Drawing on the proactive motivation model and theories of motivation, the current study examined customer-initiated support as an antecedent of employees’ proactive customer service performance (PCSP) and investigated the mediating role of proactive motivations and the moderating role of serving culture. We conducted two multilevel studies to test the proposed hypotheses. In study 1, we collected diary data from 158 nurses across 10 working days, and results showed that the relationship between nurses’ daily experience of customer-initiated s...