban. GLAAD, an organization dedicated to promoting acceptance for the LGBTQ community, said the announcement was a “direct attack on transgender Americans.” Chelsea Manning called the move “cowardice” in a tweet on Tuesday.

Many politicians, including New York Gov. Andrew Cuomo, Florida Congresswoman Ileana Ros-Lehtinen and Massachusetts Sen. Ed Markey, voiced their opposition on Twitter as well.