The wars in Iraq and Afghanistan brought renewed attention to the needs of veterans, including the needs of homeless veterans. Homeless veterans initially came to the country's attention in the 1970s and 1980s, when homelessness generally was becoming a more prevalent and noticeable phenomenon. The first section of this report defines the term "homeless veteran," discusses attempts to estimate the number of veterans who are homeless, and presents the results of studies regarding the demographic characteristics of homeless veterans as well as those surveyed as part of HUD's Annual Homeless Assessment Report to Congress. At the same time that the number of homeless persons began to grow, it became clear through various analyses of homeless individuals that homeless veterans were overrepresented in the homeless population. The second section of this report summarizes research regarding the overrepresentation of both male and female veterans, who have been found to be present in greater percentages in the homeless population than their percentages in the general population. This section also reviews research regarding possible explanations for why homeless veterans have been overrepresented. In response to the issue of homelessness among veterans, Congress has created numerous programs to fund services, transitional housing, and permanent housing specifically for homeless veterans. The third section of this report discusses these programs. The majority of programs are funded through the Department of Veterans Affairs. Within the VA, the Veterans Health Administration (VHA), which is responsible for the health care of veterans, operates all but one of the programs for homeless veterans. The Veterans Benefits Administration (VBA), which is responsible for compensation, pensions, educational assistance, home loan guarantees, and insurance, operates the other. In addition, the Department of Labor (DOL) and the Department of Housing and Urban Development (HUD) operate programs for homeless veterans. Several issues regarding homelessness among veterans have become prominent since the beginning of the conflicts in Iraq and Afghanistan. The fourth section of this report discusses three of these issues. The first is the VA's plan to end homelessness among veterans. A second issue is ensuring that an adequate transition process exists for returning veterans to assist them with issues that might put them at risk of homelessness. Third is the concern that adequate services might not exist to serve the needs of women veterans. Homelessness has always existed in the United States, but only in recent decades has the issue come to prominence. In the 1970s and 1980s, the number of homeless persons increased, as did their visibility. Experts cite various causes for the increase in homelessness. These include the demolition of single room occupancy dwellings in so-called "skid rows" where transient single men lived, the decreased availability of affordable housing generally, the reduced need for seasonal unskilled labor, the reduced likelihood that relatives will accommodate homeless family members, the decreased value of public benefits, and changed admissions standards at mental hospitals. The increased visibility of homeless persons was due, in part, to the decriminalization of actions such as public drunkenness, loitering, and vagrancy. Homelessness occurs among families with children and single individuals, in rural communities as well as large urban cities, and for varying periods of time. Depending on circumstances, periods of homelessness may vary from days to years. Researchers have created three categories of homelessness based on the amount of time that individuals are homeless. First, transitionally homeless people are those who have one short stay in a homeless shelter before returning to permanent housing. In the second category, those who are episodically homeless frequently move in and out of homelessness but do not remain homeless for long periods of time. Third, chronically homeless individuals are those who are homeless continuously for a period of one year or have at least four episodes of homelessness in three years. Chronically homeless individuals often suffer from mental illness and/or substance use disorders. Although veterans experience all types of homelessness, some evidence exists that they may be chronically homeless in higher numbers than nonveterans. Homeless veterans began to come to the attention of the public at the same time that homelessness generally was becoming more common. News accounts chronicled the plight of veterans who had served their country but were living (and dying) on the street. The commonly held notion that the military experience provides young people with job training, educational and other benefits, as well as the maturity needed for a productive life, conflicted with the presence of veterans among the homeless population. While the statutory definition of "homeless veteran" may seem straightforward, there has been some confusion in recent years over veteran eligibility for VA programs targeted to homeless veterans. Title 38 of the United