Wealth accumulation has important implications for the relative well-being of households. In this paper, we describe how household wealth in the United States varies by gender and family type. We find evidence of large differences in observed wealth between single-female-headed households and married couples. Although some of this gap reflects differences in observable characteristics correlated with gender and wealth – such as position in the life cycle, education, and family earnings – controlling for these characteristics reduces but does not eliminate the estimated wealth gap. The wealth holdings of single females in the U.S., controlling for these same characteristics, are also significantly lower than the wealth holdings of single males in the U.S. In contrast, observed wealth gaps between genders in a sub-sample of young households disappear when controlling for observable characteristics, suggesting either that these gaps are disappearing for younger households or that these gaps do not emerge until later in life.