S.D. Codified Laws § 61-5A-26
At the end of each calendar quarter, or at the end of any other period as determined by the department, the department shall bill each nonprofit organization, political subdivision, or group of such organizations which has elected to make payments in lieu of contributions for an amount equal to the full amount of regular benefits plus, in the case of a nonprofit organization, one-half of the amount of extended benefits paid during such quarter or other prescribed period that is attributable to service in the employ of such organization or, in the case of a political subdivision, prior to December 31, 1978 one-half of the amount of extended benefits and thereafter the amount of extended benefits paid during such quarter or other prescribed period that is attributable to service in the competent employ of such organization.
SDCL 61-5A-26