it looks like now they're changing it and they'll be allowing Green Card holders according to this news but in the beginning even Green card holders were to be affected by the ban.
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http://www.reuters.com/article/us-usa-trump-immigration-greencard-idUSKBN15C0KX

U.S. green card holders will require additional screening before they can return to the United States, the White House said on Saturday.

Earlier, a Department of Homeland Security official said people holding green cards, making them legal permanent U.S. residents, were included in President Donald Trump's executive action temporarily barring people from seven Muslim-majority countries from entering the United States.

"It will bar green card holders," Gillian Christensen, acting Department of Homeland Security spokeswoman, said in an email.

A senior White House official later sought to clarify the situation, saying green card holders who had left the United States and wanted to return would have to visit a U.S. embassy or consulate to undergo additional screening.

"You will be allowed to re-enter the United States pending a routine rescreening," the official said