This study examined the psychometric properties of the DSM-oriented scales of the Child Behavior Checklist (Achenbach, Dumenci, & Rescorla, 2003) using confirmatory factor analysis to compare the six-factor structure of the DSM-oriented scales to competing models consistent with developmental theories of symptom differentiation. We tested these models on both clinic-referred (N = 757) and school-based, nonreferred (N = 713) samples of youths in order to assess the generalizability of the factorial structures. Although previous research has supported the fit of the six-factor DSM-oriented structure in a normative sample of youths ages 7 to 18 (Achenbach & Rescorla, 2001), tripartite model research indicates that anxiety and depressive symptomology are less differentiated among children compared to adolescents (Jacques & Mash, 2004). We thus examined the relative fit of a six- and a five-factor model (collapsing anxiety and depression) with younger (ages 7–10) and older (ages 11–18) youth subsamples. The results revealed that the six-factor model fit the best in all samples except among younger nonclinical children. The results extended the generalizability of the rationally derived six-factor structure of the DSM-oriented scales to clinic-referred youths and provided further support to the notion that younger children in nonclinical samples exhibit less differentiated symptoms of anxiety and depression.