Past work suggests that children have an overly rosy view of rich people that stays consistent across childhood. However, adults do not show explicit pro-rich biases and even hold negative stereotypes against the rich (e.g., thinking that rich people are cold and greedy). When does this developmental shift occur, and when do children develop more complex and differentiated understandings of the wealthy and the poor? The current work documents the developmental trajectory of 4-12-yr-old primarily American middle-class children's conceptualizations of the wealthy and the poor (total N = 164). We find: (1) age-related decreases in pro-rich preferences and stereotypes relative to the poor; (2) domain-sensitive stereotypes across prosociality, talent, and effort; (3) resource-specific behavioral expectations such that with age children increasingly expect the wealthy to contribute more material resources but not more time than the poor; (4) an increasing recognition of the unfairness of the wealth gap between the wealthy and the poor; and (5) a developing understanding of the link between wealth and power. In sum, this work illuminates the emergence of more complex understandings of wealth, poverty, and inequality.