To sort out the pros and cons of using the tax system to enact social policy goals, in particular to help low-income families, the Urban Institute convened a tax policy forum in Washington, D.C., on June 21, 2001. The discussion revealed that using the tax system as a social policy tool is a much more complex and subtle undertaking than would appear to be the case from many popular announcements. This publication draws on the forum discussion to present an overview of the issues involved in using the tax system to promote social goals.