The use of fenestrated and branched endografts for the treatment of complex aortic aneurysms is increasing. Despite the low morbidity and mortality associated with these repairs, reintervention rates in the midterm and long term remain a concern. The purpose of this study was to investigate our experience with reinterventions after fenestrated and branched endovascular aneurysm repair (F/BEVAR). We performed a retrospective analysis of all patients treated with F/BEVAR at our institution during the years 2009 to 2019. Among them, we identified those who required reinterventions during the period of follow-up. Data collected included patients' demographics, type of treated aneurysm, indications for reintervention, and methods of repair. During the study period, 47 patients underwent F/BEVAR. A total of 160 branches were placed. Of those, 12 patients (25%) underwent 15 secondary interventions for late-occurring complications. Among those requiring reinterventions, mean age was 70 years (range, 59-80 years), and 10 (83%) were male. The majority of those requiring reinterventions were treated for thoracoabdominal aortic aneurysms. Mean time to reintervention was 14 months (range, 2-32 months). Indications for reinterventions included separation of side branches from fenestrations (nine), separation of side branches (three), type IA endoleak (one), type II endoleak (one), and limb occlusion (one). All endoleaks were detected on routine follow-up imaging. All reinterventions were performed using endovascular techniques. Mean follow-up after reinvention was 22 months (range, 1-53 months). During this period, no patient required open conversion. Follow-up imaging revealed successful obliteration of the endoleak, and none experienced continued growth of the sac. Reinterventions after F/BEVAR are not uncommon. The majority of reinterventions are performed for endoleaks that are due to failure at the level of the fenestrations or component separation. These endoleaks can be treated successfully with endovascular methods and do not require open conversion. Because of the possibility of development of late endoleaks, continual monitoring of these patients is required after the primary procedure. Copyright © 2019 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.