Food prices within States affect average monthly costs of State food benefits packages provided by the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) more than variations in WIC caseload composition do. In addition, cost-containment practices by State WIC agencies provide different levels of cost savings in different areas, which also contributes to interstate variation in benefits package costs. This study is one of the few to examine the degree to which food prices, caseloads, and cost containment practices influence costs of State WIC food benefits packages. Because few data exist on the actual food items that WIC participants purchase, the study used a scanner dataset of supermarket transactions and other sources to estimate the average monthly cost of WIC food benefits in several areas.