In this paper, we examine the evolution of the institutional and intellectual structures of the IS field. We argue that, though the field’s institutional structures—academic programs, journals, conferences, and professional associations—have developed admirably, the state of the field’s intellectual structure is less clear. We employ a co-citation lens to analyze the development and evolution of subfields across three periods. We rely on Culnan’s (1987) second co-citation study as a point of departure for our analysis. We then extend her work through two additional studies that individually assess the state of subfield development at distinct periods during the field’s history. Over the three periods, we note that the field has experienced change in subfield diversity and cohesion. Culnan’s study exhibits low levels of cohesion and diversity among topics. Our first study shows continued isolation but growth in subfield diversity. This period is indicative of a fragmented adhocracy. Our second study suggests increasing levels of integration despite only a slight reduction in subfield diversity. While we largely only describe the field’s evolution, any assessment of whether this evolution represents a positive or negative trajectory for the field will be subject to interpretation and debate.