BACKGROUND: Resources such as computed tomography (CT) scanners are sometimes shared when separate adult and pediatric emergency departments (EDs) exist in proximity. OBJECTIVES: To assess the impact of American College of Surgeons Level I trauma verification of an adult ED on the timeliness of nontrauma CT scans in a pediatric and adult ED that share a CT scanner. METHODS: ED patient records were retrospectively reviewed to determine the time from order to completion of nontrauma CT scans. We compared the timeliness of CT scan completion between the year leading up to the adult ED being verified as a Level I Trauma Center (2015), and the 2 subsequent years (2016-2017). RESULTS: The median time for nontrauma CT completion in the adult ED prior to Level I verification was 39 min, compared with 50 min and 49 min for the subsequent 2 years (p < 0.001). Similarly, the median time for completion of nontrauma CT scans in the pediatric ED increased from 33 min to 41 min and 39 min (p < 0.001). The proportion of patients who received CT scans within 30 min from order decreased after adult ED trauma upgrade, from 40% in 2015 to 30% and 32% (p < 0.001) in the 2 subsequent years. The pediatric ED showed similar results, with 48% of patients receiving CT scans within 30 min in 2015, compared with 34% in 2016 and 35% in 2017 (p < 0.001). CONCLUSIONS: Level I trauma verification of the adult ED adversely affected the timeliness of nontrauma CT scans in the EDs.