Standby Michael Lee Brown will take center stage as Evan for the Sunday, September 3 matinee, as well as Wednesday and Saturday matinee performances through November 11. Platt is currently scheduled to play all shows during his final week.
As previously announced, The Real O'Neals star Noah Galvin will assume the role beginning November 21. Taylor Tresnch, who currently plays Barnaby Tucker in the Broadway revival of Hello, Dolly! takes over in mid-January.
Brown—as well as Colton Ryan—understudy a trio of roles in the Tony-winning musical: the title character, Connor Murphy, and Jared Kleinman.
The current cast at the Music Box Theatre also includes Rachel Bay Jones, who won a Tony for her performance as Evan's mother Heidi, Tony nominee Mike Faist, Jennifer Laura Thompson, Laura Dreyfuss, Kristolyn Lloyd, Michael Park, and Will Roland.
In addition to wins for Best Musical and Platt and Jones' performances, Dear Evan Hansen earned Tony Awards earlier this year for book writer Steven Levenson, composers Benj Pasek and Justin Paul, and orchestrator Alex Lacamoire.