42 CFR §498.10

1. (a)An affected party may appoint as its representative anyone not disqualified or suspended from acting as a representative in proceedings before the Secretary or otherwise prohibited by law.
2. (b)If the representative appointed is not an attorney, the party must file written notice of the appointment with CMS, the ALJ, or the Departmental Appeals Board.
3. (c)If the representative appointed is an attorney, the attorney's statement that he or she has the authority to represent the party is sufficient.