A class ceiling persists in organizations. People from a lower social class are often paid less and attain leadership roles less frequently than those from a higher social class, even when their educational credentials are comparable. In the current research, we argue that a contributing factor to this class ceiling is the class difference in the propensity to negotiate. Specifically, we posit that lower-class individuals are less inclined to initiate negotiation compared to their higher-class counterparts. This, in turn, exacerbates economic inequality. We provide empirical support for this hypothesis across an archival analysis of a nationally representative employee dataset (Study 1), a survey about workplace negotiation (Study 2), and a field study in an online labor market (Study 3). This class disparity in negotiation propensity is explained by differences in sense of power and fear of social backlash. A final experiment shows that the fear of social backlash experienced by lower-class individuals reflects realistic perceptions of differential treatment (Study 4). Lower-class negotiators face greater social penalties compared to their higher-class counterparts. Thus, our studies advance the research on social class and negotiation in organizations and highlight the role of negotiation as both a hindrance and an opportunity for upward mobility.