OBJECTIVE: To determine the total cost for a 30-day episode of care for high-energy tibial plateau fractures and the aspects of care associated with total cost. DESIGN: Time-driven activity-based costing analysis. SETTING: One Level 1 adult trauma center. PATIENTS: One hundred twenty-one patients with isolated, bicondylar tibial plateau fractures undergoing staged treatment were reviewed. PRIMARY OUTCOME: Total cost. RESULTS: A total of 85 patients were included and most sustained Schatzker VI fractures (n = 66, 77%). All patients were treated with biplanar external fixation before definitive fixation. A total of 26 patients (31%) were discharged to skilled nursing facilities, and 37 patients (43%) were not discharged between procedures. Total cost for a 30-day episode of care was $22,113 ± 4056. External fixation components ($5952, 26.9%), length of hospital stay ($5606, 25.4%), discharge to skilled nursing facility (SNF) ($3061, 13.8%), and definitive fixation implants ($2968, 13.4%) contributed to the total cost. The following were associated with total cost: patient discharged to SNFs (P < 0.001), patient remaining inpatient after external fixation (P < 0.001), days of admission for open reduction internal fixation (ORIF) (P = 0.005), days spent with external fixation (P < 0.001), days in a SNF after ORIF (P < 0.001), and external fixation component cost (P < 0.001). CONCLUSIONS: External fixation component selection is the largest contributor to cost of a 30-day episode of care for high-energy bicondylar tibial plateau fractures. Reduction in cost variability may be possible through thoughtful use of external fixation components and care pathways. LEVEL OF EVIDENCE: Economic analyses Level IV. See Instructions for Authors for a complete description of levels of evidence.