This report estimates the number of women, infants, and children eligible to receive benefits from the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in 2018, with updated estimates for 2016 and 2017. It includes WIC eligibility estimates for the nation and by region, state, and U.S. territory. The national estimates use data from the Current Population Survey’s Annual Social and Economic Supplement (CPS-ASEC) to create a national estimate of infants and children eligible for WIC and the average monthly number of infants, children, and pregnant and postpartum women eligible for WIC. The state estimates use data from the American Community Survey (ACS) data and each state’s share of the ACS-based estimates. Estimates for the U.S. territories use the Puerto Rico Community Survey data and Census Bureau International Database to estimate WIC eligibility in Puerto Rico and the other U.S. territories, respectively. In the 2018 report, the 2016 and 2017 estimates were updated to use the new CPS-ASEC processing system.