Total U.S. credit card debt has almost doubled since 1988. Little is apparent from the aggregate data, however, about the composition of credit card debt growth. The author separates household data into two categories: changes in the number of households with credit cards, and changes in average credit card debt per household. His analysis reveals that higher average credit card debt per household is the primary reason for increased total credit card debt. Moreover, he finds that the principal contributors to the increase are households with above-average incomes rather than low-income households.