2010 — This report calls attention to young people ages 10–24 within the populations considered most at risk of HIV infection: men who have sex with men, those who sell sex and those who inject drugs. Despite the growing attention that has been given to programming for these groups, little focus has been given to the needs of young people in these populations. At the same time, efforts to prevent HIV among young people have tended to focus on the general population. As a result, young people in most-at-risk groups are often not targeted in either type of programming. This report is based on the 2nd annual meeting of the Interagency Youth Working Group in 2009, which focused on young people most at risk of HIV, and on additional material from literature reviews and field experiences. The report concludes with suggested actions for addressing the needs of most-at-risk young people.