This report provides the most recent data on the food security of United States households. Based on studies using the Food Security Core Module (FSCM), a tool facilitating direct documentation of the extent of food insecurity and hunger caused by income limitations, this report summarizes 35 studies representing 20 states and Canada. The report is presented in three parts. Part 1 provides information on concepts, definitions, and resources related to food security measurement. Part 2 contains three indices to help readers locate material: (1) study location index; (2) population group/topic index; and (3) state index. Part 3 contains study summaries, each presented in two formats. The first provides information on the objectives, methods, and key findings and conclusions of the study along with information on obtaining the report. The second is a technical summary giving more detailed information on the instrument, methods, and implementation of the study. The technical summaries allow for comparisons across studies regarding specific issues. The preface to the report notes that there are now 5 consecutive years of national data on household food security and that state-level food security prevalence rates for 1996 to 1998 are available. In addition, specific at-risk populations are considered in a growing number of studies, including food stamp or welfare recipients, emergency food assistance recipients, legal immigrants, and general low-income populations. Finally, the locally initiated studies included in this report model the innovative collaborations between various non-profit organizations that make these studies feasible and maximize their impact on advocacy for improved local programs and policies. (KB)