Epstein, who visited in the spring, decided it was time to commit to the Illini.
"I just thought it was time," Epstein said. "Before the season and it happened to be my birthday."
Epstein talked about what really sold him on the program. He also said 2016 teammate Dominic Thieman was "very excited" for him.
"It's Big 10 football," Epstein said. "I have a great relationship with the coaches."