Across cultures, the idea of money has dual positive and negative connotations. Consistent with this notion of duality, money-priming theory posits that the salience of money makes individuals work harder for themselves while also reducing the concern they have for others. Although research has tended to support these expectations, it has almost exclusively done so using between-persons designs in controlled lab settings. To address these limitations in the literature, we used a within-persons design in two work settings to test individual behavior change as a function of the salience of money. We did so using two samples of professional athletes and tested the extent to which priming individual pay affected both self-serving and cooperative behaviors. We operationalized the money prime in these samples as the final year of individuals’ employment contracts—a time when money is made particularly salient relative to surrounding years. Consistent with money-priming theory, within-persons analyses using a sample of basketball players from the National Basketball Association revealed that self-serving behaviors significantly increased in the final contract year relative to surrounding years. However, we did not find that cooperative behaviors decreased during the final contract year. This pattern of results was replicated using a sample of professional hockey players in the National Hockey League. These findings cumulatively suggest that although the salience of money is associated with increases in self-serving behaviors, it is not adversely associated with cooperation or team success.