OBJECTIVES: To (1) define a single institution's rate of open reduction for operative pediatric supracondylar humerus (SCH) fractures; (2) describe variability by surgeon in rates of irreducible fracture (IRF) and open reduction; and (3) determine whether variation in opening rate correlated with surgeon experience. DESIGN: Retrospective analytic study. SETTING: Urban tertiary care Level 1 trauma center. PATIENTS/PARTICIPANTS: Twelve fellowship-trained pediatric orthopaedists. MAIN OUTCOME MEASUREMENTS: Rate of open reduction for operatively treated SCH fractures (OTA/AO 13-M/3). RESULTS: One thousand two hundred twenty-nine type II SCH fractures (none of which required open reduction) were excluded from the analysis. A total of 1365 other SCH fractures were included: 1302 type III fractures, 27 type IV fractures, and 36 fractures with unspecified type. 2.9% of type III and 22.2% of type IV fractures required open reduction. None of the injuries with unspecified type required open reduction. The rate of open reduction among 11 surgeons ranged from 0% to 15.0% in type III-IV fractures (P = 0.001). 86% (38/44) of open reductions were performed for IRF. In regression analysis, patient age was associated with open reduction for IRF (odds ratio 1.22, P = 0.001), but surgeon years-in-practice (0.321) and number of previous cases (0.327) were not associated with open reduction. Other indications for opening included suspected vascular or neurologic injury. CONCLUSIONS: Open reduction was rarely performed in this sample, but IRF was the dominant indication for opening. We found true variation in surgeons' rates of performing open reductions. More experience was not correlated with decreased likelihood of open reduction. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.