As described in earlier articles, children whose parents have higher income and education levels are more likely to grow up in stable two-parent households than their economically disadvantaged counterparts. These widening gaps in fathers' involvement in parenting and in the quality and stability of parents' relationships may reinforce disparities in outcomes for the next generation. This paper reviews evidence about the effectiveness of two strategies to strengthen fathers' involvement and family relationships--fatherhood programs aimed at disadvantaged noncustodial fathers and relationship skills programs for parents who are together. Fatherhood programs have shown some efficacy at increasing child support payments, while relationship skills approaches have shown benefits for the couples' relationship quality, coparenting skills, fathers' engagement in parenting, and children's well-being. The research evidence suggests that parents' relationship with each other should be a fundamental consideration in future programs aimed at increasing low-income fathers' involvement with their children. (Contains 2 figures and 4 notes.) [A version of this paper (and four other policy papers) was presented at the Institute for Research on Poverty (IRP) conference on "Young Disadvantaged Men: Fathers, Families, Poverty, and Policy" which was held September 14-15, 2009, at the University of Wisconsin-Madison.]