40 CFR §305.22

1. (a)General. The Claims Official shall file an original and one copy of a written answer to the Request for a Hearing with the Hearing Clerk when he: contests any material fact upon which the Request for a Hearing is based; contends that the amount of money demanded in the Request for a Hearing is inappropriate; or contends that he is entitled to judgment as a matter of law. Any such answer to the Request for a Hearing must be filed with the Hearing Clerk and served on all parties within 15 days after the Presiding Officer has assumed jurisdiction over the case as provided by § 305.4(d).
2. (b)Contents of the answer. The answer shall clearly and directly admit, deny, or explain each of the factual allegations in the Request for a Hearing with regard to which the Claims Official has any knowledge. When the Claims Official has no knowledge of a particular allegation and so states, the allegation is deemed denied. The answer shall also state:
   1. (1)The circumstances or arguments which are alleged to constitute the grounds of defense; and
   2. (2)The facts which the Claims Official intends to place at issue.
3. (c)Failure to admit, deny, or explain. Failure of the Claims Official to admit, deny or explain any material factual allegation contained in the claim constitutes an admission of the allegation.
4. (d)Amendment of the answer. The Claims Official may amend the answer to the Request for a Hearing upon motion granted by the Presiding Officer.