 Participants of syringe exchange programs routinely suffer from untreated or under-treated substance use disorder, a situation that is associated with significant individual and public health costs. These individuals are also routinely embedded within social networks that reinforce continued drug use and related HIV-risk behaviors. The welfare of these individuals and the publics health can be improved by interventions directed toward reducing drug use risks and expanding drug-free support . Previous work by the investigators has demonstrated that an intervention combining an HIV risk reductiontreatment readiness group with behavioral contingencies is highly associated with increased rates of treatment enrollment and re-engagement, and reduced rates of drug use and HIV-injection risks, for up to one year. This protocol extends this work by adding a new component to the HIV risk reductiontreatment readiness group designed to expand social support and facilitate social network change. This intervention requires syringe exchange registrants to attend the group with a drug-free family or friend from their personal network that can provide stable support and encourage harm reduction and treatment seeking. This intervention uses an alteration network change model and posits that repeated exposure to drug-free community support collaterally reduces exposure to network members that support risk behaviors. This model also provides a pathway to modifying existing social networks by facilitating interaction with the personal social networks of drug-free family and friends. The intervention is supported by research showing that substance users report substantial pockets of drug-free family or friends in their social networks. It is also supported by community reinforcement principles that have shown efficacy in treatment samples, but have not been applied to out-of-treatment drug users. The present study has four primary aims. The first is to characterize natural drug-free support in the social networks of syringe exchangers. The second is to develop a Community Supported Risk Reduction group for syringe exchange participants and their community support. This group teaches skills for HIV risk reduction, treatment seeking, and healthy network expansion. The third and fourth aims are to obtain new data on the feasibility and efficacy of this intervention. Primary outcomes include changes in: 1 perceived social support, and 2 HIV risk behaviors. 