Leape L, Berwick D, Clancy C, et al. Transforming healthcare: A safety imperative. Quality and Safety in Health Care. 2009;18:424-428.Ten years after the Institute of Medicine report To Err Is Human that described the scope and impact of medical errors in the US, the Lucian Leape Institute reflects on progress toward improving patient safety. This article identifies five concepts that are fundamental to achieving meaningful improvement in health care system safety: transparency, care integration, patient/consumer engagement, restoration of joy and meaning in work, and medical education reform.