Medical errors remain too common in the delivery of healthcare despite substantial efforts of meany healthcare organizations.  Researchers who study organizations that face hazardous and turbulent task conditions, yet demonstrate sustained superior safety performance, attribute their achievement in large part to their culture of safety. Drawing on lessons from these “high reliability organizations” (HROs), policymakers interested in improving health care delivery have called upon health care organizations to strengthen their safety culture to reduce adverse events. Founded in 1999, the PSC is a national collaborative of healthcare researchers, organizations, and 150 public and private hospitals that aims to measure and compare the safety culture of its members and to implement and evaluate approaches for improving safety practices.