Adolescents with substance use disorders (SUD) are at substantial risk for contracting HIV/STIs compared to their counterparts without SUD, yet few HIV/STI sexual risk reduction interventions have been developed to meet their unique needs, and none use a family-based intervention approach, which the literature recommends as the focus for intervention for youth. Current state policies neither require providers in clinics delivering substance use treatment to offer HIV/STI sexual risk reduction nor offer providers tools or training for HIV/STI prevention. There is clear public health need to develop innovative methods of service delivery and effective strategies of HIV/STI sexual risk reduction that address multiple contexts of risk (i.e. family) for this high risk population. The current proposal addresses this need by developing a provider-delivered HIV sexual risk reduction intervention to be implemented in outpatient SUD treatment that: 1) builds the clinics' capacity to help families under their care to more comfortably address the adolescent's sexuality; 2) promotes youth's safer sex practices; and 3) reduces HIV/STI sexual risk behaviors among adolescents with SUD in care.