The Section 8 tenant-based assistance program plays a central role in federal housing policy for poor renters. In general, this program works well, but there are reasons to believe that it could be strengthened. Section 8 may not be achieving its full potential for promoting housing mobility and choice, especially for minority families with children. And in some communities, concerns are being raised about the implications of Section 8 for the neighborhoods in which recipients live. This report draws on the existing research literature and a fall 1999 symposium to summarize the current state of knowledge and debate on the issues of Section 8 mobility and neighborhood health.