S.D. Codified Laws § 58-17-11
Every individual health insurance policy or contract, except single premium nonrenewable policies or contracts, issued for delivery in South Dakota on or after December 31, 1966, by an insurance company, nonprofit hospital service plan, or medical service corporation, shall have printed thereon or attached thereto a notice stating in substance that the person to whom the policy or contract is issued shall be permitted to return the policy or contract within ten days of its delivery to said purchaser and to have the premium paid refunded if, after examination of the policy or contract, the purchaser is not satisfied with it for any reason. If a policyholder or purchaser pursuant to such notice, returns the policy or contract to the company or association at its home or branch office or to the insurance producer through whom it was purchased, it is void from the beginning and the parties shall be in the same position as if no policy or contract had been issued.
SDCL 58-17-11