This study unpacks the construct of theorization – the process by which organizational ideas become delocalized and abstracted into theoretical models to support their diffusion across time and space. We adopt an institutional work lens to analyse the key components of theorization in contexts where institutional work is in transition from changing institutions to maintaining them. We build on a longitudinal inductive study of theorization by the Fair Labor Association – a private regulatory initiative that created and then enforced a code of conduct for working conditions in apparel factories. Our study reveals that when institutional work shifts from changing to maintaining an institutional arrangement of corporate social responsibility, there is a key change in how the Fair Labor Association theorizes roles and practices related to this arrangement. We observe that theorization on key practices largely remains intact, whereas the roles of different actors are theorized in a dramatically different manner. Our findings contribute to a better understanding of the work involved in the aftermath of radical change by demonstrating the relative plasticity of roles over the rigidity of practices.