Mo. Rev. Stat. § 162.626
There is hereby established in the metropolitan school district a pilot program of multiyear teacher-student groupings. The program shall be implemented in no fewer than ten schools in the district and shall be implemented for no less than five consecutive years in each of such schools and in at least six classrooms in each of such schools. Pupil-teacher ratios in such classrooms shall not exceed twenty-five to one. The program shall seek to improve student learning by providing a long-term relationship between the student and a particular teacher. The board shall develop a plan for grade-level groups throughout which participating classes shall maintain the same group of students with the same teacher for multiyear periods. The grade-level groups shall include at least two grade levels and shall not exceed four grade levels in the same group. The plan shall provide for voluntary participation by students. The board shall establish a policy and a procedure to review and act upon requests by a student or the parent of a student that the student be transferred to a different class with a different teacher. All policies and plans established by the board pursuant to this section* shall be subject to review and approval of the state board of education.
§ 162.626, RSMo