With the passage of the 1996 welfare reform law, numerous commentators expressed concern about the impact of welfare reform on young children of welfare recipients, while few expressed concern about adolescents. However, recent evidence suggests that adolescents are affected negatively when their parents participate in welfare-to-work programs. This research brief describes these negative impacts and explores possible explanations for the unexpected findings. Findings are presented from three experimental evaluations conducted in Canada, Minnesota, and Florida of welfare-to-work programs established before 1996 but including some of the reform law's key components. Negative effects included declines in achievement as well as increases in troublesome behavior such as smoking, drinking, drug use, and delinquent activity. Possible explanations for the findings are suggested and examined: (1) eroded adolescent-parent relationship quality; (2) decreased parental monitoring; and (3) shifting adolescent role in the family. The data provide some evidence that participation in welfare-to-work programs may lead to increased negative parenting behavior, limited evidence of small decreases in parental supervision, and evidence for a broader shift in adolescents' roles in the families, with adolescents taking on more adult-like roles. The brief concludes with key issues for policymakers to take into account when considering policies to support adolescent development in families affected by welfare reform, including establishing more after-school programs for adolescents, reducing the number of hours that adolescents work, and providing guidance to parents about levels of adolescent responsibility and autonomy. (Contains 25 endnotes.) (KB)