The importance of knowledge workers and expertise continues to accelerate for both organizations and for economies. In addition, experts are increasingly being tasked with contributing to challenges that span their particular domain of expertise. A contemporary example is the U.S. healthcare industry where physicians are increasingly being asked to serve as active partners with healthcare administrators to solve complex challenges such as rising costs, outcome-based reimbursements, and quality of care. Unfortunately, research has shown that individuals who are highly skilled in one domain (e.g., physicians) are rarely are able to transfer that expertise to other domains. This dissertation used qualitative methods to explore an alternate conceptualization of expertise and how this might influence the contribution of experts across domains. The findings from this study suggest that expertise emerges from the dynamic relationships occurring between the social and the material aspects of a situated environment. Therefore, in addition to the knowledge that is resident within an individual, knowing and expertise is also distributed across the various social and material relationships within the specific environment. The main contribution of this research is to expand the standard conceptualization of expertise, which is based on cognitive and socio-cognitive assumptions. This study does not deny the validity of cognitive assumptions about knowledge and expertise but argues that these assumptions do not go far enough in conceptualizing expertise. This research indicates that a sociomaterial conceptualization of expertise allows for a more nuanced understanding into the various constitutive aspects of expertise and in particular a greater sensitivity to the relationship among the aspects.