Performance pay has been one of the main trends in public sector reform over the last decade and aims to increase employees’ motivation. However, positive results are sparse. In a majority of cases, pay scheme designers neglect that intrinsic motivation may be distorted by the introduction of extrinsic rewards (crowding out). Nevertheless, under certain conditions, performance pay schemes may also enhance intrinsic motivation (crowding-in). The perception of rewards has proven to be an especially crucial factor for the outcome of performance pay. Based on psychological contract theory, this paper analyzes the relationships between intrinsic motivation, public service motivation (PSM), personality characteristics, and the design of the performance- appraisal scheme. The empirical analysis relies on a structural equation modeling (SEM) approach. Model findings reveal that a fair, participatory, and transparent design reduces the controlling perception while fostering the intrinsic motivation of employees. In addition, participants who score high on neuroticism perceive performance pay schemes to be more controlling and have lower values of intrinsic motivation.