28 CFR 68.9 - Responsive pleadings
(b) Default. Failure of the respondent to file an answer within the time provided may be deemed to constitute a waiver of his or her right to appear and contest the allegations of the complaint. The Administrative Law Judge may enter a judgment by default.
(c) Answer. Any respondent contesting any material fact alleged in a complaint, or contending that the amount of a proposed penalty or award is excessive or inappropriate, or contending that he or she is entitled to judgment as a matter of law, shall file an answer in writing. The answer shall include:
(1) A statement that the respondent admits, denies, or does not have and is unable to obtain sufficient information to admit or deny each allegation; a statement of lack of information shall have the effect of a denial (any allegation not expressly denied shall be deemed to be admitted); and
(2) A statement of the facts supporting each affirmative defense.
(d) Reply. Complainants may file a reply responding to each affirmative defense asserted.
(e) Amendments and supplemental pleadings. If a determination of a controversy on the merits will be facilitated thereby, the Administrative Law Judge may, upon such conditions as are necessary to avoid prejudicing the public interest and the rights of the parties, allow appropriate amendments to complaints and other pleadings at any time prior to the issuance of the Administrative Law Judge's final order based on the complaint. When issues not raised by the pleadings are reasonably within the scope of the original complaint and are tried by express or implied consent of the parties, they shall be treated in all respects as if they had been raised in the pleadings, and such amendments may be made as necessary to make the pleading conform to the evidence. The Administrative Law Judge may, upon reasonable notice and such terms as are just, permit supplemental pleadings setting forth transactions, occurrences, or events that have occurred or new law promulgated since the date of the pleadings and which are relevant to any of the issues involved.