We evaluated the effectiveness of a diabetes life coach program designed to address the concerns of limited coordination and collaboration of care for chronically ill patients in the physician office. The program emphasized lipid, blood pressure, and glycemic control, using personal coaching, group classes, reminders, and customized feedback. The target population was all health plan members over age 18 with type 1 or 2 diabetes mellitus in 6 primary care practice sites in the Hampton Roads area of Virginia. Primary outcomes were 1 Health Plan Employer Data and Information Set measure (A1c poor control of >9% or no test), 3 American Diabetes Association (ADA) measures (A1c <7%, blood pressure of <130/80 mmHg, low-density lipoprotein cholesterol [LDL-C] of <100 mg/dL), 1 pharmacy measure (percentage of patients filling at least 1 insulin prescription), and 2 self-reported behavioral measures (percentage adherent to a meal plan and percentage adherent to an activity plan). We assessed overall program outcomes and differences between individual physician practices and evaluated outcomes separately for engaged compared with non-engaged program participants. Outcomes for 1117 participants were evaluated. Statistically significant improvement at P < 0.05 was noted in all 7 targeted measures compared with baseline. Participants who were engaged in the life coach program were 40% less likely to experience poor control of their A1c, 50% more likely to meet the ADA A1c goal of < 7%, 11% more likely to meet their blood pressure goal of <130/80 mmHg, and 7% more likely to meet their LDL-C goal of <100 mg/dL compared with those not engaged. Patients who became engaged in the program performed significantly better in the key diabetes indicators that ultimately lead to reductions in the complications of the disease over time. Our study contributes to the evidence that clinical multidisciplinary, collaborative models of care can influence and improve the management of diabetes.