Organizations increasingly rely on flexible work arrangements, such as innovation task forces and quickly assemble members with diverse expertise needed to create innovative solutions to problems. The literature has produced mixed findings on the relationship between member familiarity and innovation, which we suggest may be explained by two forms of coordination: expertise and dialogic. We hypothesize and find that dialogic coordination produces more innovative outcomes for unfamiliar task forces, while expertise coordination produces more innovative outcomes for familiar task forces. Furthermore, dialogic coordination in unfamiliar task forces is associated with greater innovative outcomes than expertise coordination in familiar task forces. Our results also highlight the importance of temporal dynamics of dialogic coordination in task force work. Hypotheses were tested through a longitudinal analysis of survey data with external ratings of the innovation outcome from 179 individuals in 32 innovation task forces from 13 U.S.-based firms in the top 10% of the world's growth industries during a period of recession. The findings contribute to an understanding of coordination in contemporary turbulent work environments.