Task coordination poses significant challenges for globally dispersed teams (GDTs). Although various task coordination mechanisms have been proposed for such teams, there is a lack of systematic examination of the appropriate coordination mechanisms for different teams based on the nature of their task and the context under which they operate. Prior studies on collocated teams suggest matching their levels of task dependence to specific task coordination mechanisms for effective coordination. This research goes beyond the earlier work by also considering additional contextual factors of GDT (i.e., temporal dispersion and time constraints) in deriving their optimal IT-mediated task coordination mechanisms. Adopting the structural contingency theory, we propose optimal IT-mediated task coordination portfolios to fit the different levels of task dependence, temporal dispersion, and perceived time constraint of GDTs. The proposed fit is tested through a survey and profile analysis of 95 globally dispersed software development teams in a large financial organization. We find, as hypothesized, that the extent of fit between the actual IT-mediated task coordination portfolios used by the surveyed teams and their optimal portfolios proposed here is positively related to their task coordination effectiveness that in turn impacts the team's efficiency and effectiveness. The implications for theory and practice are discussed.