S.D. Codified Laws § 3-12C-217.1

If a qualified domestic relations order provides that a member's former spouse must be treated as a beneficiary for any payment pursuant to § 3-12C-409, the provision must supersede any contrary beneficiary designation by the member. The provision of the qualified domestic relations order and the member's beneficiary designation must be administered in a manner that gives full effect to the order and both proportional and equitable effect to the member's designation of any beneficiary.