(1) No provision of this chapter shall be deemed to prohibit an insurer from issuing a health insurance policy as, or including in a policy a provision providing for, excess insurance; that is, to the effect that the insurer's liability for benefits payable on account of expense incurred for any hospitalization, medical, surgical, and other services resulting from covered sickness or injury of the insured shall be limited to that part of that expense, if any, which is in excess of all benefits payable on account thereof by the same insurer under any other policy or policies covering the same insured and by all other insurers and service organizations by whom benefits are payable as to the same such expense.