This article examines variables that predicted outpatient treatment entry within 6 months of residential detoxification. Patient data were collected from 632 injection drug users enrolled in a randomized trial conducted at eight detoxification programs within the National Drug Abuse Treatment Clinical Trials Network (CTN) with follow-up assessments conducted at 2, 8, 16, and 24 weeks. Detoxification program characteristics were collected during this study and from a survey of CTN treatment organizations. Survival analysis found that estimated proportions of reported outpatient treatment entry varied across sites from .06 to .72. A model-building approach determined variables significantly associated with outpatient treatment entry. The best predictive model contained five program-level variables: accreditation, fewer beds, longer stays, shorter distance between detoxification and outpatient unit, and larger city population. Results suggest the importance of detoxification program characteristics in facilitating further treatment and the need for systems modifications to improve continuity of care.