Background: Differences in survival and morbidity among treatment options (ablation, surgical resection, and transplant) for early-stage hepatocellular carcinoma (HCC) have been well-studied. Additional understanding of the costs of such care would help to identify drivers of high costs and potential barriers to care delivery. Objective: To quantify total and patient out-of-pocket costs for ablation, surgical resection, and transplant in the management of early-stage HCC and to identify factors predictive of these costs. Methods: This retrospective U.S. population-based study used the SEER-Medicare linked dataset to identify a sample of 1067 Medicare beneficiaries (mean age, 73 years; 674 men, 393 women) diagnosed with early-stage HCC (size ≤5 cm) treated with ablation (N=623), resection (N=201), or transplant (N=243) between January 2009 and December 2016. Total costs and patient out-of-pocket costs for the index procedure as well as for any care within 30 days and 90 days post-procedure were identified and stratified by treatment modality. Additional comparisons were performed among propensity-score matched subgroups of patients treated by ablation or resection (each N=172). Multivariable linear regression models were used to identify factors predictive of total costs and out-of-pocket costs for index procedures as well as for 30-day and 90-day post-procedure periods. Results: For ablation, resection, and transplant, median index-procedure total cost was $6689, $25,614, and $66,034; index-procedure out-of-pocket cost was $1235, $1650, and $1317; 30-day total cost was $9456, $29,754, and $69,856; 30-day out-of-pocket cost was $1646, $2208, and $3198; 90-day total cost was $14,572, $34,984, and $88,103; and 90-day out-of-pocket cost was $2138, $2462, and $3876, respectively (all p<.001). In propensity-matched subgroups, ablation and resection had median index-procedure, 30-day, and 90-day total costs of $6690 and $25,716, $9995 and $30,365, and $15,851 and $34,455, respectively. In multivariable analysis adjusting for socioeconomic factors, comorbidities, and liver-disease prognostic indicators, surgical treatment (resection or transplant) was predictive of significantly greater costs compared with ablation at all time points. Conclusion: Total and out-of-pocket costs for index procedures as well as for 30-day and 90-day post-procedure periods were lowest for ablation, followed by resection and then transplant. Clinical Impact: This comprehensive cost analysis could help inform future cost-effectiveness analyses.