We pose a structural model of the managerial labor market with general and firm-specific human capital accumulation, managerial bargaining power, and imperfect labor market competition. Empirically, firm-specific skill drives wage growth and variability over careers; it also restricts mobility and helps explain the low rate of external CEO hiring. We decouple bargaining power from labor market competition in managerial rent extraction, with competition accounting for a substantial share, especially for poached CEOs. Firm-specific skill accumulation increases match productivity between firms and managers, shaping the dynamics of rent extraction by raising rent growth over tenure while dampening it over experience.