Missouri Revised Statutes Title XXXI. Trusts and Estates of Decedents and Persons Under Disability § 461.035. Agents may not make, revoke or change beneficiary unless document establishes agent's right or court order authorizes--authorized withdrawals may extinguish beneficiary's right to transfer

1. An attorney in fact, custodian, conservator or other agent may not make, revoke or change a beneficiary designation unless the document establishing the agent's right to act, or a court order, expressly authorizes such action and such action complies with the terms of the governing instrument, the rules of the transferring entity and applicable law.

2. This section shall not prohibit the authorized withdrawal, sale, pledge or other present transfer of the property by an attorney in fact, custodian, conservator or other agent notwithstanding the fact that the effect of the transaction may be to extinguish a beneficiary's right to receive a transfer of the property at the death of the owner.