Design rework is a core phenomenon in new product development (NPD). Yet carrying out design rework presupposes recognizing the need for it. I characterize the types of interpersonal knowledge transfer that help developers realize the need for design rework in NPD. As predicted by the NPD literature, I find that individuals who interact frequently with colleagues to address their task interdependences are more likely to realize the need for rework. I also learn that interacting with colleagues who have different expertise in process-related knowledge (as opposed to product-related knowledge) facilitates realizing the need for rework. However, to develop a deeper understanding of how individuals recognize the need for rework when interacting with others, we must expand our views beyond task interdependence and expertise-related factors. In particular, organizational variables—both formal and informal—play a significant role. With respect to formal hierarchical structures, actors of superior rank are less likely to realize the need for rework regardless of whether or not their interacting partner is of superior rank; however, actors of superior rank are more likely to trigger realizing the need for rework when interacting with partners of subordinate rank. By examining an organization's informal structure, I discover that the social “embeddedness” of developers (i.e., the energy and attention invested in a dyadic relationship) significantly influences their propensity to realize the need for rework. Several hypotheses are tested in a sociometric study conducted within the development department of a software company, and I discuss the implications for behavioral operations in NPD.