We examine turnover reasons for dysfunctional (i.e., high-performing or high-competency) leavers versus functional (i.e., low-performing or low-competency) leavers. In a United States retail bank, high performers reported wanting better advancement or development opportunities as their top turnover reason, whereas low performers mentioned wanting different job tasks, job insecurity, work stress, problems with coworkers, and generic problems with management more frequently than high performers. In an Indian IT consultancy firm, job performance and competency level were positively related to reporting problems with leadership/upper management, whereas performance was negatively related to reporting a specific alternative job offer. Through these studies, we develop a novel turnover reason measure for scholars and practitioners that assesses reason importance, enables the vital accumulation of data across studies, and increases diagnostic potential in exit or stay interviews/surveys. Finally, we offer directions for building theory and improving the management of high-performer turnover.