Background: Postoperative transcatheter interventions (TCIs) are performed after congenital heart surgery to treat residual or recurrent anatomic lesions. We used the Society of Thoracic Surgeons Congenital Heart Surgery Database to evaluate rates of postoperative TCIs, center variability, and to determine whether center approaches to postoperative TCI might be associated with outcomes. Methods and Results: Patients <18 years undergoing an index operation (2010–2016) were included. We determined predischarge postoperative TCI rates and used multivariable modeling, adjusting for patient factors and case complexity, to evaluate the association between center risk-adjusted postoperative TCI rates and risk-adjusted outcomes (operative mortality, post-TCI mortality, and failure-to-rescue). Postoperative TCI was performed after 2615/105 742 (2.5%) index operations and after 1443/25 416 (5.7%) highest complexity operations (STAT [Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Score] Mortality Category 4 and 5). Median (interquartile range) age of patients undergoing TCI was 2.7 (0.2–8.0) months with 43% performed in neonates. There was a wide center variability across the 107 included centers with risk-adjusted rates of postoperative TCI ranging from 0.0% to 8.0% overall and 0.0% to 20.7% for STAT 4 and 5 cases. Postoperative TCI was associated with higher risk-adjusted odds of operative mortality (odds ratio, 4.06; 95% CI, 3.60–4.58). Centers with higher postoperative TCI rates had higher overall operative mortality ( R ² =0.23; P =0.02) but did not have higher post-TCI mortality ( P =0.10). There was no correlation between center TCI rates and failure-to-rescue ( P =0.19). Conclusions: Patients undergoing postoperative TCI represent a high-risk cohort. Wide center variability suggests the potential for improving outcomes, but further study is necessary to better understand optimal approaches.