This research aimed to empirically test the conceptual model of strengthening employee resilience during the post-integration phase of the organizational integration process (Khan et al., 2020) that assumes the mediating role of various aspects of organizational justice in the relationship between (non) financial rewards and employee resilience. Within a strong methodological approach to data collection, at two points in time, on a sample of N = 991 employees, this research aimed to capture the complex interplay between these constructs – not only in the post-integration but also in the phase between pre-integration and integration of the organizational integration process. This method enabled the study of developmental dynamics of observed interrelationships between constructs, while adapting to one of the most demanding types of organizational change – organizational integration. The results have shown that the developmental dynamic of the organizational integration process is reflected by significantly different interrelations of the observed constructs in the post-integration, as opposed to the (pre)integration phase. In line with the conceptual model, non-financial rewards (as compared to financial ones) during the post-integration phase of the organizational integration process proved to be a stronger and more significant positive predictor of employee resilience, while in the (pre)integration phase, the two types of rewards had the same importance in explaining employee resilience. In the (pre)integration phase, distributive, procedural, and interactional justice are equally strong mediators of the relationship between (non)material rewards and employee resilience, while in the post-integration phase, distributive justice is by far the strongest positive mediator of the relationship between (non)material rewards and employee resilience. Precisely because a large number of organizational integrations often fail, understanding the role and interrelationships of the reward system, justice, and employee resilience, and the way in which these constructs function at different stages of organizational integration can make the adaptation to this process less destructive; therefore, the findings of this research have important practical implications.

employee resilience, (non)financial rewards, organizational justice, organizational integration, mergers and acquisitions