The use of mainstream housing assistance programs will be essential if the nation is to achieve the goals of the 2010 Federal Strategic Plan to Prevent and End Homelessness, including ending chronic homelessness by 2015 and ending homelessness for families, youth, and children by 2020. The U.S. Department of Housing and Urban Development (HUD) has housing assistance programs specifically targeted to people experiencing homelessness, but those resources are small by comparison with the 2.5 million Housing Choice Vouchers (HCVs) and the 1.1 million public housing units managed by public housing agencies (PHAs) across the country. This study was commissioned by HUD’s Office of Policy Development and Research to provide a baseline understanding of the efforts made by PHAs to serve homeless households with mainstream housing assistance resources. Data were collected from PHAs throughout 2012 and early 2013 using two approaches: a Web-based survey of roughly 4,000 PHAs and follow-up telephone discussions with staff at 120 PHAs. The web survey achieved an 80% response rate, with 3,210 PHAs submitting data. HUD and the research team established three categories of effort a PHA may adopt to serve homeless households: 1) the establishment of a general preference for homeless households, 2) the establishment of a limited preference for homeless households, or 3) modifications to screening or changes to other policies or procedures to reduce barriers homeless households may face in using PHA programs. Overall, the survey revealed that 24% of PHAs, controlling 53% of all assisted housing units, make at least one of the three targeted efforts to serve homeless households. The final report documents the findings of the full study, including: the extent to which PHAs make efforts to serve households experiencing homelessness, the role of PHAs in broader community efforts to address homelessness, how PHAs identify and address barriers that people experiencing homelessness may face when accessing and utilizing PHA resources, how PHAs partner with community organization to serve homeless households, and options for encouraging greater efforts in serving homeless households among PHAs. A dataset resulting from the web-based census survey is also available for public use.