MO Rev Stat § 404.590 (2021)
2021 Missouri Revised Statutes|Title XXVI - Trade and Commerce|Chapter 404 - Transfers to Minors — Personal Custodian and Durable Power of Attorney|Section 404.590 - Successor custodian designation on renunciation, resignation, death, incapacity or removal of custodian.

Effective - 28 Aug 1989   404.590. Successor custodian designation on renunciation, resignation, death, incapacity or removal of custodian. — 1. A person designated as a personal custodian may decline to serve by delivering a written renunciation to the person who made the designation or to the transferor or the transferor's legal representative. If at the time of the transfer there is no substitute personal custodian who is able and willing to serve as custodian, the person who made the designation, a person with a power from the donor to designate a personal custodian, the transferor or the transferor's legal representative shall designate a substitute personal custodian.  2. A nonincapacitated beneficiary may revocably designate, or grant to another person a general or limited power to revocably designate, at any time one or more successor personal custodians by executing and dating an instrument of designation before a subscribing witness other than a successor personal custodian. If the beneficiary does not designate a successor personal custodian or is incapacitated, the personal custodian may revocably designate at any time one or more successor personal custodians in a will or by executing and dating an instrument of designation before a subscribing witness other than a successor personal custodian. If the instrument of designation does not contain or is not accompanied by the personal custodian's resignation, the designation of a successor does not take effect until the personal custodian resigns, dies, becomes incapacitated or is removed. Successor personal custodians serve in the order named in the event a prior named personal custodian declines or is not qualified to serve as personal custodian, or is deceased or incapacitated.  3. A personal custodian may resign at any time by delivering written notice to the beneficiary and the successor personal custodian and delivering the custodial property and records of the personal custodianship to the beneficiary, if not incapacitated, or to the successor personal custodian.  4. If the personal custodian dies or becomes incapacitated, the personal custodian's legal representative shall deliver the custodial property to a beneficiary who is not incapacitated or to a successor personal custodian. If no successor personal custodian has been effectively designated and if the beneficiary is incapacitated, the personal custodian's legal representative shall designate as successor personal custodian any adult person or financial institution in the manner provided in subsection 2 of this section and deliver the custodial property to the successor personal custodian.  5. The designation of a successor personal custodian by a personal custodian or the personal custodian's legal representative may be included in the instrument placing custodial property into the name of the successor personal custodian.  6. If the personal custodian or the personal custodian's legal representative does not timely designate a successor personal custodian for an incapacitated beneficiary, the legal representative of an incapacitated beneficiary, an adult member of the incapacitated beneficiary's family or any person interested in the welfare of the beneficiary, may petition the court to designate a successor personal custodian.  7. A successor personal custodian shall hold the custodial property in the manner prescribed in section 404.540 and need not indicate the custodial capacity as a successor personal custodian.  8. A personal custodian who resigns, or the legal representative of a deceased or incapacitated personal custodian, as soon as practicable, shall do all things within that person's lawful power to put each item of the custodial property and the records of the personal custodianship in the possession and control of the beneficiary or of a successor personal custodian.  9. The beneficiary, the beneficiary's legal representative, an adult member of an incapacitated beneficiary's family, a successor personal custodian or any person interested in the welfare of the beneficiary, for good cause shown, may petition the court to remove the personal custodian, to designate a successor personal custodian, to require the personal custodian to give bond and to order delivery of the custodial property and records of the custodianship to the beneficiary, a successor personal custodian or the beneficiary's legal representative. ­­-------- (L. 1986 S.B. 651 § 8, A.L. 1989 H.B. 145)