With the ability and the funds to implement programs on a national level, federal policy is a potentially potent tool in primary prevention. Despite the U.S. government's history of ambivalence toward intervening in child rearing and limited national support for primary prevention, several initiatives have been implemented for children and families with some measure of success. The successes, however, are mitigated by limitations of the initiatives themselves and by the inconclusive nature of much of the evaluation data. This review of 5 federal policy-based initiatives for children and families provides the backdrop for discussing aspects of federal prevention program design, implementation, policy, and research.