Mo. Rev. Stat. § 379.265

Such company not possessed of assets at least equal to the unearned premium reserve and other liabilities shall make an assessment upon its members liable to assessment to provide for such deficiency, such assessment to be against each such member in proportion to such liability as expressed in his policy; provided, the director may, by written order, relieve the company from an assessment or other proceedings to restore such assets during the time fixed in such order; and provided, that any domestic company which shall be deficient in providing the unearned premium reserve required hereby may, notwithstanding such deficiency, come under this law on the condition that it shall each year thereafter reduce such deficiency at least fifteen percent of the original amount thereof, and in such case it may increase its assessments accordingly.