Objective: To identify how hospital discharge data could discriminate the distribution patterns of high-risk trauma children in mandated and non-mandated trauma systems. Methods: Hospital discharge data of pediatric trauma patients 1 - 15 years of age in Florida (FL), USA—[a mature mandated trauma system with certified trauma centers (TCs)] and in Indiana (IN), USA—(an immature non-mandated trauma system) admitted both to trauma center (TC) and non-TC healthcare facilities were analyzed. The injury severity score (ISS) measurement was used to verify injury severities. Results: Analysis showed that the majority of admissions were mild injuries (ISS = 1 - 8), [FL 70%, IN 66%, odds ratio (OR) 1.2, 95% confidence interval (CI) 1.1, 1.3]. Florida trauma children (all severities) generally receive TC care more frequently than Indiana’s (OR = 1.8, CI 1.6 - 1.9). Particularly admission to TCs with severe (ISS ≥ 25) pelvic injury was greater in Florida (OR 3.5, CI 1.6 - 7.4). Florida, encountered some other severe injury mechanisms (motor vehicle accidents, falls) more frequently than Indiana (ORs and CI: 2.2, 1.5 - 3.3 and 3.1, 1.1 - 8.7, respectively). Conclusions: Hospital discharge data can demonstrate the expected patient distribution difference when comparing a mature trauma system with a voluntary evolving system. The level of maturity of the adopted trauma system often influences such difference.