SDCL § 58-17-2: Persons covered by policy.

A policy of health insurance shall purport to insure only one person, except that a policy may insure, originally or by subsequent amendment, upon the application of an adult member of a family, who shall be deemed the policyholder, any two or more eligible members of that family, including husband, wife, dependent children, or any children under a specified age which shall not exceed nineteen years and any other person dependent upon the policyholder or any other person related to and resident in the household of the insured.