42 CFR §426.513

1. (a)Petition for participation. Any person or organization that wishes to participate as amicus curiae must timely file with the Board a petition that concisely states—
   1. (1)The petitioner's interest in the hearing;
   2. (2)Who will represent the petitioner; and
   3. (3)The issues on which the petitioner intends to present argument.
2. (b)The nature of the proposed amicus participation. An amicus curiae is not a party to the hearing but may participate by—
   1. (1)Submitting a written statement of position to the Board before the beginning of the hearing;
   2. (2)Presenting a brief oral statement or other evidence at the hearing, at the point in the proceedings specified by the Board; and
   3. (3)Submitting a brief or a written statement when the parties submit briefs.
3. (c)Service by amicus curiae. Serving copies of any briefs or written statements on all parties.