Background: Managing and treating insomnia in patients with diabetes mellitus requires the examination of current literature of evidence-based research implementing pharmacological and non-pharmacological interventions. This QI project focused on the implementation of Cognitive Behavioral Therapy for Insomnia (CBT-I). Purpose: The purpose of this project was to implement CBT-I in adult patients with diabetes mellitus (DM) and examined whether it alleviated their insomnia symptoms using the Pittsburg Sleep Quality Index (PSQI) tool. Methods: The study used a one-group pre-test and post-test intervention design; the intervention is a free application, “CBT-i Coach”. 20 participants were invited to participate from an Endocrinology office who were over the age 18, and who fit additional criteria. Participants used the self-study application at home for 4 weeks with scheduled follow-up emails and calls. The Pittsburg Sleep Quality Index (PSQI) was used to assess the baseline and post-intervention sleep quality. Results: 40% of participants (n=8) completed the intervention. The pre-PSQI mean score was 9.9 (SD=3.4) and the post-PSQI mean score was 6.6 (SD=5.1), demonstrating improvement in insomnia sleep quality post intervention implementation. Discussion: The study findings demonstrated that CBT-i Coach improved insomnia after participants used it at home for 4 weeks. Nursing Implication: CBT-i Coach is an effective intervention for nurses and providers to teach to their patients and implement for adults with Diabetes Mellitus. Due to the easy-to-use and free digital format, healthcare providers would be inclined to recommend the use of CBT-i Coach in patients complaining of insomnia symptoms. Keywords: Diabetes, insomnia, sleep disturbance and diabetes, CBT for diabetes, treatment for insomnia in diabetes, nonpharmacological interventions for sleep in diabetes, cognitive behavioral therapy, and sleep disorders.