Mo. Rev. Stat. § 461.043: Beneficiary designation designating a trustee under trust not invalid because trust is amendable or revocable — trust that is revoked, terminated or does not exist at death of owner, effect.

1. A beneficiary designation designating a trustee under a trust established or to be established by the owner or some other person, including a funded or unfunded trust, shall not be invalid because the trust is amendable or revocable or both or because the trust was amended after the designation.

2. Unless a beneficiary designation provides otherwise, a trust that was revoked or terminated before the death of the owner shall be deemed not to have survived the owner.

3. Unless a beneficiary designation provides otherwise, a legal entity or trust that does not exist or come into existence at the time of the owner's death shall be deemed not to have survived the owner.