Given the limited information on positive developmental outcomes for youth after justice system involvement, the present study aimed to identify patterns of gainful (i.e., career and education) expectations and behavior with 1,110 male and female youth adjudicated for a serious offense through group-based trajectory modeling. Using the Pathways to Desistance data set, we assessed whether expectation and behavior groups differed on demographic, peer, or romantic partner characteristics and modeled the codevelopment of expectations and behaviors through dual trajectory modeling. Approximately 30% of youth positively changed their expectations or behaviors after system involvement. Peer characteristics more robustly differentiated expectation and behavioral groups than romantic partner characteristics. The dual trajectory model presented a clear picture of developmental paths for youth with consistently low and high expectations for and engagement in gainful behaviors, but an unclear picture on how moderate or changing expectations and behavior codevelop. Overall, the results suggest it is important to consider the potential for positive change in juvenile justice dispositions. (PsycInfo Database Record (c) 2025 APA, all rights reserved).