The publication of To Err Is Human in 1999 drew national attention to the issue of patient safety and is often credited with catalyzing widespread efforts to reduce health care–related harm. At the time of the report's publication, central line–associated bloodstream infections (CLABSIs) were considered unpreventable. However, subsequent public reporting programs and the trend toward nonpayment for preventable harm have led not only to a significant reduction in CLABSIs, but a decrease in other types of hospital-acquired conditions as well. This directly translates into improved patient outcomes and reduced health care costs. This commentary highlights progress made in patient safety and suggests that future efforts should focus on improving the measurement of adverse events and mitigating diagnostic error. A past PSNet perspective discussed the evolution of patient safety as it relates to surgery.