We study whether SNAP mediates the effect of food insecurity on future health and healthcare utilization more for the extreme poor (i.e., those with income below 50% of the poverty line) than it mediates the effect for other low-income families (i.e., with incomes between 50% and 200% of the poverty line). We use data for about 23,000 people in the 2011-2012, 2012-2013, and 2013-2014 linked NHIS-MEPS surveys with the measures of food insecurity coming from the NHIS and the measures of SNAP benefits and various health outcomes from the MEPS. We find that SNAP significantly reduces the negative effects of food insecurity on several measures of health and healthcare-related outcomes for nonelderly adults, and that this reduction is often significantly greater for those in extreme poverty. However, we find no significant effects of this type for children. In addition, attempts to control for possible endogeneity of the SNAP effect of interest are unsuccessful because of a lack of strong instruments. Nevertheless, endogeneity of the effect of interest maybe biased downward, strengthening the support of the OLS estimates as valid.