Mo. Rev. Stat. § 377.010

Every contract whereby a benefit is to accrue to a person or persons named therein, upon the death or physical disability of a person also named therein, the payment of which said benefit is in any manner or degree dependent upon the collection of an assessment upon persons holding similar contracts, shall be deemed a contract of insurance upon the assessment plan, and the business involving the issuance of such contracts shall be carried on in this state only by duly organized corporations which shall be subject to the provisions and requirements of sections 377.010 to 377.190.