Substance abuse is a complex problem with numerous related issues that must be addressed in treatment, making it important to consider factors that contribute to the likelihood that service integration efforts will be made by agencies. This research project explores characteristics impacting level of service system integration. Resource dependency theory and Konrad''s model are extended by Integral theory and guide the study.This study uses a cross-sectional survey, with program director questionnaires collected from an availability sample of 153 substance abuse service delivery units in Maryland. Multiple regression analysis was used to determine the direct effects of organizational and target population variables on service system integration and service diversity. The number of services provided by substance abuse treatment agencies in the State of Maryland is low. Leadership and membership need to be taken into consideration when implementing and researching efforts at service system integration.