Establishing interoperability through health information exchange (HIE) is expected to reduce health care costs and improve quality of care. These benefits are presumed to be associated with reductions in repeat testing and reduced rates of admission. Our institution utilizes Epic’s Care Everywhere, an HIE which functions on a combination of push and pull data exchanges with multiple neighboring institutions including 3 of the 4 regional academic institutions. When HIE data is available, an activity tab becomes viewable to the end user, but there are no prompts to review this information. We determined how frequently providers in our ED reviewed HIE data by activating this activity tab, and if the review of HIE data affected discharge length of stay (LOS), time to decision to admit (DTA), affected odds of discharge or reduced advanced imaging (CT, MRI, US). We examined results from 2 hospitals, 1 academic (AH) and 1 community (CH). We queried our electronic health record (EHR) for any patient presentation in the main ED, where any health care provider reviewed HIE data during a 1-year period from 4/1/17 to 4/30/18. We compared these results to those patients who did not have HIE data accessed. We excluded patients under 18 years, and lower acuity (ESI 4 and 5) patients. Times, dispositions, and rates of imaging orders were calculated for those patients with and without HIE information review. Results are presented as percent frequency of occurrence and 95% confidence intervals, with statistical analysis via Mann-Whitney test. There were 24,036 arrivals to CH and 29,843 arrivals to AH that met inclusion criteria. Of these 2,962 (12.3%) and 5,662 (18.9%) had HIE data accessed respectively. At both sites median LOS to discharge was longer for those with HIE data accessed: CH: 207.9 min (95% CI, 205.7 - 210.1) versus 225.3 min (217.0-241.4), p<0.001, and AH: 272.6 min (269.9-275.3) versus 300.7 min (292.5-309.9), p<0.001. DTA was longer when HIE data was accessed at AH (245.4 min [238.2 - 254.6] versus 234.4 min [230.3-240.3], p<0.001) but not different at CH (184.6 min [95% CI 179.9-191.8] versus 187.6 min [95% CI 183.3-191.5], p=0.5). Odds of discharge versus admission or observation were lower in those patients with HIE data accessed at both sites (CH 0.17 [95% CI 0.16-0.19] versus AH 0.28 [95% CI 0.26-0.3]). There were increased odds of receiving an imaging study for those without HIE at CH (1.3 [95% CI 1.2-1.4]) but not at AH (0.96 [95% CI 0.9-1.02]). Review of HIE information did not result in reducing ED care times, but at CH HIE review resulted in a decrease in odds of receiving an advanced image. Many factors may influence an ED provider to review HIE data, including the acuity and clinical condition of a patient. These characteristics may have biased our results, resulting in our finding of longer or unchanged ED care times for those patients with HIE review. Further research could examine more granular potential benefits of HIE use, when and how HIE influences medical imaging and explore ways to increase rates of HIE data review to determine if it is possible to attain the proposed benefits of this technology.