Chronic diseases such as type 2 diabetes mellitus (T2DM) are increasingly common and costly, imparting debilitating economic and health effects. This case presents the use of an individualized behavioral intervention for diabetes management in a 61-year-old African American woman with T2DM. The intervention was delivered over five home-based treatment sessions and two follow-up probes that focused on nutrition. At the end of treatment, the participant exhibited improved nutrition and dietary habits (i.e., increased intake of fruits and vegetables; eating more, smaller meals throughout the day), which maintained through follow-up. In addition, she demonstrated generalization of treatment effects, as evidenced by the application of treatment strategies to other areas of her health (i.e., exercise and blood glucose testing). This case study highlights how psychological treatment emphasizing behavioral techniques can be effectively applied to manage medical conditions and mitigate future complications and comorbidities.