College debt refers to a form of debt that is owed for student loans, federal or private, taken out for costs associated with college attendance. It is an increasingly dominant feature in many young adults’ financial portfolios, although this varies in likelihood and amount across the population. The explosion of college debt is driven by increases in both returns on and costs of college education, declines in grant-based financial aid, stagnating household incomes, and financial innovations. The rising college debt is of social concern because it has important consequences, both positive and negative, for a number of life outcomes.