A key goal of drug abuse treatment providers is getting their clients to engage and participate in therapeutic activities as a first step toward deriving longer-term benefits. Much research had focused on personal characteristics that relate to client engagement; program characteristics have received less attention. This study explored client and program differences in engagement ratings using data from a nationwide set of 94 outpatient drug-free treatment programs in a hierarchical linear model analysis. The results show that elements of program context, including structural features (e.g., smaller size and Joint Commission on the Accreditation of Healthcare Organizations/Commission on Accreditation of Rehabilitation Facilities accreditation) and staff's perceptions of personal efficacy, organizational climate, and communal workplace practices, relate to better overall client engagement. These findings add further evidence that treatment providers should also address the workplace environment for staff as part of quality improvement efforts.