Long work hours and fatigue among health care workers can adversely impact patient safety. In 2011, the Accreditation Council for Graduate Medical Education made changes to resident duty hours, but research on the effect of those reforms on resident wellness and patient safety remains somewhat inconclusive. In this retrospective observational study, researchers examined the impact of the 2011 duty hour reforms on patient mortality, length of stay, and cost using data on patients hospitalized in the 2-year periods before and after the work hour changes were implemented. Nonteaching hospitals served as the control group. They found no difference in mortality or length of stay but did find that cost associated with hospitalization decreased slightly at teaching hospitals after the 2011 changes. A past PSNet interview discussed the effect of less restrictive duty hours on patients and residents.