The Food and Nutrition Service (FNS), which administers the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), asked Mathematica Policy Research to examine more closely Medicaid's role in adjunct eligible for WIC and do not have to show further proof of income to qualify. FNS wanted to explore whether Medicaid may have expansive effects on the WIC program by allowing persons who have incomes above 185 percent of the federal poverty line (the income eligibility standard for WIC) to qualify for WIC through Medicaid. This study was motivated, in part, by apparent discrepancies between FNS's estimates of WIC eligibles based on data from the Current Population Survey (CPS) and the number of WIC participants according to administrative data.