Psychologists bring great value to health care systems, but our ethnocentrism regarding the medical community often limits our effectiveness as agents of change. Based on experience in developing pain management services within the Department of Veterans Affairs health care system, we discuss cultural issues as central to effective systems change and provide specific recommendations for psychologists aspiring to change organized health care systems, such as the Department of Veterans Affairs. Consideration is given to the misfit of the biomedical model to chronic pain, “physics envy” affecting the authority accorded psychology, and societal stigmatization of psychopathology. A process-based definition of cultural competence is recommended as improving on psychology’s intrinsic group-based notion of culture in engaging the medical community. The systems thinking literature is sampled in summarizing practical recommendations that include identifying features of local medical culture and power dynamics between psychology and medicine that can be modified by engaging stakeholders in an interpersonally effective manner. (PsycINFO Database Record (c) 2010 APA, all rights reserved)