It is the first case against him to be prosecuted since a number of sex assault and harassment claims were made at the end of 2017.
The actor lost high-profile roles, including his leading part in House of Cards, and disappeared from public view after the claims surfaced.
Spacey, 59, is alleged to have bought an 18-year-old man several rounds of beer and whiskey at a bar and restaurant he worked at in Nantucket, Massachusetts, in July 2016.
He allegedly said at one point “Let’s get drunk”, according to charging documents.
As they stood next to a piano, it is claimed Spacey put his hands down the man’s trousers.
The actor did not speak at Monday’s hearing in Nantucket.
Dozens of reporters were outside the court as Spacey entered, and at times the award-winning actor raised a small smile.