Mont. Code § 50-16-531
A health care provider who discloses health care information within the possession of the provider, including health care information from another provider, is immune from any civil cause of action by the patient or the patient's heirs or successors in interest that is based upon delivery to the patient or the patient's designee of health care information concerning the patient that is contained in the health care provider's patient file if the information is disclosed in accordance with a written authorization using the following language:
"All health care information in your possession, whether generated by you or by any other source, may be released to me or to ...............(named person) for ...............(purpose of the disclosure). This release is subject to revocation at any time. The revocation is effective from the time it is communicated to the health care provider. If not revoked, the release terminates in accordance with 50-16-527.
...............................
(Signature of patient)"
§ 50-16-531, MCA