Municipal efforts to promote sustainable development are geographically and temporally uneven across the country. Although cross-sectional research informs our understanding of contextual and institutional factors that drive municipal commitments to sustainability, the agency of policy change at the individual level is not well documented. This article examines the context of executive turnover, in particular, city mayors and managers. Specifically, the author hypothesizes a disruptive or adaptive effect of executive turnover would depend on who leaves and who succeeds in the office. Employing the two- wave ICMA sustainability survey of more than 400 cities, the hypotheses are tested using longitudinal analysis. The results indicate managerial turnover in general is associated with reduced sustainability policy adoptions while only the departure of mayors assertively committing to sustainability would lead to the same negative effect. More sustainability policy adoptions would be conditioned on hiring outsider managers, early in their tenure.