Mo. Rev. Stat. § 377.280: Surrender values.

Any corporation, company or association transacting business under the provisions of sections 377.200 to 377.460, may allow cash values on its policies or the equivalent of the cash value in extended or paid-up insurance to the extent of the unused portion of the emergency fund equitably apportioned at the dates of surrender, and may allow fixed cash values on its limited payment or investment policies, or the equivalent of the cash value in extended or paid-up insurance; provided, the amount to be set apart for such fixed cash value or its equivalent is plainly stated in the policy; and provided further, that such fixed cash value shall not be in excess of the portion of the premium with interest accretions thereon collected for that purpose.