Job mobility has recently been promoted in the public sector across countries as a way to diversify and enhance staff knowledge, experience, and skills. This paper evaluates its effect through the experience of Taiwan that boasts a highly flexible government internal labor market. The market allows for relatively open upward and lateral job mobility. This paper shows that Taiwan has an employee-friendly government internal labor market that helps retain talent for the state. However, the cost of a deregulated crossagency manpower movement is a serious internal brain drain. By comparing the behavior and attitude between statutory civil servants and government contract employees in Taiwan, this paper posits that the availability of a flexible internal labor market inevitably causes a “footloose effect” on turnover decision.