Mandatory minimum sentences enacted by the U.S. Congress require judges to impose prison terms of not less than the number of years specified by Congress as punishment for certain offenses. These sentences are applied most often in cases of illegal drug trafficking and depend on the amount of the substance involved. The prison terms are arbitrarily set by Congress, often apparently as a response to a perceived public call to be "tough on crime." Mandatory minimums allow no freedom of choice to the sentencing judge, although the Federal sentencing guidelines permit, but severely limit, the exercise of judicial discretion in sentencing. Until mandatory minimums are repealed, changes in the guidelines can provide only limited improvements in sentencing procedures. In addition to recommending the repeal of mandatory sentences, the Federal Courts Study Committee also urged that serious consideration be given to proposals that the Federal sentencing guidelines become general standards and that they permit consideration of an offender's age and personal history as well as criminal history. Some defects identified in the guidelines are an increase in the time required for pleas and sentencing, undue rigidity in fashioning the sentence, reduction of incentives to enter guilty pleas, limitations on the concessions prosecutors can offer in plea bargaining, a shift of sentencing discretion from the courts to the prosecutors, and distortion of the role of probation officers. 25 footnotes