States Code defines the term "homeless veteran" as "a veteran who is homeless (as that term is defined in section 103(a) of the McKinney-Vento Homeless Assistance Act)." The following subsections discuss the meaning of the terms veteran and homeless. The definition of "veteran" for purposes of Title 38 benefits (the title of the United States Code that governs veterans benefits) is a person who "served in the active military, naval, or air service, and who was discharged or released therefrom under conditions other than dishonorable." In addition, there may be more specific length-of-service and character-of-discharge criteria required for veterans to qualify for VA benefits and health care. Certain minimum length-of-service requirements apply to people who enlisted on or after September 8, 1980. The general requirement is the "full period" for which the servicemember was called or ordered to active duty or, if less, 24 months of continuous active duty. (For more information, see CRS Report R42324, Who Is a "Veteran"?—Basic Eligibility for Veterans' Benefits , by [author name scrubbed].) Regarding discharge status, the VA accepts discharges that are characterized as honorable or general (under honorable conditions) as "other than dishonorable" for VA benefit purposes. A dishonorable discharge disqualifies a veteran from eligibility for benefits. In between honorable and dishonorable discharges are other-than-honorable or bad-conduct discharges adjudicated by a special court martial, for which VA may make a character-of-discharge determination about a veteran's eligibility for benefits and health care. (For more information, see CRS Report R43928, Veterans' Benefits: The Impact of Military Discharges on Basic Eligibility , by [author name scrubbed] and [author name scrubbed].) Both length-of-service and character-of-discharge criteria have become issues in determining veteran eligibility for two VA homeless veteran programs administered by public entities or private nonprofit grantees (versus direct VA administration): the Homeless Providers Grant and Per Diem (GPD) program and the Supportive Services for Veteran Families (SSVF) program. In 2014, the VA office of General Counsel advised that VA GPD providers not serve homeless veterans unless they met eligibility criteria for VA health care (including length-of-service and character-of-discharge criteria). Similar guidance had been given to SSVF grantees. Previously, these criteria had not been required in determining eligibility for the GPD program, with the GPD program handbook basing eligibility on the definition of veteran and not further specifying length-of-service or character-of-discharge criteria. For about a month in 2014, the VA imposed a moratorium that only allowed veterans who qualified for VA health care to participate in the GPD program. Advocacy groups raised concerns that veterans most needing assistance, including those whose discharges may have resulted from mental health issues, would no longer have access to services. The VA quickly lifted the moratorium while awaiting an opinion from the Office of General Counsel about eligibility for the GPD program. As of the date of this report, the VA had not released an opinion as to eligibility. In both the 113 th and 114 th Congresses, legislation has been introduced to clarify veteran eligibility for the GPD and SSVF programs. In the 114 th Congress, S. 1731 , the Homeless Veterans Services Protection Act, which has been passed by the Senate, would waive the minimum continuous period of active duty requirement and allow other-than-honorably discharged veterans to qualify for services through the GPD and SSVF programs. Second, veterans are considered homeless if they meet the definition of "homeless individual" codified as part of the McKinney-Vento Homeless Assistance Act ( P.L. 100-77 ). Specifically, the statute defining homeless veteran refers to Section 103(a) of McKinney-Vento. McKinney-Vento lays out several ways in which someone may be considered homeless. Literal Homelessness: An individual or family is homeless if they lack a fixed, regular, and adequate nighttime residence, defined to mean: Having a primary nighttime residence that is a public or private place not designed for, nor ordinarily used as, a regular sleeping accommodation for human beings. These may include a car, park, abandoned building, bus or train station, or campground. Living in a supervised publicly or privately operated shelter designed to provide temporary living accommodations. These include transitional housing and hotels or motel rooms paid for by charitable institutions or government entities. Exiting an institution (such as a jail or hospital) after a stay of 90 days or fewer, and having resided in an emergency shelter or place not meant for human habitation prior to entering the institution. Imminent Loss of Housing: Individuals and families who meet all of the following criteria are considered homeless: They will "imminently lose their housing," whether it be their own housing, housing they are sharing with others, or a hotel or motel not paid for by a government entity.