Each month, the Commodity Supplemental Food Program (CSFP) provides supplemental food packages to about a half a million low-income pregnant and postpartum women, children younger than 6, and seniors 60 and older. This study—the first in-depth study of the program since 1982—looks at how CSFP operates, who participates in it, and how it fits into the overall food assistance landscape. The study estimates that 2.9 million mothers, infants, and children meet eligibility requirements for CSFP but not for the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). An estimated 7.5 million seniors would be eligible if CSFP were available everywhere. In eight States where the program is widely available, more seniors participate in CSFP than in the Food Stamp Program. Use of volunteers, staff stability, and the small scale of operations contribute to CSFP’s simplicity and accessibility. Focus group participants liked the program’s simplicity, the quality of the food it provides, and the nutrition education they received.