Mont. Code Ann. § 40-5-815

Payment for a medical claim assigned to the department must be to the department. If a medical claim is not assigned to the department and the claim is submitted by a parent or a third-party custodian, payment must be to the health service provider involved. Payment may be to the parent or third-party custodian submitting the claim if there is written evidence of prepayment to the health service provider by that parent or third-party custodian.