The 2010 Annual Homeless Assessment Report (AHAR) represents the sixth in a series of reports on homelessness in the U.S. It responds to a congressional directive that the Department of Housing and Urban Development (HUD) provide an annual report to Congress on the extent and nature of homelessness. As in past years, the AHAR provides the results of local counts of people homeless on a single night in January, as well as estimates of the number, characteristics, and service patterns of all people who used residential programs for homeless people during the 2010 federal Fiscal Year (October 2009-September 2010). Also, for the first time, this year’s AHAR includes information about the use of permanent supportive housing (PSH) programs and the Homelessness Prevention and Rapid Re-Housing Program (HPRP). Altogether, the 2010 AHAR is the first report to provide national estimates on the use of the full continuum of homeless assistance programs—from homelessness prevention to homeless residential services to permanent supportive housing.