This study investigates how workforce differentiation affects organizational justice and perceived organizational support (POS). Based on theories of organizational justice and social exchange, it is hypothesized that workforce differentiation affects POS via perceptions of overall organizational justice, such that a higher workforce category ranking of an employee leads to increased perceptions of organizational justice. Organizational justice, in turn, is hypothesized to a positive relationship with POS. The results show empirical support for the hypothesized mediation process. In addition, several hypotheses about the moderating influence of individual differences on these relationships are put forward and tested.