Mo. Rev. Stat. § 104.1093
Notwithstanding any provision of law to the contrary, any employee, beneficiary, or retiree pursuant to sections 104.010 to 104.1093 may designate an agent who shall have the same authority as an agent pursuant to a durable power of attorney pursuant to sections 404.700 to 404.737, RSMo, with regard to the application for and receipt of an annuity or any other benefits. The authority of such agent may be revoked at any time by such employee, beneficiary or retiree. The authority of such agent shall not terminate if such employee, beneficiary or retiree becomes disabled or incapacitated.
(L. 1999 S.B. 308 & 314)