Background: Iron deficiency anemia (IDA) is a common complication of inflammatory bowel disease (IBD) and can result in reduced quality of life and increased healthcare costs. IDA is treated with iron supplementation, commonly with intravenous iron formulations, such as ferric carboxymaltose (FCM), and iron sucrose (IS). Methods: This study assessed the cost-effectiveness of FCM compared with IS, in terms of additional cost per additional responder in patients with IDA subsequent to IBD in the Spanish setting. An economic model was developed to assess the additional cost per additional responder, defined as normalization or an increase of ⩾2 g/dl in hemoglobin levels, for FCM versus IS from a Spanish healthcare payer perspective. Efficacy inputs were taken from a randomized controlled trial comparing the two interventions (FERGIcor). Costs of treatment were calculated in 2021 Euros (EUR) using a microcosting approach and included the costs of intravenous iron, healthcare professional time, and consumables. Cost-effectiveness was assessed over one cycle of treatment, with a series of sensitivity analyses performed to test the robustness of the results. Results: FCM was more effective than IS, with 84% of patients achieving a response compared with 76%. When expressed as number needed to treat, 13 patients would need to switch treatment from IS to FCM in order to achieve one additional responder. Costs of treatment were EUR 323 with FCM compared with EUR 470 with IS, a cost saving of EUR 147 with FCM. Cost savings with FCM were driven by the reduced number of infusions required, resulting in a reduced requirement for healthcare professional time and use of consumables compared with the IS arm. Conclusion: The present analysis suggests that FCM is less costly and more effective than IS for the treatment of IDA subsequent to IBD in Spain and therefore was considered dominant.