The Veterans Health Administration (VHA) is the largest integrated health care system in the United States, serving more than 8 million veterans. VHA is currently undergoing extensive changes to its health care delivery model, moving toward the full implementation of the patient-centered medical home. Mental health providers, including psychologists working in primary care, are playing key roles in this transformation to interprofessional teams and systems—as clinicians, researchers, program evaluators, and educators. Moreover, VHA mental health staff serves critical leadership functions supporting primary care in the broad transformation that is required to implement the medical home. In this article, we review the implementation of mental health integration into this new model of care.