Mo. Rev. Stat. § 513.510

Such homestead shall be subject to attachment and levy of execution upon all causes of action existing at the time of the acquiring such homestead, except as otherwise provided in sections 513.475 to 513.530; and for this purpose such time shall be the date of the filing in the proper office for the records of deeds, the deed of such homestead, when the party holds title under a deed, but when he holds title by descent or devise, from the time he becomes invested with the title thereto; and in case of existing estates, such homestead shall not be subject to attachment or levy of execution upon any liability hereafter created.