Introduction: Half of individuals eligible for the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), a federal nutrition program, are not enrolled. This dissertation examines associations between (1) national policy change, (2) neighborhood opportunity, and (3) experiences of racial discrimination on WIC participation, with a focus on children of Hispanic, non-Hispanic Black, and immigrant mothers.

Methods: The data for this study were drawn from the 2013-2024 iterations of Children’s HealthWatch, an annual cross-sectional study among mothers with children ages 0-4. Aim 1 is an interrupted time series analysis examining differences in WIC participation by maternal nativity after a federal policy (the public charge rule) was changed. Aim 2 is a cross-sectional study of the association between neighborhood opportunity, measured by the Child Opportunity Index, and WIC participation. Aim 3 is a cross-sectional study which describes the association between experiencing racial discrimination and dropping out of WIC.

Results: After the public charge rule changed, WIC participation decreased significantly faster among children of immigrant mothers with a shorter length of residence in the US, relative to children of US-born mothers. The prevalence of WIC participation was significantly higher among respondents from lower opportunity neighborhoods compared to higher opportunity ones. Lifetime experiences of racial discrimination were significantly associated with WIC drop-out.

Conclusions: All three factors evaluated were significantly associated with WIC participation, which can inform targeted outreach strategies. Further studies that employ community-engaged approaches are needed to understand and improve the WIC experience among all mothers and children to increase enrollment and participation.