Mo. Rev. Stat. § 290.235: On-the-job training periods, use of entry-level workers and apprentices — wages — aggregate limit.

1. Employers may use entry-level workers and federally registered apprentices for on-the-job training periods. The wage rate for on-the-job training workers shall be equal to fifty percent of the applicable wage rate for a journeyman worker under the appropriate occupational title for a specific locality.

2. The combined total of entry-level workers and federally registered apprentices shall not exceed a one-to-one ratio with the number of journeyman workers in any occupational title on a public works project subject to sections 290.210 to 290.340.