BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most common malignancy of childhood. With the introduction of novel cellular therapies, cost of care is a critical component and financial toxicity experienced by patients and society requires evaluation. This study aims to assess the total cost of CAR-T therapy for pediatric ALL patients with commercial insurance coverage in the United States. STUDY DESIGN: Using de-identified commercial insurance data from the OptumLabs ^® Data Warehouse, a cohort of 37 patients, aged 1-25 years, with B-ALL treated with CAR-T therapy between Oct 2016 and Dec 2021 in the United States was identified. Cost was evaluated for a 90 day period encompassing CAR-T infusion and by administration and complication characteristics. RESULTS: Among the 37 identified ALL patients that received a CAR-T product infusion, 14 patients were female, median age at administration was 13 years. The median 90-day total cost was $620,500 (Mean: $589,108). Inpatient cost accounted for approximately 71% of the total cost with an average of 28 inpatient days per patient. Although inpatient cost was slightly higher in the older age group (aged 10-25 years) and in patients with a code for CRS, these differences were not statistically significant. CONCLUSION: This real-world cost analysis shows for the first time the encompassing cost of CAR-T therapy for pediatric ALL patients in the US with commercial insurance. This study provides a valuable benchmark that can be used to analyze the financial implications of CAR-T therapy for pediatric ALL therapy on health systems.