The American Recovery and Reinvestment Act of 2009 increased benefit levels for the Supplemental Nutrition Assistance Program (SNAP, formerly known as the Food Stamp Program) and expanded SNAP eligibility for jobless adults without children. One goal of the program changes was to improve the food security of low-income households. The authors of this report find that food expenditures by low-income households increased by about 5.4 percent and their food insecurity declined by 2.2 percentage points from 2008 to 2009. Food security did not improve for households with incomes somewhat above the SNAP eligibility range. These findings, based on data from the nationally representative Current Population Survey Food Security Supplement, suggest that the ARRA SNAP enhancements contributed substantially to improvements for low-income households.