Structures that limit postsentencing discretion include parole guidelines, court specification of minimum and maximum terms of incarceration, fixed sentencing, and determinate sentencing. Structures that limit judicial discretion include statutory limits, mandatory sentences, presumptive sentencing, and sentencing guidelines. Depending on the detailed provisions involved, determinate sentencing combined with sentencing guidelines can either concentrate the determinations of sentence length in the court or shift control over sentence length to police and prosecutors. Sentencing guidelines can be applied in a way that makes judges accountable for individual sentence length decisions. They can make disparity and discrimination more clearly defined and more easily monitored. These approaches can also make it easier to forecast prison populations. These systems need to have formal feedback mechanisms, however, because the minimization of discretion results in the loss of ability to adjust informally to changes in crime patterns, system resources, or presentence processing. Data tables, footnotes, a list of five suggested readings, detailed summaries of sentencing reforms in several States, and an appendix presenting State-by-State summaries of sentencing practices are supplied.