We examine changes in organizational identification among 1,346 newcomers at critical milestones during their first year. Integrating the social identity approach (Haslam, 2004) with the literature on psychological contracts (Rousseau, 1989), we argue that changes in newcomer perceptions of organizational prestige influences changes in their organizational identification over time, mediated by changes in their perceptions of the extent that their psychological contract has been fulfilled. Our five-wave results reveal that perceived prestige, psychological contract fulfillment and organizational identification rise during institutionalized socialization, then fall immediately after this period, and finally recover and stabilize as employees settle into their first assignment. Newcomers' personal prestige markers, including academic qualifications, the proportion of in-group members in the incoming cohort and organizational preferential treatment moderate these change patterns, which subsequently predict the speed and occurrence of their voluntary turnover over three years of employment.