Background: The rate of hyperglycemia in adolescents with type 1 diabetes mellitus (T1DM) who use insulin pump therapy is three times higher than in those using multi-dose insulin. Current literature suggests that the causes of the increased hyperglycemia rate are insufficient patient education, missed insulin boluses for meals/snacks, pump malfunction, psychological effects, pubertal physiological changes, and adolescents’ risky behavior. Purpose: This quality improvement project aimed to reduce the rate of hyperglycemia and diabetic ketoacidosis in adolescents age 12–18 with T1DM on insulin pump therapy through evidence-based interventions. Methods: Participants were recruited from four western Massachusetts public schools. Innovative diabetes self-care education and peer group support were used. Educational sessions and peer group knowledge discussions occurred once a week from January 10, 2017 to March 14, 2017. Results: Findings indicated that the evidence-based educational program was effective in improving self-care skills in adolescents with T1DM on the insulin pump. The outcome showed that when knowledge of self-care management improved, the complications of TIDM such as hyperglycemia and DKA decreased. Conclusion: A multifactorial approach integrated with psychosocial support will promote self-care activities and reduce the short- and long-term complications of T1DM in adolescents.