Mo. Rev. Stat. § 376.680
Subject to the terms of the policy relating to assignment of incidents of ownership thereunder, a person whose life is insured under a policy of group life insurance may assign any or all incidents of ownership granted him under such policy, including but not limited to any right to designate a beneficiary, to have an individual policy issued to him, and to pay premiums. Any assignment by the insured, made either before or after September 28, 1971, shall be valid for the purpose of vesting in the assignee in accordance with any provisions included therein as to the time at which it is to be effective, all of such incidents of ownership so assigned, but without prejudice to the insurer on account of any payment it may make or individual policy it may issue without notice of the assignment.
§ 376.680, RSMo