A civil action is commenced by filing a complaint with
the court.
Rule 3.Commencing an Action
Enacted effective October 1, 2011 · Last verified June 26, 2026
In one sentenceRule 3 fixes the moment a lawsuit begins in Montana: a civil action is commenced by filing a complaint with the court.
Full Text of Rule 3
Plain-English Summary
Rule 3 answers a deceptively important question: when does a lawsuit actually start? In Montana, it starts when you file the complaint with the court — not when the defendant is served.
That timing matters. The filing date is the point used to measure the statute of limitations, so filing on time preserves a claim even if the defendant has not yet been served. Filing also starts the procedural clocks that follow, including the generous three-year window to accomplish service under Rule 4(t).
Frequently Asked Questions
How do I start a lawsuit in Montana?
By filing a complaint with the court. That single act commences the civil action.
Does serving the defendant start the case?
No. Filing the complaint commences the action; service comes afterward under Rule 4, and a plaintiff has up to three years to accomplish it under Rule 4(t).
Why does the filing date matter?
It is the date used for statute-of-limitations purposes and it starts the deadlines that follow, so filing before the limitations period runs preserves the claim.
Source & verification. Reproduced verbatim from the Montana Code Annotated as
published by the State Law Library of Montana and the Montana Legislature. This rule has not been amended since its adoption.
Adopted by the Supreme Court of Montana (AF 07-0157). Last verified June 26, 2026. ·
Official text
Also known as: commencing an actionfiling a complaintcommence