In the wake of the discourse on Digital Transformation, the phenomenon of socio-technical inertia has caught the attention of Information Systems researchers. As a latently present theme in both practical and theoretical discourse, it is recurrently referred to as an explanation for the large share of transformation initiatives going awry. Despite its prevalence, socio-technical inertia remains an undertheorized, elusive, and ambiguous concept. Based on a structured review, we propose a sensitizing conceptualization of socio-technical inertia as a relative force and a mutual constituent of transformation. From a mechanism-based explanation, we derive an analytical multilevel perspective on the conceptualization and explore this lens in a case study. The case company has transformed its socio-technical macro regime through multiple major alterations of its workplace information technology infrastructure. We illustrate how such alterations in local fields of work contingently evoke inertia. Thereby, inertia is manifested not just as resistance to shifts in the socio-technical regime but also by mechanisms of perfunctory change, through which it undermines transformational efforts. Our findings imply the need for a new angle on inertia in future research and support an alternative managerial conception of transformation to the one currently dominating the discourse.