Contemporary public management research has focused heavily on the consequences of public service motivation (PSM). However, only a handful of studies have been conducted to develop context-indifferent measurement scales that reflect the nature of this central concept, which ranges along a continuum from controlled to autonomous motivation. This study proposes a new PSM model grounded in self-determination theory (SDT) and empirically validates two behavioral elements for the SDT-based PSM using data from Guangdong Province of China. Specifically, it is found that (1) the withdrawal behavior of public employees is positively influenced by their external PSM, negatively associated with identified and introjected PSM, and independent of intrinsic and integrated PSM; (2) there are positive relationships between introjected-, intrinsic-, identified-PSM, and taking-charge behavior; and (3) integrated and external PSM do not show significant outcome effects. Acknowledging that different motivational dimensions underlying the SDT-based PSM vary in their importance to the stimulation of withdrawal and taking-charge behaviors, the paper concludes with a future agenda for SDT- and PSM-related research that can be furthered in a manner that enriches theory or illuminates practice.