For the purposes of this chapter, the state board of regents and the board of directors of any school district in the state of Iowa may enter into contracts for the laboratory schools to furnish instruction to the pupils of such school district and to train teachers on an agreed basis for tuition and other compensation to be paid by the school district. Such contracts shall be in writing and may extend for any stipulated period not to exceed fifteen years. During the agreed period, such contracts shall be obligatory on both the school district and the state board of regents.
Iowa Code § 265.4