The Child Sponsorship Program (CSP) is critical to enhancing the objective and subjective well-being of enrollees. Meanwhile, social work interventions emphasize scientific approaches aimed at empowering marginalized populations. This intervention research (IR) was focused on raising the psychological well-being (PWB) of adolescents in a prominent CSP located in Kochi, Kerala. Preliminary findings from a pilot study underscored the need for intervention, and subsequent Delphi survey results guided the formulation of an intervention strategy. Capitalizing on the transformative power of peer groups, IR implemented a social group work intervention to enhance adolescent PWB in CSP. Using a nonequivalent comparison group interrupted time-series design, the PWB of participants in the intervention group (IG, N = 20) and comparison group (CG, N = 20) was measured and compared. Ryff's PWB scale with 42 items served as the assessment instrument. Descriptive statistics confirmed the normal distribution of baseline data for all participants (N = 40), while repeated measures ANOVA in SPSS 25 validated the alternative hypothesis, indicating significant differences in PWB measures over time within IG and between IG and CG. Additionally, along with statistical evidence of intervention effectiveness, this study used a qualitative design for ongoing evaluation of the intervention process, providing insights for program refinement and demonstrating intervention outcomes. By defining a model for group work intervention among CSP adolescents to improve PWB, this study underscores the important role of social work interventions in empowering marginalized populations. Plain Language Summary: Improving mental health for vulnerable teens: Social work in child sponsorship programs The Child Sponsorship Program (CSP) plays a crucial role in improving the well-being of enrolled children, while social work interventions focus on empowering marginalized groups. This research aimed to boost the mental well-being of teenagers in a prominent CSP in Kochi, Kerala. After initial findings showed a need for intervention, a strategy was developed based on input from experts. Leveraging the supportive nature of peer groups, a social group intervention was introduced to enhance adolescents' mental well-being within the CSP. Using a specific research design, the well-being of participants in the intervention group (IG) and comparison group (CG) was measured and compared over time. Statistical analysis confirmed significant improvements in well-being within the intervention group. Additionally, qualitative methods provided valuable insights into the intervention process, aiding in its refinement and showcasing positive outcomes. This research highlights the vital role of social work interventions in supporting vulnerable populations like those in the CSP, ultimately empowering them to lead healthier lives. [ABSTRACT FROM AUTHOR]