Summary: In the wake of welfare reform, states could charge administrative costs, such as participant eligibility determinations, directly to the Food Stamp Program or Medicaid. This raised the possibility that states could receive duplicative reimbursements for these expenses--through the Temporary Assistance for Needy Families (TANF) block grants and from the programs directly. As a result, Congress required the Department of Health and Human Services (HHS), which is responsible for TANF and Medicare, to determine how much of the common administrative costs for determining eligibility were being charged to the Food Stamp Program and Medicaid. Congress also required the Department of Agriculture, which runs the Food Stamp Program, to reduce federal reimbursements to states for administrative costs for the Food Stamp Program by an amount equal to HHS' determination for this program. This report (1) summarizes HHS' administrative cost determinations, related estimates provided by the states to HHS, and the reasons for any differences between HHS' determinations and the states' estimates and (2) assesses the reliability of HHS' determinations. GAO focuses on that portion of common administrative costs that could have been charged to the Food Stamp Program.