Increasingly mobile careers mean that today’s hiring firms encounter external prospective employees who hold professional affiliations with more organizations (e.g., former employers) and groups (e.g., project teams) than ever before. This trend invites attention to a collection of hiring practices in which a firm leverages prospective hires’ professional affiliations to increase the firm’s access to and facilitate the efficient selection of individuals in a particular labor market talent segment––hereafter, hiring by professional affiliation (HBPA). We review research on six HBPA practices: acqui-hiring, boomerang hiring, competitor poaching, formative affiliation hiring, liftouts, and supply chain hiring. Using Podolny’s pipes and prisms metaphor, we show that research on HBPA has emphasized hiring organizations’ efforts to (a) leverage prospective hires’ focal professional affiliations as prisms to facilitate matching between the organization and new hires, and (b) leverage new hires’ focal affiliations as pipes to access resources otherwise difficult to acquire. Transcending the focus of extant research on individual HBPA practices, we then develop propositions elaborating the conditions under which HBPA is likely to yield varied consequences for firms’ workforce composition and organizational capabilities––ranging from replicating the status quo to increasing workforce diversity and organizational capacity for innovation and change.