S.D. Codified Laws § 3-12C-214
If any change or error in the records of the system or any participating unit results in any person receiving from the system less than the person would have been entitled to receive had the records been correct, the executive director shall correct the error and, as far as practicable, shall adjust the payment to provide the person the amount to which the person is correctly entitled.
If any change or error in the records of the system or any participating unit results in any person receiving from the system more than the person would have been entitled to receive had the records been correct, the executive director shall correct the error and, as far as practicable, shall recover the overpayment to reflect the amount to which the person is correctly entitled. The board shall promulgate rules, pursuant to chapter 1-26, concerning the methods by which an overpayment shall be repaid, including an actuarial equivalent. However, the recovery of an overpayment is limited to the amount attributable to any error that occurred during the six-year period immediately before the discovery of the error. This limitation does not apply in the case of fraud, intentional misrepresentation, material omission, or other fault on the part of a member or beneficiary.
SDCL 3-12C-214