The Hills' Stephanie Pratt pleaded not guilty to a misdemeanor DUI Friday and plans to enter a 30-day residential rehab facility, People reports.
Pratt, 23, was arrested in Hollywood the morning of Oct. 18 for suspicion of a DUI. She was released the next morning on $5,000 bail.
Watch full episodes of The Hills
She faces up to six months behind bars and a $1,000 fine.