It has been over a year since Warren County outsourced its ambulance service billing and county commissioners will learn Sept. 11 at 6:30 p.m. if their decision is paying off.The county voted in January 2016 to enter into a three-year contract with Ambulance Medical Billing (AMB), a national ambulance billing firm that specializes in obtaining payment for services provided by ambulance departments. A changeover took approximately four months.EMS director Preston Denney informed the county Safety Committee on Monday night he has arranged a presentation.“I talked with AMB,” said Denney. “I wasn’t able to get them here tonight, but I have it set up for next month.