This paper provides an overview of the federal sentencing system. For historicalcontext, it first briefly discusses the evolution of federal sentencing during the past fourdecades, including the landmark passage of the Sentencing Reform Act of 1984 (SRA),1 inwhich Congress established a new federal sentencing system based primarily on sentencingguidelines, as well as key Supreme Court decisions concerning the guidelines. It thendescribes the nature of federal sentences today and the process by which such sentencesare imposed. The final parts of this paper address appellate review of sentences; therevocation of offenders' terms of probation and supervised release; the process whereby theUnited States Sentencing Commission (the Commission) amends the guidelines; and theCommission's collection and analysis of sentencing data.