Although economic mobility is an objectively defined term, lay beliefs about mobility—the configuration of ideas and attitudes about economic mobility that is not necessarily grounded in economic data—are often formed in a subjective manner. Drawing on research from the United States and beyond, we propose a novel framework for understanding how people construe, think about, and understand economic mobility. We highlight the importance of systematically examining the type, time frame, trajectory, and target of mobility that people have in mind for understanding when they most and least strongly believe in it. In addition, our framework offers a conceptual roadmap for examining the factors that influence lay beliefs about mobility, including individual differences in these lay beliefs and their important downstream consequences. Finally, we outline several important open questions that are highlighted by our framework as a guide for future research on lay beliefs about economic mobility.