Each year teacher turnover presents instructional, organizational and financial burdens that impact students, teachers, schools and communities. High levels of teacher turnover drain valuable resources and make it difficult to build a high-performing, stable teaching faculty. This is particularly true in high-need schools where teacher attrition levels are higher than average. This paper examines the impact of the TAP System on retaining teachers, and ultimately, on retaining effective teachers. Results of the study, which examines over 12,000 teachers across ten states, show that TAP System schools retain approximately 14% more teachers than comparable non-TAP schools. Further, teachers in the TAP System schools significantly increased their effectiveness from one school year to the next. This paper demonstrates the power of the TAP System to retain effective teachers and discusses the associated benefits to retaining more effective teachers.