This study will evaluate an intervention to help Veterans with diabetes get the most benefit from VA care and be successful at managing diabetes. The intervention aims to increase the capacity of VA primary care clinics to support the family members and friends who help Veterans with diabetes engage in their health care. This intervention is designed to be patient and family-centered - it gives Veterans and their supporters skills and tools to take action in managing diabetes, and to work effectively with patients' VA primary care doctors and nurses. If successful, the study will establish a new approach for involving patients' supporters in VA care, in ways that could avert devastating consequences of uncontrolled diabetes. Similar methods could then be used by the VA to better support Veterans' family caregivers, and to improve health management, for Veterans with other high-risk conditions.