The Supplemental Nutrition Assistance Program (SNAP) helps working families meet their nutritional needs. Families whose earned income increases in a given month may have their SNAP benefits abruptly reduced or cut off in the following month. Using sentinel sample data from 2007-15 for families with children younger than age four, we investigated how SNAP benefit reductions or cutoffs resulting from increased income were related to economic hardships (food and energy insecurity, unstable housing, forgone health and/or dental care, and health cost sacrifices) and to caregiver and child health. After we controlled for covariates, we found that the groups whose SNAP benefits were reduced or cut off had significantly increased odds of household and child food insecurity, compared to a group with consistent participation in SNAP. Reduced benefits were associated with 1.43 and 1.22 times greater odds of fair or poor caregiver and child health, respectively. Policy modifications to smooth changes in benefit levels as work incomes improve may protect working families with young children from increased food insecurity, poor health, and forgone care.T he Supplemental Nutrition Assistance Program (SNAP) is the primary public assistance program that helps low-income working families with children, seniors, and people with disabilities purchase food. SNAP can buffer participants against food insecurity (inadequate access to enough nutritious food for an active and healthy life) 1 and poor health. 2 Food insecurity is associated with multiple negative health, developmental, behavioral, and educational outcomes among children and adolescents and with physical and mental health problems among adults. [3][4][5][6][7][8][9] SNAP benefits are frequently insufficient for the consistent purchase of a healthful diet. Nevertheless, among SNAP-eligible households, SNAP participation is associated with greater food security and improved health, educational, and economic outcomes, compared to not participating. 3,4,[10][11][12] Additionally, SNAP makes a positive difference over the life course: SNAP participation in early childhood is associated with decreased risk of later metabolic syndrome and, among women, increased economic selfsufficiency. 13 Other studies have examined SNAP and children's health and food security in the context of the relative generosity of state policies that determine benefit levels 14,15 and whether food price variations across states change SNAP purchasing power and thus child outcomes. 4 In addition to promoting family health and well-being, SNAP functions as a work support. In fiscal year 2016, 55 percent of participating SNAP households with children had earned income, including 67 percent of multiple-adult