The U.S. Department of Housing and Urban Development (HUD) is pleased to present this second national report to Congress on homelessness in America. The first Annual Homeless Assessment Report (AHAR) was submitted in February 2007. These reports were developed in response to a series of Congressional directives beginning with the FY 2001 HUD Appropriations Act. In that year, Congress directed the Department to assist communities to implement local Homeless Management Information Systems (HMIS) and required every jurisdiction to have client-level reporting within three years. Senate Report 106-410 noted that HMIS data could be used to develop an unduplicated count of homeless people and to analyze the use and effectiveness of homeless assistance services. To that end, Congress further charged the Department with collecting and analyzing HMIS data from a representative sample of communities in order to understand the nature and extent of homelessness nationally. The second AHAR makes use of two primary data sources. The first source is HMIS data on the number, characteristics, and patterns of shelter use among sheltered homeless persons - or persons who used emergency and transitional housing—during a six-month period from January 1 through June 30, 2006. The data were obtained from a nationally representative sample of communities. A total of 58 sample sites participated in the second AHAR, including 49 communities that participated in the first AHAR and 9 new sample communities that were not able to provide data for the first report. Because some sample communities are still working to secure the participation of homeless assistance providers in HMIS, not all could provide data for this analysis (or could provide only partial data). As a result, the estimates provided in this report have large confidence intervals (i.e., sampling error).