S.D. Codified Laws § 58-17-30.9
For any insurer that chooses to automatically cover any newborn or newly adopted child as a dependent without requiring the notice in § 58-17-30.4 and does not collect or track the demographic information on the dependent child, the insurer shall take reasonable steps to provide adequate notice of the insured's responsibility to advise the insurer when there is no longer any child eligible for dependent coverage. An insurer is considered to have taken reasonable steps if prominent disclosure of this responsibility is included in the policy or certificate, subscriber contract, evidence of coverage, or employee handbook if such are provided to all insureds and also provided to prospective insureds at the time of application for coverage. Upon receipt of a notice that a dependent is no longer eligible, the insurer shall adjust the coverage accordingly and, if applicable, return to the insured any unearned premium. This section applies to any policy or certificate subject to the provisions of chapters 58-17 and 58-18.
SDCL 58-17-30.9