Flexperts are a particular category of experts who are in the possession of in‐depth domain‐specific knowledge and skills combined with the ability to develop and materialize new areas of expertise, that is, expertise renewal. This ability enables them to decisively respond to new expertise demands that arise as a result of changes in their expertise territories. Thus far, there is a limited understanding of how flexperts develop new areas of expertise in a complex, professional setting, and how they accomplish to materialize this new expertise for multiple stakeholders, both inside and outside organizations. In this qualitative interview study, we aim to increase our understanding of the processes by which flexperts accomplish the renewal of their expertise. Ten Dutch flexperts, known for their high level of expert performance and ability to renew their expertise, and from a variety of disciplines, were interviewed. Based on the findings of our study, we have developed a model that summarizes their expertise renewal processes. This Model of Expertise Renewal extends process models on expertise redevelopment and adaptive expertise, and provides directions for future research on how the ability of expertise renewal contributes to the career sustainability of experts. Furthermore, it provides experts, Human Resource Development (HRD) practitioners, and line managers with a framework for creating learning paths and interventions for renewing expertise in case expertise territories are about to change.