D.C. Mun. Regs. tit. 16, r. 16-1510
Within fifteen (15) days of service of the petition, respondent shall answer the petition. An answer shall admit or deny each allegation in the petition, and set forth any defense. If the respondent fails to answer the petition within the allocated time, the Office of Adjudication may hold that respondent to have admitted all allegations raised in the petition and may enter an order in favor of the Petitioner.
If the Office of Adjudication holds that all allegations raised in the petition are admitted in accordance with § 1510.1, the respondent may request by motion that the case be reopened to allow the respondent to answer the petition. The motion may only be considered when filed within fifteen (15) days of the date on which the Office of Adjudication holds such allegations as admitted. The Office of Adjudication may grant these motions only under extraordinary circumstances.
Parties, witnesses and other persons may file appropriate motions, including motions to intervene or to join another person to the action.
D.C. Mun. Regs. tit. 16, r. 16-1510