Following news reports that the Federal Bureau of Prisons (BOP) had confined an inmate for 13 months past his correct release date, the Department of Justice (Department) Office of the Inspector General (OIG) initiated an examination of the BOP's process for ensuring federal inmates are released on their correct release dates and the incidences of releases before or after the correct release date due to staff error between 2009 and 2014. We found that of the 461,966 inmate releases between 2009 and 2014, the BOP categorized 157 as untimely due to staff error. We also learned that the BOP classifies a far greater number - 4,183 - as untimely for other reasons.This report contains three case studies profiling inmate releases that were more than 1 year late. The report also makes seven recommendations for the BOP to help reduce untimely releases due to staff error.