AIMS: This study evaluated from a US payer perspective the cost-effectiveness of two chimeric antigen receptor T (CAR T) cell therapies, axicabtagene ciloleucel (axi-cel) versus lisocabtagene maraleucel (liso-cel), for the treatment of adult patients with relapsed or refractory (r/r) large B-cell lymphoma (LBCL) following two or more systemic therapy lines. METHODS: We developed a 3-state (i.e., pre-progression, post-progression, death) partitioned survival model to estimate patients' lifetime outcomes. Mixture cure models were used for survival extrapolation to account for long-term remission. Survival inputs were based on a matching-adjusted indirect comparison (MAIC) that reweighted the ZUMA-1 population (receiving axi-cel) to match patient characteristics in TRANSCEND-NHL-001 (assessing liso-cel). Costs included apheresis, drug acquisition, and administration for conditioning chemotherapy and CAR T therapies, monitoring, transplant, hospitalization, adverse events, routine care, and terminal care, per published literature and databases. Utilities were derived from ZUMA-1 and literature. Deterministic and probabilistic sensitivity analyses were conducted. RESULTS: In the base case, axi-cel was associated with more QALYs (7.76 vs. 5.94) and greater costs overall ($611,440 vs. $597,174) than liso-cel, at $7,843/QALY gained. The incremental costs (+$14,266) were largely driven by higher routine care costs (+$18,596) due to longer survival and hospitalization (+$10,993) but partially offset by reduced costs of CAR T acquisition (‒$11,300) and terminal care (‒$4,025). Sensitivity analyses consistently suggested robustness of base-case results. LIMITATIONS: This study relied on an MAIC in which trial design differences and unobserved confounders could not be accounted for. Future real-world studies for recently approved CAR T are warranted to validate our results. Due to a lack of data, we assumed equivalent use of transplants and treatment for B-cell aplasia between the two therapies based on clinicians' opinions. CONCLUSIONS: In the US, axi-cel is a potentially cost-effective treatment option compared with liso-cel for adult patients with r/r LBCL after two or more systemic therapy lines.