The overriding finding from the formative evaluation was the difficulty in fully implementing mandatory referral to mental health treatment across the collaborating agencies, the courts, mental health clinics, and batterer programs. The inconsistencies in screening and referral emerged and undercut the implementation of the supplemental mental health evaluation and treatment. In addition, the different missions of each of the agencies posed different priorities, orientations, and emphases. The formative evaluation proved to be of vital importance in interpreting and discussing the results of any outcome evaluation, in this case, the effectiveness of supplemental mental health treatment in improving batterer program outcomes. A screening and referral system for batterer program participants in Pittsburgh, PA was established as a demonstration project to add additional staff at the batterer program and pay for treatment costs not covered by insurance. The formative evaluation of this screening and referral system drew on direct observation of the agency procedures, participation in training and supervision meetings, debriefing interviews with administrators, and informal comments from program staff and participants. Figure, table, and references