Adams Township police Chief William Westerman says four teens from the Mars Home for Youth called for a limo about 6:15 a.m. Wednesday and met it at a nearby high school parking lot.
The limo driver got out when he realized the teens didn't have enough money for the ride. The teens drove off and picked up two more teens soon after.
Police say as many as seven teens may have left the home, about 20 miles north of Pittsburgh.
Officials at the home have issued a statement citing concerns about the home's reputation and the safety of those involved. But a spokeswoman won't say how many teens are missing, citing the police investigation.