If a group disability insurance contract or blanket disability insurance contract provides for or offers reimbursement for any service which is within the lawful scope of the practice of a chiropractor holding a certificate or license issued by the state in which the services are rendered, a subscriber covered under such contract may select either a physician or chiropractor to provide the examination, care or treatment for which the subscriber is eligible and which falls within the scope of practice of the chiropractor or physician. Reimbursement for the cost of the service may be made directly to the person licensed or certified pursuant to title 32, chapter 8 or 13 or to the subscriber if the cost of the service has not been reimbursed to another provider or health care institution.