We propose a framework of constrained agency grounded in the actors’ resources and motivations within their structurally constrained context. Structural positions influence the resources available to actors and color the motivations that shape their actions. Resources equip actors to exert agency, while motivations propel them to do so. We derive a typology of network actions and illustrate how the form of constrained agency through which a particular network action is taken can affect actors’ ensuing structural positions and the nature of the constraints they subsequently face. Our conceptualization of constrained agency identifies new sources of endogenous change in network structure.