5 CFR § 1690.12 - Power of attorney.
(a) A participant or beneficiary can appoint an agent to conduct business with the TSP on his or her behalf by using a power of attorney (POA). The agent is called an attorney-in-fact. The TSP must approve a POA before the agent can conduct business with the TSP; however, the TSP will accept a document that was signed by the agent before the TSP approved the POA. The TSP will approve a POA if it meets the following conditions:
(1) The POA must give the agent either general or specific powers, as explained in paragraphs (b) and (c) of this section;
(2) A notary public or other official authorized by law to administer oaths or affirmations must authenticate, attest, acknowledge, or certify the participant's or beneficiary's signature on the POA; and
(3) The POA must be submitted to the TSP recordkeeper for approval.
(b) General power of attorney. A general POA gives an agent unlimited authority to conduct business with the TSP, including the authority to sign any TSP-related document. Additional information regarding general powers of attorney can be accessed at http://www.tsp.gov.
(c) Specific power of attorney. A specific power of attorney gives an agent the authority to conduct specific TSP transactions. A specific POA must expressly describe the authority it grants. Additional information regarding special powers of attorney, as well as a sample form, can be accessed at http://www.tsp.gov.