Background/Context: The No Child Left Behind (NCLB) Act was a performance-based accountability policy designed to motivate educators and administrators to change their behaviors and improve school and student outcomes. The simple logic behind this accountability policy was that they would change their behaviors to avoid sanctions. Many studies have investigated the impact of NCLB on students and teachers; however, little research has examined its impact on school principals even though they were a prime target of NCLB. Purpose/Objective: This study fills the gap in the literature and investigates the impact of NCLB sanctions on principal turnover. It answers whether NCLB's informal and formal sanctions influenced principal turnover behaviors and whether the influence was moderated by principal and school characteristics. It also examines patterns in principal transfers and position changes. Research Design: This study uses longitudinal administrative data and detailed school-level assessment data obtained from Missouri Department of Elementary and Secondary Education from 2001-02 to 2009-10. It constructs a distance variable to the adequate yearly progress threshold and uses it as a key matching variable in propensity score matching to identify comparable schools not facing NCLB sanctions. Post-matching logistic regression models identify the impact of NCLB sanctions. Findings/Results: Although I find no evidence that informal sanction affected principal turnover, the impact is significantly moderated by principals' job experience, Title I school status, and the percent of non-White students. The first-year NCLB sanction does not appear to have affected principal turnover. However, this finding needs to be interpreted with caution because of the way the NCLB sanction system is structured and the small sample sizes. A descriptive analysis of the relationship between the second-year NCLB sanction and beyond, and principal turnover suggests that principals tend to leave their schools when they face NCLB sanctions. Finally, I find that principals transfer away from Title I schools, transfer to schools with a smaller number of high-needs students, and take positions at district central offices, regardless of whether they face NCLB sanctions. Collectively, NCLB sanctions appear to have impacted principal turnover. Conclusions/Recommendations: The results from this study have policy implications. They suggest that policy makers should provide professional support and adequate resources for principals, especially inexperienced principals, who work at low-performing schools and face sanctions. Moreover, policy makers should develop and embed a policy in new accountability systems that addresses inequity in the distribution of principal quality.