Okla. Stat. tit. 70 § 6-106
Boards of education are hereby authorized to contract with and pay all teachers in their respective districts in twelve (12) monthly payments or fractional parts of the fiscal year, to be made on the basis of legal contracts between said board and teachers. Procedures for paying teachers shall be in accordance with any plan approved by the State Department of Education.
The aggregate amount of such salary payments in any fiscal year shall be as agreed upon by the board and the teacher. Under the terms of a contract for a ten-month school year as defined in Section 1-109 of this title and made in keeping with the provisions of this section, no duties shall be expected or required of the teacher in excess of one hundred ninety (190) days; provided, nothing herein shall be construed as prohibiting the making of contracts for school years of more than ten (10) months. Any district adopting this plan of payment may make it applicable to any or all teachers employed therein. Such plan shall be permissive rather than mandatory and may be discontinued at the close of any fiscal year.
All salaries paid in twelve (12) installments pursuant to the provisions of this section shall be for calendar months or fractional parts thereof.
Okla. Stat. tit. 70, § 6-106