The present study assessed the potential of a health behavior model used to explain adherence to treatment for chronic illnesses, the Integrative Behavioral Prediction Model (IBPM), to better understand therapy engagement (e.g., low participation) for child therapy in community-based service settings. Qualitative interview methods were used to assess the fit of the IBPM to therapy engagement. Caregivers of children (n = 17) who had successfully completed therapy, were at risk of dropping out, or terminated prematurely at a community mental health clinic were interviewed. Clinic therapists and administrative staff were also interviewed (n = 8). From the perspective of caregivers, therapists, and administrative staff, most IBPM elements—cognitions, intentions, and environmental/contextual factors—appear to be relevant to therapy engagement. Other factors, such as personal and psychological barriers (e.g., poor fit with therapist), not found in the IBPM also may influence therapy engagement. It appears that the core elements of the IBPM may translate to child therapy, though future research is needed to evaluate the generalizability of the study findings. Thus, health behavior models (e.g., IBPM) may improve our understanding of factors contributing to poor therapy engagement for children receiving psychosocial therapy in community-based service settings.