This study investigated how supervisors' coaching behavior affects employees' job engagement. In particular, it was predicted that self-efficacy and job meaningfulness would mediate the relationship between supervisors' coaching behavior and employees' job engagement. That is, as supervisors' coaching behavior improves, employees' belief in their own abilities and their perception of the importance of their work would increase, which in turn would enhance job engagement. Furthermore, it was predicted that the relationships between supervisors' coaching behavior and both self-efficacy and job meaningfulness would be moderated by the trust relationship with the supervisor.

The analysis results showed that a statistically significant positive relationship exists between coaching behavior and job engagement. In particular, the relationship between coaching behavior and job engagement was found to be fully mediated by self-efficacy and job meaningfulness. Additionally, the relationships between supervisors' coaching behavior and both self-efficacy and job meaningfulness were found to be moderated by trust. Specifically, the relationships between coaching behavior and self-efficacy, as well as between coaching behavior and job meaningfulness, were stronger in groups with high trust in their supervisors compared to groups with low trust. In conclusion, this study confirms that supervisors' coaching behavior can produce positive effects, and that when a trust relationship with the supervisor is established, some of these positive effects can be further enhanced.