We conceptualized work engagement as a mediator and person–supervisor fit as a moderator for understanding the impact mechanism of organizational commitment on turnover intention. With survey data collected from a sample of 512 building engineers in Taiwan, we tested the total effect moderation model that we proposed in this study via a path analysis procedure using a parametric bootstrap method. Results indicated that work engagement partially mediated the negative effect of organizational commitment on turnover intention, and that the negative relationship between organizational commitment and turnover intention became weaker when person–supervisor fit was closer. Implications for management theory and practice are discussed.