Rule 24(c) of the Federal Rules of Criminal Procedure permits the replacement of a regular juror by an alternate juror prior to the time the jury retires to consider its verdict. Once the jury retires, the alternate jurors must be discharged. If a regular juror must be discharged after submission of the case to the jury, Rule 23(b) permits the court, in its discretion, to proceed with the remaining 11 jurors. However, some Federal courts send an alternative to observe the jury's deliberations, while others keep alternate jurors separately sequestered. These judicially improvised procedures violate the plain language of Rule 24(c). In cases involving contact between the alternate and regular jurors, the use of these procedures should constitute reversible error. When postsubmission contact does not take place, however, no possibility exists that the local procedure affected the jury's verdict. In these cases, the verdicts should not be disturbed. 150 footnotes.