In 2007, after years of dissatisfaction with the 100-to-1 disparity between crack cocaine and powder cocaine, the U.S. Sentencing Commission amended the U.S. Sentencing Guidelines, reducing by two levels the base offense level assigned to threshold quantities of crack cocaine. The amendment was subsequently made retroactive, which required the federal courts to process approximately 20,000 prisoner motions for sentence reduction. Using data collected from a case study of one particular district as well as a survey of representatives from the 94 federal judicial districts, this study examines the process of "crack retroactivity" implementation. The authors found that court communities varied greatly with respect to their organizational arrangements, procedures, and motivations. Although U.S. Probation and Pretrial Services played an important role in every district, how and why districts organized to respond to crack retroactivity varied. The study findings also indicate that sentencing procedures may be another mechanism through which location affects sentencing outcomes.