Whereas much research has explored the causes and consequences of the gender wage gap, far less has examined earnings differentials within marriage. This article contributes to this literature by utilizing the 2000 wave of the 1979 National Longitudinal Survey of Youth to examine variation in husbands' and wives' relative income by race/ethnicity, human capital, labor supply, and life stage. The author finds that Black women's disproportionate concentration among high relative earning wives can be attributed more to their greater attachment to paid labor than to their husbands' labor supply. Nonetheless, Black women's odds of earning as much as or more than their husbands are greater than those of White women. In addition, unlike research on the motherhood wage gap more generally, the author finds that the impact of motherhood on women's earnings relative to their husbands can be largely explained by mothers' lower labor supply relative to their childless counterparts. (Contains 2 tables and 15 notes.)