533US2 Unit: $U87 [10-21-02 18:35:10] PAGES PGT: OPIN Cite as: 533 U. S. 678 (2001) 701 Opinion of the Court the occasions when courts will need to make them, we think it practically necessary to recognize some presumptively reasonable period of detention. We have adopted similar presumptions in other contexts to guide lower court determinations. See Cheff v. Schnackenberg, 384 U. S. 373, 379–380 (1966) (plurality opinion) (adopting rule, based on definition of “petty offense” in United States Code, that right to jury trial extends to all cases in which sentence of six months or greater is imposed); County of Riverside v. McLaughlin, 500 U. S. 44, 56–58 (1991) (O’Connor, J.) (adopting presumption, based on lower court estimate of time needed to process arrestee, that 48-hour delay in probable-cause hearing after arrest is reasonable, hence constitutionally permissible). While an argument can be made for confining any presumption to 90 days, we doubt that when Congress shortened the removal period to 90 days in 1996 it believed that all reasonably foreseeable removals could be accomplished in that time. We do have reason to believe, however, that Congress previously doubted the constitutionality of detention for more than six months. See Juris. Statement in United States v. Witkovich, O. T. 1956, No. 295, pp. 8–9. Consequently, for the sake of uniform administration in the federal courts, we recognize that period. After this 6month period, once the alien provides good reason to believe that there is no significant likelihood of removal in the reasonably foreseeable future, the Government must respond with evidence sufficient to rebut that showing. And for detention to remain reasonable, as the period of prior postremoval confinement grows, what counts as the “reasonably foreseeable future” conversely would have to shrink. This 6-month presumption, of course, does not mean that every alien not removed must be released after six months. To the contrary, an alien may be held in confinement until it has been determined that there is no significant likelihood of removal in the reasonably foreseeable future.