Racial disparities arise across many vital areas of American life, including employment, health, and interpersonal treatment. For example, one in three Black children lives in poverty (versus one in nine white children), and, on average, Black Americans live four fewer years compared with white Americans. Which disparity is more likely to spark reduction efforts? We find that highlighting disparities in health-related (versus economic) outcomes spurs greater social media engagement and support for disparity-mitigating policy. Further, reading about racial health disparities elicits greater support for action (e.g., protesting) compared with economic- or belonging-based disparities. This occurs in part because people view health disparities as violating morally sacred values, which enhances perceived injustice. This work elucidates which manifestations of racial inequality are most likely to prompt Americans to action.