Mont. Code Ann. § 50-5-1307

The attending health care provider of a patient for whom a lay or medical proxy decisionmaker has been named shall reexamine the patient and determine whether the patient has regained decisional capacity if the patient or an interested person, guardian, attending health care provider, or the lay or medical proxy decisionmaker believes the patient has regained decisional capacity. The attending health care provider shall enter the determination and the basis for the determination into the patient's medical record and shall notify the patient, the lay or medical proxy decisionmaker, and the person who requested the redetermination of decisional capacity, if the request was made by someone other than the patient or proxy decisionmaker.