S.D. Codified Laws § 58-38-11.4
No accident or health insurance policy providing coverage of hospital or medical expense which in addition to covering the insured also provides coverage to the spouse of the insured shall be issued without a provision that provides that upon eligibility for medicare or social security disability benefits by one spouse the other spouse shall be entitled to have issued to him or her, without evidence of insurability, upon application to the company within sixty days following the eligibility, and upon payment of the appropriate premium, an individual policy of accident or health insurance. Such policy shall provide the coverage then being issued by the insurer which is most nearly similar to the existing coverages. This obligation can be met by continuation of coverage for spouse under existing policy at the appropriate premium. Any and all probationary or waiting periods set forth in such policy shall be considered as being met to the extent coverage was in force under the prior policy.
SDCL 58-38-11.4