At least since the early twentieth century, informal specialized prostitution courts have tried to double as social welfare agencies. For this reason, prostitution courts illustrate in particularly explicit ways how public welfare administration and criminal court administration share similar ideas and practices and how these ideas and practices reinvent themselves over time. Cohen’s Article traces three moments of prostitution court reform in New York City: the New York Women’s Court that opened in Manhattan in 1910, the Midtown Community Court that opened in Manhattan in 1993, and four new prostitution courts that opened in New York City in 2013. It examines how court reformers in each moment used informal procedure to promote social welfare, social control, and individual responsibility, and it ties each approach to changing conceptions of the American welfare state. Ultimately, the Article argues that the genealogy of prostitution courts illuminates for the present how court reformers are using the language of trauma to negotiate the welfare logics of today.