Using a human capital theory framework, this study examines the impact of educational mismatches on earnings and occupational mobility. Occupational mobility theory suggests that overeducated workers observe greater upward occupational mobility and undereducated workers observe lower upward occupational mobility. By extension, this leads to relatively high earnings growth for overeducated workers and relatively low earnings growth for undereducated workers. Moreover, overeducated workers are probably transient relative to their undereducated counterparts, so employers have few incentives to invest in their human capital. Accordingly, their experience will be rewarded at lower rates. These results may also occur if the unused human capital of overeducated workers depreciates with nonuse. The data verify these predictions. Insights on the link between experience and educational mismatches are also examined.