Challenges to controlling blood glucose, blood pressure, and cholesterol levels put 16 million U.S. adults at high risk of disabling diabetes complications. Diabetes self-management (DSM) interventions have struggled to deliver relevant, effective, and sustainable support for at-risk adults with diabetes to improve multiple key DSM behaviors, become more activated participants in healthcare, and reduce diabetes complications. One largely untapped resource for this support is patients' family and friends. 75% of adults with diabetes reach out to an unpaid family member or friend (a family supporter) for ongoing help with diabetes management. However, diabetes management interventions to date lack structured and tested approaches to directly engage patients' supportive family members in promoting and sustaining patient activation and improved diabetes management. The objective of this study is to compare the effectiveness of a novel strategy – Family Partners for Health Action (FAM-ACT) – to individual patient- focused diabetes self-management education (DSME) and care management. FAM-ACT directly engages family supporters of at-risk adults with diabetes by providing them the core skills to allow them to effectively support health behavior change, medication adherence, and active engagement with patient's healthcare providers. A fundamental focus of FAM-ACT is providing family with the ability to give autonomy supportive and need-responsive help to patients. Community Health Workers (CHWs) will deliver FAM-ACT to low-income patients and their family supporters, plus take the novel step of helping family supporters integrate their efforts with those of patients' primary care teams. The specific aims of this study are to 1) Compare the effect of FAM-ACT on patients' diabetes health outcomes to standard, individually-focused, CHW-led DSME and Care Management (DSME+CM), 2) Compare the effect of FAM-ACT on patient health behaviors and perceived support to standard, individually-focused DSME+CM, and 3) Examine whether health and health behavior gains made in FAM-ACT are better sustained after the intervention period than those made in DSME+CM. 240 patient + family member pairs will be randomized to FAM-ACT or DSME+CM for 12 months. Main diabetes health outcomes will include change from baseline to 12 months in UKPDS 5-Year cardiac risk score, HbA1c, and systolic blood pressure. Main patient behavioral outcomes will include diabetes self-management behaviors, and perceived social support and autonomy supportiveness from family. Sustainability will be assessed at 18 months, after a period of 6 months without CHW intervention. We expect this study to produce an innovative, evidence-based protocol and tool set that leverages family support to help patients optimize and sustain management of multiple diabetes complication risk factors over time. This project is innovative because it provides family supporters with underlying support, communication, and health...