Level I trauma centers serve as a community resource, with most centers using an inclusive transfer policy that may result in overtriage. The financial burden this imparts on an urban trauma system has not been well examined. We sought to examine the incidence of secondary overtriage (SOT) at an urban Level I trauma center. This was a retrospective study from an urban Level I trauma center examining patients admitted as trauma transfers (TT) from 2010 to 2014. SOT was defined as patients not meeting the "Orange Book" transfer criteria and who had a length of stay of <48 hours. Average ED and transport charges were calculated for total transfer charges. A total of 2397 TT were treated. The number of TT increased over the study interval. The mean age of TT was 59.7 years (SD ± 26.4 years); patients were predominantly male (59.2%), white (83.2%), with at least one comorbidity (71.5%). Blunt trauma accounted for 96.8 per cent of admissions with a median Injury Severity Score of nine (IQR: 5-16). Predominant injuries were isolated closed head trauma (61.4%), skin/soft tissue injury (18.9%), and spinal injury (17.6%). SOT was 48.2 per cent and increased yearly (P < 0.001). The median trauma center charge for SOT was ($27,072; IQR: $20,089-34,087), whereas ED charges were ($40,440; IQR: $26,150-65,125), resulting in a total cost of $67,512/patient. A liberal TT policy results in a high SOT rate adding significant unnecessary costs to the health-care system. Efforts to establish transfer guidelines may allow for significant cost savings without compromising care.