The Accreditation Council for Graduate Medical Education recently emphasized the importance of systems-based practice and systems-based learning; however, successful models of collaborative quality improvement (QI) initiatives in residency training curricula are not widely available. Atlantic Health successfully conceptualized and implemented a QI collaborative focused on medication safety across eight residency training programs representing 219 residents. During a six-month period, key faculty and resident leaders from 8 (of 10) Atlantic Health residency training programs participated in three half-day collaborative learning sessions focused on improving medication reconciliation. Each session included didactic presentations from a multidisciplinary team of clinical experts as well as the application of principles that identified challenges, barriers, and solutions to QI initiatives. The learning sessions emphasized the fundamental principles of medication reconciliation, its critical importance as a vital part of patient handoff in all health care settings, and the challenges of achieving successful medication reconciliation improvement in light of work hours restrictions and patient loads. Each residency program developed a detailed implementation and measurement plan for individual "action learning" projects, using the Plan-Do-Study-Act method of improvement. Each program then implemented its QI project, and expert faculty (e.g., physicians, nurses, pharmacists, QI staff) provided mentoring between learning sessions. Several projects resulted in permanent changes in medication reconciliation processes, which were then adopted by other programs. The structure, process, and outcomes of this effort are described in detail.