Background: Resident well-being leads to better patient care practices, but a systematic approach is needed to achieve the wellness agenda. The Theory of Change was used for developing an interventional model for wellness in our study, after identifying the causes of burnout and attrition in a pediatric residency program. Methods: This was a quality improvement project where residents were asked about their main stressors in an anonymous open-ended feedback form. Workload (n=63, 37.5%) was identified as the main source of dissatisfaction. A database of 43 residents who quit in the past ten years was examined to find 40.0% of residents left after the first year of training and the main cause was marriage and/or family concerns (28.9%). Then literature was reviewed to build a wellness intervention's framework. Finally, the Theory of Change was applied focusing on restructuring the residency core, accountability and communication, and stress management. The final theory of the change model included the assumptions that the program needed restructuring because of high attrition, low first pass exam rate, and decreased patient satisfaction. The goal was to increase resident wellness and performance, while keeping patient care at the core. Results: The short-term outcomes were drop in attrition rate from an average of 8.67% to 1.75%, decrease in FCPS exam attempt from 3.3 to almost 1, and an increase in patient satisfaction. Conclusion: Using the Theory of Change, it was possible to address residents’ concerns, increase their retention and improve patient satisfaction by reconstructing the wellness program.