Dropping out of high school is related to a number of negative outcomes. For example, the average income of persons ages 18 through 65 who had not completed high school was roughly $20,100 in 2005.1 By comparison, the average income of persons ages 18 through 65 who completed their education with a high school credential, including a General Educational Development (GED) certificate, was nearly $29,700 (U.S. Census Bureau 2006). Dropouts are also less likely to be in the labor force than those with a high school credential or higher and are more likely to be unemployed if they are in the labor force (U.S. Department of Labor 2006). In terms of health, dropouts older than age 24 tend to report being in worse health than adults who are not dropouts, regardless of income (U.S. Department of Education 2004). Dropouts also make up disproportionately higher percentages of the nation's prison and death row inmates. This report builds upon a series of National Center for Education Statistics (NCES) reports on high school dropout and completion rates that began in 1988. It presents estimates of rates in 2005, provides data about trends in dropout and completion rates over the last three decades (1972-2005), and examines the characteristics of high school dropouts and high school completers in 2005. Four rates are presented to provide a broad picture of high school dropouts and completers in the United States, with each contributing unique information: the event dropout rate, the status dropout rate, the status completion rate, and the averaged freshman graduation rate. The following are appended: (1) Technical Notes and Glossary; and (2) Standard Error Tables. (Contains 4 figures, 26 tables, and 22 footnotes.)