The 30-year-old actor "has voluntarily admitted himself to a treatment facility for substance addiction," his representative told People.com Monday. "He graciously asks for your respect and privacy as he takes the necessary steps towards recovery."
No other details regarding what led to the decision to seek treatment were immediately available.
Montieth has long battled drug and alcohol addiction and spent time in rehab 11 years ago, People.com said.
Notable deaths of 2014 [PHOTOS]