Recognizing that most poor families are single-parent families, the federal welfare reform law of 1996 emphasized the responsibility of both parents to support their children. In addition to strengthening the child support enforcement system, the law included several provisions designed to decrease childbearing outside of marriage and to promote two-parent families. This article focuses on the important role that fathers play in children's lives and how public policies have affected childbearing and father involvement. Key observations are: Compared with children living with both biological parents, children in father-absent families often have fewer economic and socioemotional resources from their parents, and do not fare as well on many outcome measures. Efforts to reduce the rising number of father-absent families by focusing on preventing unwanted pregnancy among unmarried women, especially teen girls, have met with some success; those programs seeking to alter adolescents' life opportunities in addition to providing education or family planning services appear to hold the most promise. Efforts to encourage greater father involvement by focusing almost exclusively on increasing absent parents' child support payments reap only minimal benefits for poor children because their absent parents often have few resources and little incentive to make support payments. To date, efforts to increase the emotional involvement of unmarried fathers with their children have produced disappointing results, but new research suggests that such programs can make a difference when targeting fathers at the time of a child's birth. Many children spend some time living away from their fathers, deprived of the financial and emotional resources they can provide. Because of the importance of fathers to child well-being, the authors conclude that new directions in research and public policies are needed to encourage greater father involvement across the wide diversity of family arrangements in society today.