42 CFR §498.11

1. (a)A representative appointed and qualified in accordance with § 498.10 may, on behalf of the represented party—
   1. (1)Give and accept any notice or request pertinent to the proceedings set forth in this part;
   2. (2)Present evidence and allegations as to facts and law in any proceedings affecting that party to the same extent as the party; and
   3. (3)Obtain information to the same extent as the party.
2. (b)A notice or request may be sent to the affected party, to the party's representative, or to both. A notice or request sent to the representative has the same force and effect as if it had been sent to the party.