This paper reconnects to the intellectual climate from which the formulation of the boundaryless career perspective emerged in the 1990s. Based on 17 years of cumulative research, we develop the case for extending beyond a primary focus on boundaryless careers as forms (e.g., contractor or global itinerant). We argue that opportunities for further theory development in this field can emerge from addressing some of its fundamental debates, and developing a more systematic understanding of career agency. In this respect, we see promise in research that develops our understanding of interdependent notions of career agency. To guide further research, the paper identifies six features of agency related to individual variation, social referencing, practice, outcomes, contexts, and learning. We propose that each of these illustrates contrasting assumptions about independent and interdependent views of the career. We discuss how the other papers of this special issue inform our understanding of these six features and identify promising directions for further research. We conclude that the future relevance of the boundaryless career perspective will depend on its openness to the challenges of careers within the inherently dynamic, uncertain, and complex arena of an interdependent global society. Copyright © 2010 John Wiley & Sons, Ltd.