Abstract: The centrality of the CEO is reflected in the empirical literature linking CEO turnover to poor firm performance. However, less is known about the institutional and personal correlates of CEO turnover. In this study, we find two CEO characteristics interact with turnover: tenure and ownership. We interpret our results as indicating that CEOs of S&P 500 firms divide into two groups with different tenure patterns – “owners” (who have large personal shareholdings) and “managers” (who have smaller holdings). The tenure of manager-CEOs (as opposed to owner-CEOs) exhibits a term structure loosely similar to the one produced by the tenure process at academic institutions. Turnover significantly depends on firm performance during a CEO’s first four years on the job. In particular, external turnover by sale of the firm peaks a year 4 during a CEO tenure. By contrast, external turnover peaks at years 5 – 6, and plateaus at relatively high levels until year 9 of tenure. These term effects are strongest for relatively young CEOs. We also find that forced exit, retirement, and deals covary rather than substitute for one another as modes of CEO turnover. However, forced exits and deals both relate to poor performance by the firm on different metrics. Our evidence suggests that most internal turnover, particularly after a CEO’s first five years, is unrelated to firm performance.