As rankings have become increasingly institutionalized in higher education, so too have the strategic responses adopted by universities to address them. A key component of these responses is the development of new expertise, embodied in personnel and organizational units, dedicated to managing quantitative assessments. We draw on a qualitative study of rankings management departments in South Korea to investigate the effects of these new actors in the field of higher education. We find that the rise of new expertise in rankings has reshaped key interdependencies both within universities and between universities and external constituents. This transformation has helped rankings management departments effectively challenge existing work routines and introduce new organizational practices. More generally, this work builds on theories of micro-level institutional change, identifying new mechanisms through which local actors effect lasting alterations in the organizational environment.