BACKGROUND: Patient-reported outcome measures are a valuable tool to evaluate an intervention from a patient's perspective. Previous evidence shows that, while resident involvement may increase operative times, it does not affect complications or patient-reported outcomes. This study sought to assess the impact of a new residency program on patient-reported outcome measures, operative time, and complication rates in total shoulder arthroplasty. MATERIALS AND METHODS: A retrospective cohort study was performed of patients who underwent total shoulder arthroplasty at a single health care system. Demographic data, resident presence during shoulder arthroplasty, arthroplasty type, procedure duration, complications, and American Shoulder and Elbow Surgeons (ASES) score change were collected. Patients 18 years or older who underwent primary anatomic or reverse total shoulder arthroplasty were included. Patients who did not meet the inclusion criteria, had a preoperative diagnosis other than primary osteoarthritis, lacked preoperative and postoperative ASES scores, and canceled procedures were excluded. RESULTS: A total of 139 patients were identified and included in our analysis. Ninety-seven total shoulder arthroplasties were performed with a resident not present, and 42 with a resident present. This study showed no significant effects of the presence or absence of a resident on ASES scores, complication rates, or surgery times. CONCLUSION: This study adds to previous evidence indicating that attending orthopedic surgeons can support resident learning and surgical skill development while maintaining patient-reported outcome measures, surgical time, and complication rates similar to those without resident involvement when performing shoulder arthroplasty. [