S.D. Codified Laws § 25-7A-22
If the support order was entered in this state and this state maintains continuing exclusive jurisdiction over the support order pursuant to chapter 25-9C, or if the support order was registered in this state and the requirements of § 25-9C-611 or 25-9C-613 are satisfied, an obligor, an obligee, or the assignee may file a petition, on forms prescribed by the department, to increase or decrease child support. For any support order entered or modified after July 1, 1997:
If a petition is filed, the secretary of social services shall file the petition in the office of the clerk of the circuit court where the original order for support is filed. Any response shall also be provided to the petitioning party. The matter shall be set for hearing before a referee who is a member in good standing of the State Bar Association and is appointed by the court, pursuant to statute, and after due notice to all parties by first class mail. The referee shall make a report to the court, recommending the amount of the monthly support obligation of the parent and for medical support.
The referee shall file the report with the court and cause copies thereof to be served by mailing to the parties and the secretary. Any party shall have ten days from the date of service of the report in which to file objections to the report. If a party files an objection, the other party shall have an additional five days from the date of service of the objections to file additional objections. If no objection is filed, the circuit court may thereafter, and without further notice, enter its order. If any objection is filed, the circuit court shall fix a date for hearing on the report, the hearing to be solely on the record established before the referee. The circuit court may thereafter adopt the referee's report, or may modify it, or may reject and remand it with instructions or for further hearing. The secretary shall serve the parent the court's order by certified mail, return receipt requested, at the parent's last known address, and shall file proof of service.
If the circuit court's order modifies the referee's report and no hearing was held before the circuit court before entry of its order, any party has ten days from the date of service of the order in which to file an objection to that modification. If an objection is filed, the circuit court shall fix a date for hearing on the objection and after the hearing shall enter its order. The secretary shall serve the order by certified mail, return receipt requested, at the parent's last known address, and shall file proof of service.
SDCL 25-7A-22