Drawing on the Job Demands-Resources (JD-R) model, this study examined processes through which informal workplace family resources influence service performance. Our findings reveal that family supportive supervisor behavior (FSSB) and perceived organizational family support (POFS) relate to work engagement directly and indirectly through satisfaction with work-family balance which, in turn, relates to service performance through work engagement. Furthermore, we find that employee expertise negatively interacts with work engagement to influence service performance, suggesting that employee expertise compensates for low engagement in predicting service performance.