Agile coaches play a key role in supporting software teams and organisations during agile transformations, yet little is known about how they understand and design for the continuation of agility after their involvement ends. This study fills that research gap by examining how agile coaches perceive post-exit outcomes and describing the strategies they use to support endurance beyond their engagement. Drawing on sixteen semi-structured interviews with professional agile coaches across multiple organisations, we identify six interconnected themes that capture coaches’ accounts of embedding routines, transferring ownership, and aligning agile values with organisational contexts. We synthesise these themes into the concept of sustainment work, referring to the professional and organisational efforts that coaches describe undertaking to support the continuation of agile ways of working beyond their direct involvement. This synthesis is represented in an empirically derived model comprising three interrelated domains: Embedding Practices, Enabling Ownership, and Aligning Culture. The model reflects how coaches conceptualise the relationship between their interventions, anticipated post-exit trajectories, and the endurance of agile practices, rather than providing evidence of long-term organisational outcomes. The paper contributes theoretically grounded insights into how agility is understood and approached by highlighting coaches’ perceptions and intended sustainment strategies, as an ongoing organisational concern rather than a time-bound coaching intervention.