A health maintenance organization which provides health care coverage pursuant to an individual or group health maintenance organization contract regulated under this chapter for children of an enrollee shall permit continuation of existing coverage or reenrollment in previously existing coverage for an individual who meets the requirements of section 513B.2, subsection 14, paragraph “a”, “b”, “c”, “d”, or “e”, and who is an unmarried child of an enrollee who so elects, at least through the policy anniversary date on or after the date the child marries, ceases to be a resident of this state, or attains the age of twenty-five years old, whichever occurs first, or so long as the unmarried child maintains full-time status as a student in an accredited institution of postsecondary education.