MT 4th Judicial District (Missoula and Mineral Counties): Montana 4th Judicial District C…

What the rule requires

Local Rule 3(G) of the Montana 4th Judicial District (Missoula and Mineral Counties) is the most detailed of Montana’s three district-level AI disclosure rules. It imposes a four-element disclosure, an absence-of-AI presumption, and an explicit Rule 11 sanctions hook.

1. Four-element disclosure. When a party uses generative AI in preparing a filed pleading or document, four items must appear in the disclosure:
   • that generative artificial intelligence was used;
   • the specific tool the party used;
   • how the party used the tool in preparing the document; and
   • certification that the party has checked the accuracy of any AI-drafted or AI-assisted portion, “including all factual and procedural background, citations, and legal authority.”
2. Absence-of-AI presumption. Under the rule, “the court presumes that a party who files a document that does not contain this certification certifies that no part of the document was prepared using generative artificial intelligence.” Skipping the certification is itself a representation under the rule, not a neutral omission.
3. Responsibility under Rule 11 and professional conduct rules. The attorney or pro se litigant is responsible for contents “under Montana Rule of Civil Procedure 11 and applicable rules of professional conduct and attorney discipline.”
4. Sanctions framework. Per the rule, “if the court has good reason to suspect that a filing has relied on generative artificial intelligence in violation of this rule, and the party has not reasonably dispelled the court’s concerns, such violation may result in the imposition of appropriate sanctions under Montana Rule of Civil Procedure 11, including the possibility of dismissal of the responsible party’s case, document, or pleading without prejudice.”
5. Definition explicitly broad. Generative AI is defined as a computer tool that generates new content in response to a prompt by learning from a large reference database. The definition expressly reaches tools “substantially similar… but differ in some unique way.” Its breadth is intended to forestall hair-splitting about whether a particular tool is or is not “generative AI.”

Context

The February 2026 Missoula public defender incident illustrated how the rule operates in practice. A criminal defense motion was filed without the Rule 3(G) certification but contained text that read like a generative AI prompt response (“Below is concise motion language you can drop into a ‘Motion to Admit Mental-Disease Evidence…’”). On February 17, 2026, the county attorney moved to strike, citing Rule 3(G) noncompliance. The defending attorney moved to strike her own filing and refiled. Two features of the incident map directly to the rule’s design. First, the absence-of-AI presumption was implicitly violated: the unsigned representation that no AI was used was contradicted by the document’s text. Second, Rule 11 was the operative sanctions pathway.

Practitioner workflow

For 4th Judicial District matters, AI disclosure when applicable should appear on the face of the filing. It must include all four elements: that generative AI was used, the specific tool, the manner of use, and the accuracy certification reaching factual background, procedural background, citations, and legal authority. Firms practicing in both Missoula and Billings may wish to use a single disclosure block built on the Rule 3(G) format, provided it also certifies that every citation to law or to the record in the whole filing has been verified, which 13th Judicial District Rule 35 requires even for portions not drafted with AI. In the 15th Judicial District, a filing prepared in whole or in part with an AI service or chatbot also needs that district’s disclosure and Rule 11 certification (Rule 3(N)).

At intake, the absence-of-AI presumption deserves attention. Under the rule, filing a document without the certification is an affirmative representation that no part of the document was AI-prepared. A firm whose drafting workflow uses AI even for early-stage research or outlining should treat that as a Rule 3(G) trigger and disclose conservatively rather than rely on the absence-of-AI presumption.

Scope

Missoula and Mineral Counties only (Montana 4th Judicial District). No statewide rule has been adopted by the Montana Supreme Court. The 13th (Yellowstone) and 15th (Daniels, Sheridan and Roosevelt Counties) Judicial Districts have their own AI disclosure rules. For federal Montana matters, see Judge Molloy’s pro hac vice condition (D. Mont., in use since at least June 22, 2023). It prohibits out-of-state counsel admitted before him from using generative AI drafting programs.

Primary source

4th Judicial District Local Rules (PDF, see Rule 3(G) at page 7): https://courts.mt.gov/external/dcourt/dc_rules/4th.pdf