Prisoners may be released to parole by a parole board decision (discretionary release/discretionary parole), according to provisions of a statute (mandatory release/mandatory parole), through other types of post-custody conditional supervision, or as the result of a sentence to a term of supervised release.
In the federal system, a term of supervised release is a sentence to a fixed period of supervision in the community that follows a sentence to a period of incarceration in federal prison, both of which are ordered at the time of sentencing by a federal judge.
Parolees can have a number of different supervision statuses, including active supervision, which means they are required to regularly report to a parole authority in person, by mail, or by telephone.
Some parolees may be on an inactive status, which means they are excluded from regularly reporting, and that could be due to a number of reasons. For instance, some may receive a reduction in supervision, possibly due to compliance or meeting all required conditions before the parole sentence terminates, and therefore may be moved from an active to inactive status.
Other supervision statues include parolees who only have financial conditions remaining, have absconded, or who have active warrants.
Parolees are also typically required to fulfill certain conditions and adhere to specific rules of conduct while in the community. Failure to comply with any of the conditions can result in a return to incarceration.