Teachers working in urban schools in the United States are among those most at-risk for leaving the profession due to poor working conditions and lack of collegial relationships with school leaders and peers, among other factors. Use of professional development tools, such as the School Improvement Engine (SIE), may improve teacher retention and school organizational health; however, little research exists on the use of the SIE in charter schools. The purpose of this case study was to investigate New York City (NYC) school data on teacher retention and student achievement, how NYC charter school leaders participating in the program implemented the SIE, and how teachers and administrators perceived the impact of the implementation on their individual growth and desire to stay in their positions. Peter Senge's organizational learning theory was used to examine how SIE tools may promote a healthy organization in 5 areas (systems thinking, personal mastery, mental models, building shared vision, and team learning). Teacher retention and student achievement archived data for NYC schools were descriptively analyzed. Individual interviews were conducted with a purposeful sample of 10 teachers and 4 school leaders from NYC charter schools implementing the SIE. Interview data were analyzed using open coding to identify key themes. Results indicated that SIE schools outperformed other NYC schools (charter and public) in English Language Arts (ELA), math, and teacher retention. Participants stated that tools like peer review helped them to become more effective in their teaching. Positive social change impacts include providing data that support the use of the SIE to improve teacher effectiveness, teacher retention, and the overall school organizational health.