Rule 11 contains a safe harbor, which requires the party seeking sanctions to give the responding party 21 days to remove or correct the challenged pleading. Failure to give this notice is fatal to the motion for sanctions. Thus, a party cannot wait until after the judgment is entered and then move for sanctions.
The Church of Scientology attempted to renew a motion for sanctions filed in 2009 to no avail.
“A party cannot move for sanctions after a judgment unless the opposing party enjoys the twenty-one day safe harbor before the judgment:
Service of a sanctions motion after the district court has  entered judgment prevents giving effect to the safe harbor provision or the policies and procedural protections it provides . . . . If the motion for sanctions is served after  a final order has been issued, the motion will be rejected because the party who allegedly violated [Rule 11] no longer is able to withdraw the improper papers or otherwise rectify the alleged offense and thus has not been given the full protection mandated by [Rule 11’s] safe harbor provision.
5A Wright & Miller, et al., Federal Practice & Procedure § 1337.2 (3d ed. 2011); Roth v. Green, 466 F.3d 1179, 1193 (10th Cir. 2006); Brickwood Contractors, Inc. v. Datanet Eng’g, Inc., 369 F.3d 385, 389 (4th Cir. 2004); Ridder v. City of Springfield, 109 F.3d 288, 297 (6th Cir. 1997) (“a party cannot wait until after summary judgment to move for sanctions underRule 11“); Advisory Committee’s Note on 1993 Amendments to Fed.R.Civ.P. 11 (“Given the `safe harbor’ provisions . . . a party cannot delay serving its Rule 11 motion until conclusion of the case”); 2 Moore, et al., Moore’s Federal Practice § 11.22[c] (3d ed. 2011) (“A party must serve its Rule 11 motion before the court has ruled on the pleading, and thus before the conclusion of the case. Otherwise, the purpose of the `safe harbor’ provision would be nullified”); 61A Am. Jur. 2d Pleading § 581 (“the [Rule 11] motion must be served 21 or more days prior to final judgment”); Georgene M. Vairo, Rule 11 Sanctions: Case Law, Perspectives and Preventive Measures, 96-97 (3d ed. 2004) (calling the submission of a post-judgment Rule 11 motion “a fruitless exercise” because “the court must deny the  motion for failure to comply with the Rule 11(c) procedure”); see also Peer v. Lewis, 606 F.3d 1306, 1313 (11th Cir. 2010); In re Walker, 532 F.3d 1304, 1308 (11th Cir. 2008).”
Edward X. Clinton, Jr.