The causes of homelessness and determining how best to assist those who find themselves homeless became particularly prominent, visible issues in the 1980s. The concept of homelessness may seem like a straightforward one, with individuals and families who have no place to live falling within the definition. However, the extent of homelessness in this country and how best to address it depend upon how one defines the condition of being homeless. There is no single federal definition of homelessness, although a number of programs, including those overseen by the Department of Housing and Urban Development (HUD), Department of Veterans Affairs (VA), Department of Homeland Security (DHS), and Department of Labor (DOL) use the definition enacted as part of the McKinney-Vento Homeless Assistance Act (P.L. 100-77). The McKinney-Vento Act definition of a homeless individual was recently broadened as part of the Helping Families Save Their Homes Act of 2009 (P.L. 111-22). Previously, a homeless individual was defined as a person who lacks a fixed nighttime residence and whose primary nighttime residence is a supervised public or private shelter designed to provide temporary living accommodations, a facility accommodating persons intended to be institutionalized, or a place not intended to be used as a regular sleeping accommodation for human beings. The new law expanded the definition to include those defined as homeless under other federal programs, in certain circumstances, as well as those who will imminently lose housing. In the 112th Congress, a bill that would further expand the McKinney-Vento Act definition, the Homeless Children and Youth Act of 2011 (H.R. 32), has been approved by the House Financial Services Committee, Subcommittee on Insurance, Housing and Community Opportunity. A number of federal programs in seven different agencies, many originally authorized by the McKinney-Vento Act, serve homeless persons. These include the Education for Homeless Children and Youth program administered by the Department of Education (ED) and the Emergency Food and Shelter program, a Federal Emergency Management Agency (FEMA) program run by the Department of Homeland Security. The Department of Health and Human Services (HHS) administers multiple programs that serve homeless individuals, including Health Care for the Homeless, Projects for Assistance in Transition from Homelessness, and the Runaway and Homeless Youth program. This report describes the federal programs that are targeted to assist those who are homeless; includes recent funding levels; discusses current issues, including homelessness after the economic downturn and federal efforts to end homelessness; and provides information on recent legislation. Among active legislation are bills to reauthorize the Violence Against Women Act, which includes transitional housing for those who are homeless as a result of domestic violence (S. 1925 and H.R. 4970) and legislation that would, among other things, reauthorize the Education for Homeless Children and Youth program (H.R. 3989 and H.R. 3990).