In 2007, the Food and Nutrition Services of the U.S. Department of Agriculture issued an “Interim Rule” that substantially revised regulations governing the WIC food packages. State agencies administering the WIC Program at the state level were required to implement the revised food packages by October 2009. The WIC Food Packages Policy Options Study documents how state agencies responded to the Interim Rule. The Interim Rule introduced new food categories, revised maximum purchase quantities, and provided the option for state agencies to implement new food substitution policies under each of WIC’s seven food packages.