The news comes after Buzzfeed reported an allegation by "Star Trek: Discovery” star Anthony Rapp that Spacey climbed on top of him in bed in 1986 when he was 14 years old and Spacey was in his 20s.
A spokesperson for Spacey made the announcement in a statement released on Thursday, but did not provide any further details.
"Kevin Spacey is taking the time necessary to seek evaluation and treatment. No other information is available at this time,” the statement said.
Spacey sparked a social media firestorm on Sunday after he posted a lengthy statement on Twitter addressing Rapp's allegations, claiming he did not remember the episode.
"I have a lot of respect and admiration for Anthony Rapp as an actor. I'm beyond horrified to hear this story," Spacey said Sunday. "I honestly do not remember the encounter ... But if I did behave then as he describes, I owe him the sincerest apology for what would have been deeply inappropriate drunken behavior."
In the same statement, Spacey said that the situation had "encouraged" him to come out as a gay man.
"Anthony Rapp's story is deeply troubling," he began. "During the time I worked with Kevin Spacey on 'House of Cards' I neither witnessed nor was aware of any inappropriate behavior on set or off. That said, I take reports of such behavior seriously, and this is no exception. I feel for Mr. Rapp and I support his courage."
On Tuesday, Netflix announced that it would suspend production of the show’s final season in wake of the accusations.
"Media Rights Capital and Netflix have decided to suspend production on 'House of Cards' season six, until further notice, to give us time to review the current situation and to address any concerns of our cast and crew," Netflix said.
A Netflix representative confirmed to ABC News that the decision to end the show after its sixth season was made before the scandal broke.
The International Academy of Television Arts & Sciences also spoke out against Spacey Monday, and canceled its plans to award the actor with the 2017 International Emmy Founders Award. The honor is meant to recognize individuals who cross cultural boundaries.