Central catheter-associated bloodstream infections (CLABSIs) and catheter-associated urinary tract infections (CAUTIs) increase morbidity, mortality, and health care costs in pediatric patients. To examine changes over time in CLABSI and CAUTI rates between 2013 and 2018 in neonatal intensive care units (NICUs) and pediatric intensive care units (PICUs) using prospective surveillance data from community hospitals, children's hospitals, and pediatric units within general hospitals. This time series study included 176 US hospitals reporting pediatric health care-associated infection surveillance data to the National Healthcare Safety Network from January 1, 2013, to June 30, 2018. Patients aged 18 years or younger admitted to PICUs or level III NICUs were included in the analysis. The primary outcomes were device-associated rates of CLABSI in NICUs and PICUs and CAUTI in PICUs (infections per 1000 device-days). Secondary outcomes included population-based rates (infections per 10 000 patient-days) and device utilization (device-days per patient-days). Regression models were fit using generalized estimating equations to assess yearly changes in CLABSI and CAUTI rates, adjusted for birth weight (≤1500 vs >1500 g) in neonatal models. Of the 176 hospitals, 132 hospitals with NICUs and 114 hospitals with PICUs contributed data. Of these, NICUs reported 6 064 172 patient-days and 1 363 700 central line-days and PICUs reported 1 999 979 patient-days, 925 956 central catheter-days, and 327 599 indwelling urinary catheter-days. In NICUs, there were no significant changes in yearly trends in device-associated (incidence rate ratio [IRR] per year, 0.99; 95% CI, 0.95-1.03) and population-based (IRR, 0.96; 95% CI, 0.92-1.00) CLABSI rates or central catheter utilization (odds ratio [OR], 0.97; 95% CI, 0.95-1.00). Results were similar in PICUs, with device-associated (IRR, 1.03; 95% CI, 0.99-1.07) and population-based (IRR, 1.03; 95% CI, 0.99-1.07) CLABSI rates and central catheter utilization (OR, 0.99; 95% CI, 0.97-1.01) remaining stable. While device-associated CAUTI rates in PICUs also remained unchanged over time (IRR, 0.97; 95% CI, 0.91-1.03), population-based CAUTI rates significantly decreased by 8% per year (IRR, 0.92; 95% CI, 0.86-0.98) and indwelling urinary catheter utilization significantly decreased by 6% per year (OR, 0.94; 95% CI, 0.91-0.96). Recent trends in CLABSI rates noted in this study among critically ill neonates and children in a large cohort of US hospitals indicate that past gains have held, without evidence of further improvements, suggesting novel approaches for CLABSI prevention are needed. Modest improvements in population-based CAUTI rates likely reflect more judicious use of urinary catheters.