Taylor Murphy, 17, has been missing from Wilkinsburg since Sept. 20.
Authorities believe she could still be in the Pittsburgh area. She is classified by the National Center for Missing and Exploited Children as an endangered runaway.
Taylor is described as 5 feet, 4 inches tall; 140 pounds; with black hair and brown eyes; and having a tattoo on her upper arm. She will turn 18 on Jan. 23.
Anyone having information about Taylor should contact the National Center for Missing & Exploited Children at 1-800-843-5678 (1-800-THE-LOST) or call the Penn Hills Police Department at 412-473-3056.