The Veterans Health Administration (VHA) in the U.S. Department of Veterans Affairs (VA) provides mental health and medical treatment for veterans. The VA Office of Policy and Planning contracted with Altarum Institute and the RAND–University of Pittsburgh Health Institute (RUPHI) to conduct an independent study to evaluate its mental health services. Critical to this evaluation was the development of a comprehensive set of mental health performance indicators based upon available VHA administrative and medical record data. This report presents the technical specifications for the performance indicators developed during the study. The evaluation team applied the Institute of Medicine quality of care framework in the identification of performance measures and drew upon existing performance indicators developed for the mental health population, clinical practice guidelines for mental health diagnoses, and the clinical expertise of team members and advisors. The VHA has directly contributed to the development of the quality indicators described in this technical manual through an advisory group composed of representatives from the VHA Patient Care Services, the VHA Office of Mental Health, field practitioners, and contractors. The contents of this report will be of interest to policymakers, health care organizations, and clinical practitioners who are engaged in activities related to the improvement of mental healthcare quality.