It is difficult to name a question more contentious than the question of credentialing for academic librarians. This Element attempts three things. First, to understand how today's US research libraries approach credentialing and hiring. Which assumptions, practices, and arguments for those practices do they make? The study evaluates those practices and rationale both quantitatively-How many people adopt which positions and practices based on which assumptions?-and qualitatively-How compelling are the arguments for their respective positions? The qualitative element feeds into this essay's second effort: to argue, based on evidence offered, that more traditional and restrictive practices hamper and hobble the profession. The third section-derived from follow-up interviews with deans at libraries with liberalized credentialing and hiring practices-chronicles and draws lessons from libraries at the forefront of reform, and then offers advice to libraries examining their own hiring practices. This title is also available as open access on Cambridge Core.