S.D. Codified Laws § 13-28A-2.1

Any agreement to allow the regulation of tuition paid between South Dakota school districts and a bordering state's school districts entered into pursuant to this chapter shall specify the tuition rate to be paid by all local school districts on behalf of students enrolled in the school district of a bordering state. However, no tuition regulation program agreement established pursuant to § 13-28A-1 may specify a rate of tuition that is greater than one hundred ten percent of the per student equivalent as defined in § 13-13-10.1.