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 most rates in 2004, provides data about trends in dropout and completion rates over the last three decades (1972-2004), and examines the characteristics of high school dropouts and high school completers in 2004. Four rates are presented to provide a broad picture of high school dropouts and completers in the United States, with each contributing unique information: (1) the event dropout rate; (2) the status dropout rate; (3) the status completion rate; and (4) the averaged freshman graduation rate. Appended are: (1) Technical Notes and Glossary; and (2) Standard Error Tables. (Contains 25 tables, 3 figures, and 25 footnotes.) [For "Dropout Rates in the United States: 2002 and 2003. E.D. TAB," see ED492587.]