This retrospective study estimated postinfusion health care resource utilization (HCRU) by site of care among 303 patients with relapsed/refractory large B-cell lymphoma who received third- or later-line treatment with lisocabtagene maraleucel (liso-cel) in the TRANSCEND NHL 001 and OUTREACH trials. Inpatients ( = 256) had higher rates of hospitalization versus outpatients ( = 47; >99% vs 62%), by definition, and higher rates of tocilizumab use for cytokine release syndrome and/or neurological events (22% vs 9%). Rates of intensive care unit admission, corticosteroid use, vasopressor use, hemodialysis, and intubation were generally low and similar between groups. Median (range) total hospital length of stay was 15 (0-88) days (inpatients) and 4 (0-77) days (outpatients). Over 6 months, estimated mean postinfusion cost of care was $89,535 (inpatients) and $36,702 (outpatients). Most costs were incurred in the first month post infusion (inpatients, $50,369 [56%]; outpatients, $19,837 [54%]). Lower overall HCRU was observed with outpatient postinfusion monitoring.