This study is an attempt to examine whether Deci's hypotheses regarding the effects of performance-reward contingency, competition, and feedback outcomes—which have been investigated primarily among children and students—can also be applied to corporate employees. The issue of the detrimental effect of extrinsic rewards on intrinsic motivation is an important one, particularly given the rapid adoption of merit-based pay systems in Korean firms in recent years. Regression analysis results showed that intrinsic motivation is positively influenced by age, performance-reward contingency, positive feedback, and achievement orientation. Furthermore, the variables of age, performance-reward contingency, feedback outcomes, and achievement orientation all showed positive effects on the perceived importance of competence, which was set as the mediating variable in this study. However, only achievement orientation and feedback outcomes were found to have significant positive effects on perceived competence. Examining the influence pathways of variables through mediated regression analysis, variables such as age, performance-reward contingency, and achievement orientation contributed to intrinsic motivation by enhancing the perception of the importance of competence. Additionally, feedback outcomes and achievement orientation were found to contribute to intrinsic motivation through the process of instilling a sense of competence in individuals. Thus, the hypotheses regarding the mediating effects of the importance of competence and perceived competence were supported.