The goal of this study was to examine changes in newcomers’ psychological contract over time. Based on schema theory and the post-violation model of the psychological contract, we theorized that psychological contract fulfillment is strengthening the psychological contract over time, while changes in the psychological contract are most likely to occur in a situation of low employer and employee fulfillment. In a sample of newcomers in a Brazilian public organization, we tested how the fulfillment of both employer and employee obligations explain the change in the psychological contract. The results support the hypotheses, and we found that the highest level of change in psychological contracts occurred when the fulfilments of the obligations of both parties were low. We discuss the implications for theory on the change in psychological contracts.