In the 1996 overhaul of federal welfare legislation, Congress included provisions to promote employment, marriage, and responsible fatherhood to prevent poverty among low-income families. Little previous research has focused on how marriage promotion policies construct paternal identity. Drawing on data from an 18-month study of a federally funded relationship skills program for low-income, unmarried parents, I analyze how responsible fatherhood policies attempt to shape ideas of successful fatherhood and masculinity in the service of the government’s pro-marriage, antipoverty agenda. The program promoted a class-specific version of what I call marital masculinity, one that seeks to redefine marriageability for low-income men by claiming that marriage comes before financial success and encourages fathers to earn more. It did this by targeting fathers’ masculine identities in two ways: first, by emasculating fathers who only provide financially for their children, and second, by promoting a highly gendered conception of paternal caregiving. By analyzing how this strategy can be understood as both empowering and controlling for low-income men, this research adds to the sociological literature on how welfare policies shape paternal identity and gendered family practices.