In this paper we examine the mobility of early-career teachers of varying quality, measured using value-added estimates of teacher performance. Unlike previous studies that have examined these issues, we focus on the variation in these effects across the effectiveness distribution. We find that, on average, more effective teachers tend to stay in their initial schools and in the teaching profession. But there also appears to be heterogeneity in mobility behavior across the performance distribution, and evidence that teacher mobility is affected by student demographics and achievement levels. (Contains 6 tables and 53 footnotes.)