BACKGROUND: Subtrochanteric femur fractures associate with a relatively high complication rate and are traditionally treated operatively with a period of limited weight bearing. Transitioning from extramedullary to intramedullary implants, there are increasing biomechanical and clinical data to support early weight bearing. This multicenter retrospective study examines the effect of postoperative weight bearing as tolerated (WBAT) for subtrochanteric femur fractures. We hypothesize that WBAT will result in a decreased length of stay (LOS) without increasing the incidence of re-operation. METHODS: This study assesses total LOS and postoperative LOS after intramedullary fixation for subtrochanteric fractures between postoperative weight bearing protocols across 6 level I trauma centers (n = 441). Analysis techniques consisted of multivariable linear regression and nonparametric comparative tests. Additional subanalyses were performed, targeting mechanism of injury (MOI), Winquist-Hansen fracture comminution, 20-year age strata, and injury severity score (ISS). RESULTS: Total LOS was shorter in WBAT protocol within the overall sample (7.4 vs 9.7 days; p < 0.01). Rates of re-operation were similar between the two groups (10.6% vs 10.5%; p = 0.99). Stratified analysis identified patients between ages 41-80, WH comminution 2-3, high MOI, and ISS between 6-15 and 21-25 to demonstrate a significant reduction in LOS as a response to WBAT. CONCLUSION: An immediate postoperative weight bearing as tolerated protocol in patients with subtrochanteric fractures reduced length of hospital stay with no significant difference in reoperation and complication rates. If no contraindication exists, immediate weight bearing as tolerated should be considered for patients with subtrochanteric femur fractures treated with statically locked intramedullary nails. LEVEL OF EVIDENCE: Therapeutic Level III.