In 2010, over 40 percent of families receiving cash assistance through the Temporary Assistance for Needy Families (TANF) program were “child-only,” meaning the adults in the household were not included in the benefit calculation, and aid was provided only for the children. TANF and child welfare programs provide cash assistance and other services that support children living with nonparent caregivers. The U.S. Department of Health and Human Services (HHS) Administration for Children and Families (ACF) oversees TANF and child welfare programs, which are administered by states. GAO was asked to examine the (1) trends and composition of the child-only caseload, (2) characteristics of caregivers and children in nonparent child-only cases, (3) factors influencing the level of benefits and services for children with non-parent caregivers, and (4) coordination efforts between state TANF and child welfare programs. GAO analyzed federal TANF and child welfare data; surveyed states; interviewed HHS officials and researchers; and conducted site visits in Tennessee, Texas, and Washington, selected for variation in TANF caseload characteristics and implementation of programs to support relative caregivers. Between fiscal years 2000 and 2008, TANF child-only cases increased slightly but represented a greater share of the overall TANF caseload because cases with adults in the assistance unit experienced a significant decline. The national composition of the TANF child-only caseload has remained relatively unchanged since 2000. At the end of 2010, the majority of children receiving TANF lived with parents who were ineligible for cash assistance, and one-third lived with nonparent caregivers who were relatives or unrelated adults. However, this composition varies by state. For example, in Tennessee, almost 60 percent of the TANF child-only caseload included children living with nonparent caregivers, compared with about 30 percent in Texas. Most nonparent caregivers in TANF child-only cases are unmarried women who are over 50 years old, and research suggests that they often have low incomes and health problems. The children tend to be related to their caregiver, who is often a grandparent, and they remain on assistance for at least 2 years. Some of these children live with nonparent caregivers as a result of parental abuse or neglect, substance abuse, incarceration, or mental illness, but these circumstances may or may not be known by the child welfare agency. The level of benefits and services available to children living with nonparents depends on the extent to which a child welfare agency becomes involved in the family’s situation and the licensing status of the caregiver. Children in foster care with licensed foster parents are generally eligible for greater benefits and services than children in other living arrangements, who may receive TANF child-only assistance. For one child, the national average minimum monthly foster care payment is $511 while the average TANF child-only payment is $249. Most children live with relatives who do not receive foster care payments because they are not licensed foster parents or they are in informal arrangements without child welfare involvement. Other factors influencing the assistance made available to children in a relative’s care include available federal funding, state budget constraints, and increased state efforts to identify relative caregivers to prevent children from being placed in the foster care system. Several state and local efforts are under way to coordinate TANF and child welfare services to better serve children living with relative caregivers, but information sharing is a challenge. Coordination efforts include colocating TANF and child welfare services and having staff from each agency work together to help relative caregivers access services. ACF currently provides grants to states and tribes to support collaboration between TANF and child welfare programs and plans to disseminate the findings. However, information and data sharing between the two programs does not occur consistently, which can hinder relatives’ access to available benefits. For example, although HHS provides funding, guidance, and technical assistance to promote data sharing between TANF and child welfare programs, more than half of states reported obstacles to sharing data, such as privacy concerns. GAO recommends the Secretary of HHS direct ACF to provide more guidance on data sharing opportunities. HHS agreed with GAO’s recommendation.