Changes in funding, clientele, and treatment practices of public and privately owned substance abuse treatment programs, compelled in part by increased cost containment pressures, have prompted researchers' investigations of the implications of organizational form for treatment programs. These studies primarily probe associations between ownership status, patient characteristics, and services delivered and do not empirically link organizational form or structure to treatment outcomes. Data from the National Treatment Improvement Evaluation Study (NTIES) were used to study the relationship of ownership and other dimensions of “publicness” identified in the public management literature to patient outcomes, controlling for patient characteristics, treatment experiences, and other program characteristics. A few effects of organizational form and structure on substance abuse treatment outcomes are statistically significant (primarily improved social functioning), although the specific contributions of measures of ownership and publicness to explaining program-level variation are generally small. © 2004 by the Association for Public Policy Analysis and Management.