Most prior research measures teacher turnover as an annual event, but teachers actually leave their positions throughout the school year. We use data from North Carolina to measure teacher turnover monthly throughout the entire year and conduct an analysis of their persistence to examine the differences in early career teacher turnover. Annually, 6% of early career teachers turn over during the school year. Teachers trained in traditional, university-based programs are most likely to move schools, and alternate entry and out-of-state prepared teachers are more likely to leave teaching, both during and at the end of the school year. We discuss the implications within-year turnover has on creating disruptive learning environments, particularly in underserved schools.