(1) An applicant, parent or guardian must have the opportunity to choose a primary care provider to the extent possible and medically appropriate from the providers available at the time of enrollment. The insurer may assign an enrollee to a primary care provider if an enrollee, parent or guardian fails to choose one after being notified to do so. The assignment must be appropriate to the enrollees age, gender and residence. The enrollee may change primary care providers once annually without good cause as defined in Montana insurance law and rules.