The actor told TVLine that his character Kurt will be "back full-force" in the musical drama's fourth season, despite being rejected from performing school NYADA.
"We'll see if he still wants to be a performer," said Colfer. "I don't know if he's hardened after that experience."
However, the star was reluctant to discuss the fate of Kurt and boyfriend Blaine (Darren Criss) in future episodes.
"I almost can't say anything without giving [something] away," he explained. "They're still together as far as I know. So we'll see where that takes them."
Glee co-creator Ryan Murphy recently confirmed that part of the show's new season will be shot on location in New York.
"Nothing is in stone, because we're still budgeting, but I would love to come once every five weeks and shoot a lot of scenes there," he said. "We are 100 percent doing that - we're not going to do it all on a sound stage."
Glee will return to Fox on Thursday, September 13. The series airs on Sky1 in the UK.