After September 1, 1988, no person without a valid Missouri certificate shall:

1. (1) Engage in the practice of teaching or the performance of education duties in grades kindergarten through twelve in any public school in the state;
2. (2) Act as a school administrator in any public school district.

(L. 1963 p. 200 § 9-8, A.L. 1984 H.B. 1457 & 1501, A.L. 2002 S.B. 722, A.L. 2014 H.B. 1298 Revision)

(Source: RSMo 1959 § 168.020)