This document offers a brief examination of the key policy issues surrounding the EITC and marriage penalties. The EITC is designed to support low income working families with children. It provides a subsidy (up to $3,816 in 1999) for families with children and low earnings. Current research shows that the EITC has been successful in raising the income of such families, increasing rewards/incentives to work among many low skill workers, and in stimulating greater work effort by single parents. (Author abstract).