S.D. Codified Laws § 58-12-20
Each clean claim shall be paid to the person entitled thereto, denied, or settled within thirty calendar days after receipt by the carrier if submitted electronically and within forty-five calendar days after receipt by the carrier and if the claim is payable under the plan. If the resolution of an otherwise clean claim requires additional information, the carrier shall, within thirty calendar days after receipt of the claim, give the provider, policyholder, insured, or patient, as appropriate, a full explanation of what additional information is needed in order to determine eligibility or adjudicate the claim. The person receiving a request for additional information shall submit all additional information requested by the carrier within thirty calendar days after receipt of such request.
SDCL 58-12-20