Objective: To evaluate the impact of the 2009 food package changes for the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) on the availability of healthful food. Design: Survey of all food stores in the study area before and after the changes were implemented. Setting: Two low-income neighborhoods in Philadelphia, 1 predominantly African-American, the other predominantly Hispanic. Participants: One hundred forty one supermarkets, grocery stores, and non-chain corner stores identified through field enumeration. Main Outcome Measures: Nutrition Environment Measure Survey for Stores (NEMS-S) to determine availability, price, and quality of fruit, vegetables, milk, cereal, beans, canned fish, meat, whole grains, and juice. Analysis: Comparison of NEMS-S scores before and after food package changes using t tests and ordinary least squares regression to understand the role of supermarket status, WIC participation, and racial and income composition in predicting NEMS-S scores; geographic information systems to calculate proximity of residents to food stores. Results: The availability of healthful food increased significantly in stores, overall, with more substantial increases in WIC-authorized stores. Supermarket status, WIC retail status, and NEMS-S scores at baseline were significant predictors of NEMS-S scores after the food package changes. Conclusions and Implications: Changes in the WIC food package were associated with increased availability of healthful food in 2 low-income neighborhoods. (Contains 4 tables and 2 figures.)