Despite numerous potential benefits of outpatient surgery, there is currently a lack of national benchmarking data available for hospitals and surgeons to compare their own outcomes as they transition toward outpatient surgery. Patients who underwent 14 common general surgery operations from 2016-2020 were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Operations were selected based on frequency and the ability to be performed both in- and outpatient. Postoperative complications and readmissions were compared between patients who underwent inpatient vs outpatient surgery. After adjusting for patient comorbidities, multivariable models assessed the effect of patient characteristics on the odds of experiencing postoperative complications. A separate multiinstitutional study of 21 affiliated hospitals assessed practice variation. In 13 of the 14 studied procedures, complications were lower for patients who were selected for outpatient surgery (all P<0.01); minimally invasive (MIS) adrenalectomy showed no difference (P=0.61). Multivariable analysis confirmed these findings; the odds of experiencing any adverse events were lower following outpatient surgery in all operations but MIS adrenalectomy (OR 0.97; 95% CI 0.47-2.02). Analysis of institutional practices demonstrated variation in the rate of outpatient surgery in certain breast, endocrine, and hernia repair operations. Institutional practice patterns may explain the national variation in the rate of outpatient surgery. While the present data does not support the adoption of outpatient surgery to less optimal candidates, addressing unexplained practice variations could result in improved utilization of outpatient surgery.