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. Efforts to understand why teachers leave and the associated impacts with such turnover are important and ongoing. This paper examines the impact of one model affecting hundreds of schools nationwide and the associated impacts on retention. TAP™: The System for Teacher and Student Advancement was launched in 1999 as a comprehensive educator effectiveness model that offers career advancement and leadership opportunities for educators, as well as an evaluation process that is linked to job-embedded professional development and performance-based compensation. The TAP System focuses on developing human capital at each school through improving teacher instructional practices and student achievement. One additional impact often reported from educators in the field within the TAP System is the influence on teacher retention, which results from the culmination of various support structures for educators. The current study examined teacher retention rates in schools that implemented the TAP System during the 2010-11, 2011-12, and 2012-13 school years for which data were available. Specifically, retention rates were examined across three types of teacher groups, those who: (1) taught continuously at the same TAP school ("TAP school stayers"); (2) transferred from one TAP school to another TAP school ("TAP school movers"); and (3) left TAP schools altogether ("TAP school leavers"). Additionally, the current study examined characteristics of these three categories of teachers. Findings demonstrate the average TAP school retained more teachers than the average non-TAP school. Also, findings show that teachers who taught at TAP schools continuously, regardless of whether it was the same TAP school or a different TAP school, increased in their effectiveness from one school year to the next. Furthermore, the net value of the increased retention is equal to approximately the value of an additional teacher in the school.