He will appear in court on 7 January over the incident, which allegedly occurred in Nantucket in July 2016.
On Monday, Mr Spacey posted a video in which he appears to deny any wrongdoing while in character as Frank Underwood from House of Cards.
"I'm certainly not going to pay the price for the things I didn't do," he says in the clip.
"You wouldn't believe the worst without evidence, would you?" he asks. "You wouldn't rush to judgements without facts."
The alleged victim is the son of former television news presenter Heather Unruh, who spoke publicly about the incident last year.
She accused Mr Spacey of buying her then 18-year-old son alcohol - the drinking age in Massachusetts is 21 - and then groping him.
In the video, Mr Spacey speaks in Frank Underwood's accent and addresses the viewer directly, much like he did throughout his five seasons on House of Cards.
"Of course some believed everything," he says. "They're just waiting with bated breath to hear me confess it all."
"They're going to say I'm being disrespectful, not playing by the rules," he adds. "Like I ever played by anyone's rules before. I never did. And you loved it."
Frank Underwood was the power-hungry and conniving protagonist of the Netflix series, and murdered a journalist and a politician before he was killed off ahead of season six.