S.D. Codified Laws § 58-16-53
Each group policy, contract, or certificate subject to the provisions of §§ 58-16-49 to 58-16-54, inclusive, issued on or after July 1, 2009, or under which the level of benefits is altered, modified, or amended on or after July 1, 2009, shall provide a reasonable provision for extension of benefits in the event of total disability at the date of discontinuance of the group policy, contract, or certificate as required by this section.
In the case of a group life plan that contains a disability benefit extension of any type, including premium waiver extension, extended death benefit in event of total disability, or payment of income for a specified period during total disability, the discontinuance of the group policy, contract, or certificate may not operate to terminate the extension.
Any applicable extension of benefits or accrued liability shall be described in any policy or contract involved as well as in group insurance certificates. The benefits payable during any period of extension of benefits or accrued liability may be subject to the policy's, contract's, or certificate's regular benefit limits, such as benefits ceasing at exhaustion of a benefit period or of maximum benefits.
SDCL 58-16-53