SDCL § 25-8-5: Custodian's recovery of support from noncustodian--Period support recoverable.

The custodian may recover support for a period of three years before the date of application with any Title IV-D agency, the date of filing with a court of competent jurisdiction, or the date of a written demand served personally or by registered or certified mail, return receipt requested, upon the noncustodial parent at the noncustodial parent's last known address, whichever occurs earlier.