Courtney Baltimore, 16, has been missing from her home in Pittsburgh since Oct. 23.
According to the National Center for Missing and Exploited Children, she might have traveled to Hazelwood or Philadelphia.
She is described as 6 feet tall and weighing 180 pounds, with black hair and brown eyes. She has a heart tattooed on her right hand.
Anyone with information should contact the Pittsburgh Police Department at 412-255-2937 or the National Center for Missing and Exploited Children at 1-800-THE-LOST (843-5678).