Research at the federal level in Canada suggests that women MPs are leaving office earlier than their male colleagues, and that this is explained almost entirely by women disproportionately choosing not to seek re-election (Wallace and Goodyear-Grant forthcoming). These data signal cause for concern regarding women’s representation and progressive ambition. In this new paper, we first establish the descriptive patterns, examining whether the gender longevity gap exists across Canada’s 13 provincial and territorial governments, and key goals here will be to establish whether the average pattern is different than the federal pattern, as well as what the variations are across sub-national units. Existing work has established that these sub-national units vary considerably and consistently in women’s descriptive representation (Trimble and Arscott 2008; Trimble, Tremblay, and Arscott 2013; de Geus et al. 2021), and this paper asks if the same is true and why for career advancement and tenure in office. Then, we will leverage comparative analysis of exits and retention patterns to ask whether we can find evidence suggesting causal mechanisms for cross-unit variation in the gender longevity gap with a focus on institutions and other opportunity structures and provincial/regional political cultures. Research on political exits remains crucial for understanding women’s descriptive and substantive representation, and closer attention to the subnational level can provide an important context for comparative analyses.