Section 10.66 - Reply to answer(a) The Internal Revenue Service may file a reply to the respondent's answer, but unless otherwise ordered by the Administrative Law Judge, no reply to the respondent's answer is required. If a reply is not filed, new matter in the answer is deemed denied.(b)Effective/applicability date. This section is applicable beginning August 2, 2011.T.D. 9527, 76 FR 32309 , June 3, 2011