What GAO FoundDefinitional differences of homelessness have posed challenges to providing services for children and youth. Children and youth living in precarious situations, such as living with others or in hotels, historically were excluded from receiving government-funded services. Congress enacted the Homeless Emergency Assistance and Rapid Transition to Housing Act of 2009 (HEARTH Act), which broadened the general definition of homelessness and provided greater statutory specificity concerning those who should be considered homeless. In November 2011, HUD issued a final rule on the definition of homelessness, adding a new category of homelessness––unaccompanied youth, and families with children and youth who are defined as homeless under other federal statutes. The HEARTH Act and HUD’s recent definition changes may alleviate some challenges previously faced by children and youth in accessing services, but not enough time has passed to assess the impact of those changes. Some children and youth who previously were not considered homeless by HUD will now qualify as homeless. However, the broadening of the definition does not mean that everyone who meets the new definition would be entitled to benefits in all homeless assistance programs, and constraints on resources will likely continue to restrict access for some children and youths.As of December 2011, the U.S. Interagency Council on Homelessness (Interagency Council) and federal agencies had taken steps to develop a common vocabulary for discussing homelessness and related terms, as GAO recommended in its June 2010 report. In January 2011, the Interagency Council convened a meeting of experts to discuss the development of a common vocabulary and the extent to which differences in definitions create barriers to accessing services. The Interagency Council issued a report to Congress in June 2011 that summarized the feedback received during the meeting. The report notes that a common vocabulary would allow federal agencies to better measure the scope and dimensions of homelessness, and may ease program implementation and coordination. As of December 2011, Interagency Council staff told GAO that they held three meetings––in August, September, and October 2011––to discuss implementation of a common vocabulary and data standard with key federal agencies such as HUD; the Departments of Commerce, Education, Health and Human Services (HHS), Labor, and Veterans Affairs (VA); and the Social Security Administration. The Interagency Council also noted that individual federal agencies have taken some positive steps to create this common data standard and improve coordination across agencies. For example, HHS and VA have been working with HUD to plan the potential transition of some of their programs to HUD’s data system (Homelessness Management Information Systems). As GAO has reported in the past, a common vocabulary would allow agencies to collect consistent data that agencies could compile to better understand the nature of homelessness, and it would allow agencies to communicate and collaborate more effectively.Why GAO Did This StudyAccording to the Department of Housing and Urban Development’s (HUD) estimates of shelter use, the number of homeless families increased by 20 percent from 2007 to 2010 and families currently represent a much larger percentage of the shelter population than ever before. Multiple federal agencies administer programs designed to address the needs of children and youths experiencing homelessness, but some programs use different definitions of homelessness to determine eligibility. The definitions range from people living in emergency or transitional shelters or on the street to those living with others because of economic hardship or living in motels or campgrounds because they lack other adequate alternative accommodations.This testimony discusses differences in the federal definitions of “homelessness” and other factors that may influence the effectiveness of programs serving persons experiencing homelessness, including children and youth. In completing this statement, GAO reviewed and updated, as appropriate, its June 2010 report, Homelessness: A Common Vocabulary Could Help Agencies Collaborate and Collect More Consistent Data (GAO-10-702). In that report, GAO recommended that federal agencies develop a common vocabulary for homelessness and determine whether it would be cost-effective to use this common vocabulary to develop and implement guidance for collecting consistent federal data on housing status. The agencies agreed with our recommendations. This statement also discusses the progress federal agencies have made in implementing these recommendations.