Aims: Community outreach services play an important role in infectious disease prevention and engaging drug users not currently in treatment. However, fewer than half of US substance abuse treatment units provide these services and many have little financial incentive to do so. Unit directors generally have latitude about scope of services, including the level of outreach provided to the community. The current study examines how directors' interactions with external stakeholders affect substance abuse treatment units' provision of community outreach services. Methods: Cross-sectional logistic and Poisson regression analyses were conducted on a national sample of US outpatient substance abuse treatment units (N = 547). Results: Findings suggest that the amount of time directors spent with licensing and monitoring associations was associated with provision of a greater number of community outreach services, while time spent with professional and occupational associations was associated with provision of off-site human immunodeficiency virus and hepatitis C testing. Several other director attributes and organizational characteristics also emerged as significant. Conclusions: External stakeholders with whom substance abuse treatment directors interact may influence community outreach through their effects on treatment directors' strategic priorities. Implications for policy and prevention efforts are discussed. (Contains 2 tables.)