Background: Antibiotic time outs (ABTOs), formal reassessments of all new antimicrobial regimens by the care team, can optimize antimicrobial regimens, reducing antimicrobial overuse and potentially improving outcomes. Implementation of ABTOs is a substantial challenge. We used quality improvement methods to implement robust, meaningful, team-driven ABTOs in general medicine ward services. Methods: We identified and engaged stakeholders to serve as champions for the quality improvement initiative. On October 1, 2018, 2 internal medicine teaching services (services A and B), began conducting ABTOs on all patients admitted to their services receiving systemic antimicrobials for at least 36 hours. Eligible patients were usually identified by the team pharmacist. ABTOs were completed within 72 hours of antibiotic initiation and were documented in the electronic medical record (EMR) by providers using a template. The process was modified as necessary in response to feedback from frontline clinicians using plan-do-study-act (PDSA) methods. We subsequently spread the project to 2 additional internal medicine services (services C and D); 2 family medicine teams (services E and F); and 1 general pediatric service (service G). The project is ongoing. We collected data for the following metrics: (1) proportion of ABTO-eligible patients with an ABTO; (2) proportion of ABTOs conducted within the recommended time frame; (3) documented plan changes as a result of ABTO (eg, change IV antibiotics to PO); (4) proportion of documented plan changes actually completed within 24 hours. Results: Within 12 weeks, services A and B were successfully completing time outs in >80% of their patients. This target was consistently reached by services C, D, E, F, and G almost immediately following launch on those services. As of June 29, 2019, >80% of eligible patients across all participating services have had a time out conducted for 16 consecutive weeks. ABTOs have resulted in a change in management in 35% of cases, including IV-to-PO change in 19% of cases and discontinuation in 5%. Overall, 77% of time outs occurred during the 36–72-hour window. Ultimately, 95% of documented plan changes were completed within 24 hours. Conclusions: ABTOs are effective but implementation is challenging. We achieved high compliance with ABTOs without using electronic reminders. Our results suggest that ABTOs were impactful in the non–critical-care general medicine setting. Next steps include (1) development of EMR-based tools to facilitate identifying eligible patients and ABTO documentation; (2) continued spread through our health care system; and (3) analysis of ABTO impact using ABTO-unexposed patients as a control group.