Background The treatment of 3- and 4-part proximal humeral fractures in the older adult is controversial. No study has directly compared reverse shoulder arthroplasty (RSA) with nonoperative treatment for these fractures. The purpose of this study was to compare clinical and patient-reported outcomes between RSA and nonoperative treatment groups. Methods A retrospective review was performed on all 3- and 4-part proximal humeral fractures treated with either RSA or nonoperative treatment with minimum 1-year follow-up. All patients in the nonoperative cohort were offered RSA but declined. Objective patient data were obtained from medical records. Patient-reported outcomes including visual analog scale score, Single Assessment Numeric Evaluation score, Penn Shoulder Score, American Shoulder and Elbow Surgeons score, resiliency score, and Veterans Rand-12 scores were obtained at follow-up. Statistical analysis was performed by use of the Student t test for continuous variables and χ2 analysis for nonparametric data. Results We analyzed 19 nonoperative and 20 RSA patients with a mean follow-up period greater than 2 years (29 months in nonoperative group and 53 months in RSA group). There were no differences in range of motion between groups (forward elevation, 120° vs 119° [P = .87]; external rotation, 23° vs 31° [P = .06]). No differences between the nonoperative and RSA groups were noted for any patient-reported outcomes. Among patients receiving RSA, there was no difference in outcomes in those undergoing surgery less than 30 days after injury versus those receiving delayed RSA. Conclusions This study suggests that there are minimal benefits of RSA over nonoperative treatment for 3- and 4-part proximal humeral fractures in older adults.