OBJECTIVES The authors hypothesized that a new strategy, termed the independent-capacity protocol (ICP), which was defined as primary stabilization at the emergency department (ED) and utilization of community resources via transfer to local hospitals, would reduce ED overcrowding without requiring additional hospital resources. METHODS This is a before-and-after trial that included all patients who visited an urban, tertiary care ED in Korea from July 2006 to June 2008. To improve ED throughput, introduction of the ICP gave emergency physicians (EPs) more responsibility and authority over patient disposition, even when the patients belonged to another specific clinical department. The ICP utilizes the ED as a temporary, nonspecific place that cares for any patient for a limited time period. Within 48 hours, EPs, associated specialists, and transfer coordinators perform secondary assessment and determine patient disposition. If the hospital is full and cannot admit these patients after 48 hours, the EP and transfer coordinators move the patients to other appropriate community facilities. We collected clinical data such as sex, age, diagnosis, and treatment. The main outcomes included ED length of stay (LOS), the numbers of admissions to inpatient wards, and the mortality rate. RESULTS A total of 87,309 patients were included. The median number of daily patients was 114 (interquartile range [IQR] = 104 to 124) in the control phase and 124 (IQR = 112 to 135) in the ICP phase. The mean ED LOS decreased from 15.1 hours (95% confidence interval [CI] = 14.8 to 15.3) to 13.4 hours (95% CI = 13.2 to 13.6; p < 0.001). The mean LOS in the emergency ward decreased from 4.5 days (95% CI = 4.4 to 4.6 days) to 3.1 days (95% CI = 3.0 to 3.2 days; p < 0.001). The percentage of transfers from the ED to other hospitals decreased from 3.5% to 2.5% (p < 0.001). However, transfers from the emergency ward to other hospitals increased from 2.9% to 8.2% (p < 0.001). Admissions to inpatient wards from the ED were significantly reduced, and admission from the emergency ward did not change. The ED mortality and hospital mortality rates did not change (p = 0.15 and p = 0.10, respectively). CONCLUSIONS After introduction of the ICP, ED LOS decreased without an increase in hospital capacity.