Eighteen years have passed since repeal of what was the nation's major cash welfare program assisting low-income families with children, the Aid to Families with Dependent Children (AFDC) program, and its replacement with a block grant of Temporary Assistance for Needy Families (TANF). This report focuses on trends in the economic well-being of female-headed families with children, the principal group affected by the replacement of AFDC with TANF. Female-headed families and their children are especially at risk of poverty, and children in such families account for well over half of all poor children in the United States. For these reasons, single female-headed families continue to be of particular concern to policymakers. The report details trends in income and poverty status of these families, prior and subsequent to enactment of the 1996 welfare reform law and other policy changes. The report focuses especially on welfare dependency and work engagement among single mothers, a major dynamic that welfare reform and accompanying policy changes have attempted to affect. It also examines the role of programs other than TANF in providing support to single female-headed families with children.