This article investigated whether and how the negative outcomes of perceived prior experienced coworker interpersonal mistreatment persist even when the targeted individual quits and joins a new organization. Drawing from the stressor–strain model, the perseverative cognition model of stress, and social exchange theory, we proposed that individuals’ rumination about perceived prior experienced coworker interpersonal mistreatment following turnover and up to entry into the new organization negatively impacts their mental health and ability to socially integrate into the new organization. We further posit that the negative relationship between individuals’ reduced mental health and their social integration will be weaker for newcomer employees with high propensity to trust (PTT). Using a time-lagged survey (6 months apart) of 71 employees, we found that the negative outcomes of perceived experienced coworker interpersonal mistreatment perpetuate after the individual quits and joins a new organization by negatively impacting the individual’s social integration via the individual’s rumination and reduced mental health. Contrary to our hypothesis, we did not find that the negative relationship between individuals’ reduced mental health and their social integration was weaker for those with high PTT. Overall, this study’s findings contribute insights into the extensiveness of the negative outcomes of experienced coworker interpersonal mistreatment. We conclude with a discussion of the theoretical and practical implications of our study. (PsycInfo Database Record (c) 2022 APA, all rights reserved)