Mont. Code Ann. § 26-1-805

Except as provided in Rule 35, Montana Rules of Civil Procedure, a licensed physician, surgeon, or dentist may not, without the consent of the patient, be examined in a civil action as to any information acquired in attending the patient that was necessary to enable the physician, surgeon, or dentist to prescribe or act for the patient. A communication described in 45-9-104 (7) is not a privileged communication.