45 CFR § 99.5
Filing and service of papers
April 14, 2021
(a) An original and two copies of all papers in the proceedings shall be filed with the presiding officer. For exhibits and transcripts of testimony, only the originals need be filed.
(b) All papers in the proceedings shall be served on all parties by personal delivery or by certified mail. Service on the party's designated attorney will be deemed service on the party.