In 2003, the Accreditation Council for Graduate Medical Education limited resident physician work hours to 30 hours in 1 shift and 80 hours in 1 week. These duty hour reforms were intended to enhance patient safety and trainee physician well-being. However, some have expressed concern that physicians who train for fewer hours will leave residency less skilled and ultimately provide lower quality care. Investigators assessed whether attending internists who trained with duty hour restrictions differed after residency in terms of their Medicare patients' mortality, readmissions, or costs when compared with internists who trained with unlimited duty hours. They found no difference in quality or cost between the two physician groups. Although other studies have concluded that duty hours have not adversely affected clinical or safety outcomes in residency, this study extends that finding to physicians' subsequent practice. Duty hour restrictions have consistently been associated with improved resident physician well-being. A PSNet perspective reviewed changes to the ACGME requirements to create flexibility for work hours within the maximum 80-hour workweek.