4 C.F.R. § 28.63

(a) When there is a hearing, the record shall be closed at the conclusion of the hearing. However, when the administrative judge allows the parties to submit argument, briefs or documents previously identified for introduction into evidence, the record shall be left open for such time as the administrative judge grants for that purpose.

(b) Once the record is closed, no additional evidence or argument shall be accepted into the record except upon a showing that new and material evidence has become available which was not available despite due diligence prior to the closing of the record. However, the administrative judge shall make part of the record any motions for attorney fees, any supporting documentation, and determinations thereon, and any approved correction to the transcript.