Considerable controversy exists around the optimal age on which to operate for craniosynostosis. This study aims to use data from the American College of Surgeons National Surgical Quality Improvement Program-Pediatric to assess the impact of operative age on hospital stay and outcomes. After excluding patients who underwent endoscopic cranial vault remodeling, a total of 3292 patients met inclusion criteria in the National Surgical Quality Improvement Program-Pediatric between 2012 and 2019. Median age at surgery was 300 days (interquartile range: 204-494). Patients between 0 and 6 months underwent the highest proportion of complex cranial vault remodeling, Current Procedural Terminology 61,558 (n = 44, 7.7%) and Current Procedural Terminology 61,559 (n = 317, 55.1%). White blood cell counts peaked in the 12 to 18 months group, and were lowest in the 24 ± months group. Hematocrit was lowest in the 0 to 6 months group and rose steadily to the 24 ± months group; the inverse pattern was found in platelet concentration, which was highest in the youngest patients and lowest in the oldest. Prothrombin time, international normalized ratio, and partial thromboplastin time were relatively consistent across all age groups. Younger patients had significantly shorter operating room times, which increased with patient age (P < 0.001). Younger patients also had significantly shorter length of stay (P = 0.009), though length of stay peaked between 12 and 18 months. There was a significantly lower rate of surgical site infection in younger patients, which occurred in 0.7% of patients 0 to 12 months and 1.0 to 3.0% in patients over 12 to 24 ± months. There was no significant difference in the average number of transfusions required in any age group (P = 0.961).