The Accreditation Council for Graduate Medical Education (ACGME) restrictions on resident work hours have improved resident well-being, but the impact on education, clinical and patient safety outcomes is less clear. This meta-analysis found that the 2003 ACGME restrictions (limiting residents to 80-hour work weeks and 28-hour shifts) was associated with an 11% reduction in mortality; however, there was no significant difference in mortality after the 2011 restrictions (limiting first-year residents to 16-hour shifts). These findings reinforce the impact of extended resident physician work hours and patient morbidity and mortality. The authors also recommend that future research examine the relationship between work hours and patient outcomes among other health care workers.