Anesthesiologists often must oversee multiple surgeries. This study evaluated adult patients from 23 US academic and private hospitals who underwent major surgery between 2010, and 2017, to examine anesthesiologist staffing ratios against patient morbidity and mortality. The authors categorized the staffing into four groups based on the number of operations the anesthesiologist was covering. The study found that increased anesthesiologist coverage was associated with greater risk-adjusted morbidity and mortality of surgical patients. Hospitals should consider evaluating anesthesiology staffing to determine potential increased risks.