Introduction: Bed boarding of admitted patients in the Emergency Department (ED) is widely recognized as a major contributor to overcrowding, particularly in very high-volume hospitals. The issue of bed boarding is directly tied to hospital-wide capacity, flow and operations. Early morning discharge from inpatient units has been identified as a low-cost intervention to decrease bed boarding, as it allows earlier transfer of admitted patients from the ED. Several hospitals have instituted discharge before noon, or discharge before 10AM policies, practices and targets. Our objectives were 1) to assess the current status of flow within 3 high-volume community hospitals with respect to time of day of discharges from the in-patient units and time of day of transfers from the ED to in-patient units, and 2) to assess the association between time of transfer from the ED and total ED Length of Stay (EDLOS) of admitted patients. Methods: We conducted a retrospective multi-centre observational study during the period of January 1, 2015 to December 31, 2015 at three high-volume community hospitals within Ontario, Canada. All patients admitted to the Medicine service were identified. Time of discharge from the in-patient units and time of transfer from the ED were collected for all patients. EDLOS was calculated for all patients as a function of time of transfer from the ED. Results: Preliminary findings show that, for the three community hospitals, only 11.7% - 19.6% of admitted patients were discharged from the in-patient units during the period between 6AM and 12PM, with a peak discharge time of 2PM in all three hospitals. A concurrent lag was observed in the time of transfer of patients from the ED, with peak transfer times occurring the late afternoon between 3PM and 9PM, and coinciding with a peak in patient volume in the ED. Patients transferred out of the ED earlier in the day (between 12AM 11:59AM) had between 1.4 hours to 8.0 hours lower mean EDLOS when compared to those patients transferred later in the day (between 12PM 11:59PM). Conclusion: Hospital-wide flow and operational issues have a significant impact on ED bed boarding, and potential efficiencies seem at the current time to be underutilized. Interventions aimed at optimizing flow must be implemented alongside those aimed at increasing capacity in order to improve bed boarding. ** These findings are best communicated in graphic form to better represent the dynamics of the flow in and out of the ED over a 24-hour period, and will be presented in graphic format if selected for the conference.