(a) A group policy or contract of insurance for hospital, surgical, or medical expenses incurred as a result of accident or sickness, including a group contract issued by a group hospital service corporation, that provides coverage under the policy or contract for a child of an insured must, on payment of a premium, provide coverage for any grandchild of the insured if the grandchild is:
(1) unmarried;
(2) younger than 25 years of age; and
(3) a dependent of the insured for federal income tax purposes at the time the application for coverage of the grandchild is made.
(b) Coverage for a grandchild of the insured under this section may not be terminated solely because the covered grandchild is no longer a dependent of the insured for federal income tax purposes.