Noting that a central tenet of the 1996 welfare reform law was that work was the best way to improve the lives of single parents and their children, this fact sheet summarizes research on the impact of parental work on children in families receiving welfare. The fact sheet delineates key research findings from experimental studies of the effects of pre-1996 mandatory parental employment programs and earnings supplements on infants and toddlers, school-age children, and adolescents. Findings were drawn from 10 welfare demonstration programs measuring effects on school-age children, 16 programs measuring effects on adolescents, and 2 programs measuring effects on infants and toddlers. Findings indicated that school-age children benefit when their parents are in programs that increase both employment and income. Increasing mothers' employment without increasing family income did not help children on welfare. The two studies examining effects on infants and toddlers did not find evidence that these program harmed or benefited them. Adolescents had negative academic outcomes when their parents were involved in mandatory employment, earnings supplements, or time-limited assistance programs. Several possible explanations for the effects of the programs are identified. Implications for policy relate to the benefits of policies that increase family income, the lack of benefits for increasing work without increasing income, the importance of child care assistance, and the concern about adolescents' negative academic outcomes associated with increased parental employment, independent of family income increases. (KB)