49 C.F.R. § 31.9 – Answer.

(a) The defendant may request a hearing by serving an answer on the reviewing official within 30 days of service of the complaint. Service of an answer shall be made by delivering a copy to the reviewing official or by placing a copy in the United States mail, postage prepaid and addressed to the reviewing official. Service of an answer is complete upon such delivery or mailing. An answer shall be deemed to be a request for hearing.
(b) In the answer, the defendant—
1. (1) Shall admit or deny each of the allegations of liability made in the complaint;
2. (2) Shall state any defense on which the defendant intends to rely;
3. (3) May state any reasons why the defendant contends that the penalties and assessments should be less than the statutory maximum; and
4. (4) Shall state the name, address, and telephone number of the person authorized by the defendant to act as defendant's representative, if any.
(c) If the defendant is unable to file an answer meeting the requirements of paragraph (b) of this section within the time provided, the defendant may, before the expiration of 30 days from service of the complaint, serve on the reviewing official a general answer denying liability and requesting a hearing, and a request for an extension of time within which to serve an answer meeting the requirements of paragraph (b) of this section. The reviewing official shall file promptly the complaint, the general answer denying liability, and the request for an extension of time as provided in § 31.11. For good cause shown, the ALJ may grant the defendant up to 30 additional days from the original due date within which to serve an answer meeting the requirements of paragraph (b) of this section.