Social capital theorists have shown that inequality arises in part because some people enjoy larger, more supportive, or otherwise more useful networks. But why do some people have better networks than others? This book argues that the answer lies less in people's deliberate “networking” than in the institutional conditions of the churches, colleges, firms, gyms, and other organizations in which they happen to participate routinely. This book introduces a model of social inequality that takes seriously the embeddedness of networks in formal organizations, proposing that what people gain from their connections depends on where those connections are formed and sustained. The model is illustrated and developed through a study of the experiences of mothers whose children were enrolled in New York City childcare centers. As a result of the routine practices and institutional conditions of the centers—from the structure of their parents' associations, to apparently innocuous rules such as pick‐up and drop‐off times—many of these mothers dramatically increased their social capital and measurably improved their wellbeing. Yet how much they gained depended on how their respective centers were organized. This book identifies the mechanisms through which childcare centers structured the networks of mothers, and shows that similar mechanisms operate in many other routine organizations, from beauty salons and bath houses to colleges and churches. The book makes a case for the importance of organizational embeddedness in the study of personal ties.