Mo. Rev. Stat. § 474.130
Current with changes from the 2023 Legislative Session
When any deed, conveyance, assurance, agreement or contract in lieu of the inheritance or other statutory rights of a spouse, through any default, fails to be a legal bar to such rights and the surviving spouse demands his inheritance and statutory rights, then the estate and interest so conveyed to the surviving spouse ceases and determines.
§ 474.130, RSMo
RSMo 1939 § 336, A.L. 1955 p. 385 § 249