To address homelessness among Veterans, a growing proportion of permanent supportive housing units supported by the U.S. Departments of Housing and Urban Development and Veterans Affairs Supportive Housing (HUD-VASH) program are allocated to programs where multiple Veterans with a history of homelessness live in a particular building, referred to as single-site housing. This mixed-methods study-including administrative data from Veterans who moved into HUD-VASH housing and qualitative data from focus groups with services providers at 10 single-site programs-describes the characteristics and needs of Veterans who moved into single-site HUD-VASH programs, the rationale for developing single-site HUDVASH programs, and the services provided in single-site programs that are responsive to Veterans' needs. Based on quantitative analyses, Veterans who were older and had chronic medical and mental health conditions and sought related care were at increased odds of receiving single-site housing. Qualitatively, we found that HUD-VASH programs developed single-site programs for two reasons: to ensure that the most vulnerable Veterans remained housed through the provision of supportive services and to increase housing options for hard-to-house Veterans, including those who require more support because of medical, mental health, or substance use disorders; physical disabilities; or lack of ability to live independently for other reasons. Due to the high needs of Veterans served by single-site programs, development of these programs should consider both space and staffing needs. Future research should assess the relationship between assignment to housing type and health and housing outcomes for participants as well as service enhancements to address Veterans' needs.