In 1984, the Sentencing Reform Act established the independent United States Sentencing Commission (USSC) and charged it with developing Federal Sentencing Guidelines in order to avoid unwarranted sentencing disparities among similarly situated defendants. In certain cases, judges may impose a sentence that departs downward from the established guidelines or falls below the mandatory minimum; this report discusses such downward departures for Federal drug offenses. Data were obtained from the USSC’s sentencing database for fiscal years 1999 through 2001; data were collected regarding sentences departing downward due to prosecutor’s substantial assistance motion; sentences departing downward for other reasons; and sentences that fell below the applicable mandatory minimum. The USSC’s data on offender and offense characteristics were used to control for major differences among circuits and districts. Results indicate that of the 175,245 sentences imposed by Federal judges that were subject to the Federal Sentencing Guidelines, 64 percent of all Federal criminal sentences and 56 percent of all Federal drug sentences were within applicable guideline ranges. Of the sentences that departed downwards, 18 percent were due to prosecutors’ substantial assistance motions and 17 percent were due to other reasons. Of the Federal drug sentences that departed downward, 28 percent were due to prosecutors’ substantial assistance motions and 16 percent were due to other reasons. Federal drug sentences were imposed in a total of 68,670 cases during fiscal years 1999 through 2001; of these, 52 percent fell below the applicable mandatory minimum. Of these Federal drug sentences that fell below the mandatory minimum, 26 percent were due to substantial assistance, while another 26 percent were due to other reasons. Major variations were noted across the 12 judicial circuits and 94 districts. Empirical data on factors influencing sentencing were not available, thus an analysis of this variation among circuits and districts was not possible. Finally, the report offers recommendations for improving USSC data on Federal drug sentences, including the improvement in the collection and recording of sentencing information and the refinement of the category of “other downward departures.” Tables, figures, appendix