Mo. Rev. Stat. § 171.121
If any district in this state has an average daily attendance of less than fifteen pupils as shown by the records of the last previous school year, the state board of education, after investigation that convinces it that it would be to the best interests of all concerned, shall require the board to provide for the tuition and transportation of the pupils of the district to other public schools. Separate records of the attendance of pupils from the closed district shall be kept and the district shall receive the same apportionment under section 163.031 as it would have received otherwise. For the first year after the closing of a district, apportionment shall be made under section 163.031 to the closed district on the basis of the average daily attendance of the preceding year and shall be paid by the closed district to the districts receiving its pupils in proportion to the number of pupils received by each.
§ 171.121, RSMo
Effective 7/1/2006