This study assessed secondary outcomes of Connecting, a low-cost, self-directed, family-based prevention program for families with youth placed in their care by state child welfare agencies. Families caring for youth aged 11 to 15 years within Washington State were recruited and randomly assigned into either the Connecting program (n = 110) or a treatment-as-usual control condition (n = 110). The program included a 10-week sequence of self-directed family activities and DVDs with video clips. Survey data were collected from caregivers and youth at baseline, immediately post-intervention, and at 12 and 24 months post-intervention; placement data was collected from the child welfare department as well. Intention-to-treat analyses focused on 5 classes of secondary outcomes at 24 months post-intervention: caregiver-youth bonding, family climate, youth risk behavior attitudes, youth mental health, and placement stability. There were no intervention effects in the full sample. In subgroup analyses, among older youth (ages 16–17) but not younger youth (ages 13–15), the Connecting condition (vs. controls) yielded more frequent caregiver-reported bonding communication, bonding activities, warmth, and positive interactions, as well as less favorable youth attitudes towards early initiation of sexual behavior and substance use, and fewer youth self-injurious thoughts. Consistent with the social development model, the divergent outcomes between younger and older youth suggests Connecting’s driving mechanisms involve social processes that undergo critical shifts between early and mid-adolescence. Overall, the Connecting program showed promise in older youth for long-term promotion of caregiver-youth bonding, healthy behaviors, and mental health, but did not demonstrate long-term efficacy in facilitating stable or permanent placement of youth in care.