The Residency Requirement for a Montana Divorce

To file for divorce in Montana, one spouse must have been domiciled in the state, or stationed here as a member of the armed services, for the 90 days before filing. That is the whole residency rule for ending the marriage. Which county you file in, and whether the court can decide parenting for your children, are separate questions with their own tests. This page is part of our Montana Divorce Guide.

The 90-Day Rule

The rule is in the statute that lists what a court must find before entering a decree. The court must find that "one of the parties, at the time the action was commenced, was domiciled in this state" or "was stationed in this state while a member of the armed services," and that "the domicile or military presence has been maintained for 90 days preceding the filing of the action" (MCA § 40-4-104(1)(a)).

Three points follow from the wording:

• One spouse is enough. It can be the spouse who files or the spouse who is served.
• The clock runs backward from filing. The 90 days must already have passed when the petition is filed.
• The petition has to say so. It states each spouse's residence and length of residence in Montana, and that the requirements of § 40-4-104 exist (MCA § 40-4-105(1)(a), (c)).

A petition for legal separation must allege the same requirements (MCA § 40-4-105(1)(c)). A summary dissolutionis available only if "each party has met the requirements of 40-4-104" (MCA § 40-4-130(1)).

What Domicile Means

The dissolution statute says "domiciled" but does not define it. Montana's general rules for determining residence are in MCA § 1-1-215. A residence is the place where a person remains when not called elsewhere for labor or another special or temporary purpose, and to which the person returns in seasons of repose. A person has only one residence, it is not lost until another is gained, and it "can be changed only by the union of act and intent."

In plain terms, time spent in Montana and the intent to make it home both matter. A seasonal stay, a temporary work assignment, or an extended visit raises a real question about whether the 90 days have been met. Whether your facts satisfy the rule is something to review with a lawyer before you file, because a case filed too early can be challenged.

Service Members Stationed in Montana

A service member may keep a legal home in another state while assigned here. The statute accounts for that. Being "stationed in this state while a member of the armed services" for the 90 days before filing satisfies the requirement in place of domicile (MCA § 40-4-104(1)(a)). The wording covers the case where either spouse is the one stationed here, because it applies to "one of the parties."

Military cases raise other issues that are governed partly by federal law. See military divorce in Montana and our military divorce page.

Which County to File In

Dissolution cases are filed in district court. For cases under Title 40, chapter 4, the proper place of trial is "the county in which the petitioner or the respondent has resided during the 90 days preceding the filing of the action" (MCA § 25-2-118(3)). If you live in Missoula County and your spouse lives in Ravalli County, either county meets that description.

If a case is filed in a county that is not the proper one, the court must change the place of trial on motion (MCA § 25-2-201(1)). For how the local court handles family cases, see divorce court in Missoula County.

Children Are a Separate Question

Meeting the 90-day rule lets a Montana court end the marriage. It does not by itself give the court authority over parenting. That is governed by the Uniform Child Custody Jurisdiction and Enforcement Act (UCCJEA), found at Title 40, chapter 7.

Under MCA § 40-7-201(1)(a), a Montana court can make an initial parenting decision if Montana is the child's home state when the case begins, or was the home state within the 6 months before and a parent still lives here. "Home state" means the state where the child lived with a parent for at least 6 consecutive months immediately before the case began, or since birth for a child under 6 months old (MCA § 40-7-103(7)). Other grounds apply only when no state qualifies as the home state or the home state declines to act. The statute also says that physical presence of a child or a parent is neither necessary nor sufficient (MCA § 40-7-201(3)).

The result is that a parent who moved to Montana with a child four months ago may be able to file for dissolution here, while the parenting plan has to be decided in the state the child left. There is a temporary emergency exception when a child is present in Montana and has been abandoned or needs protection from mistreatment or abuse (MCA § 40-7-204). Our page on which state decides custody explains the rules.

The Four Questions Side by Side

The last row matters when a spouse has never lived in Montana. The property and maintenance statutes both refer to a later proceeding after a dissolution "by a court that lacked personal jurisdiction over the absent spouse" (MCA §§ 40-4-202(1), 40-4-203(1)). In other words, the code anticipates that a court may be able to end a marriage without being able to bind an absent spouse on financial issues. Whether that applies to you depends on your spouse's contacts with Montana.

If You Do Not Meet the Rule Yet

If neither spouse has 90 days in Montana, the options are generally to wait until one of you does or to file in a state where one of you already qualifies. Each state sets its own requirement, so check that state's law. If you need protection or support orders before then, ask a lawyer what is available. For the steps once you qualify, see how to file for divorce in Montana and how divorce works in Montana.

This page explains Montana law in general as of the 2025 Montana Code Annotated. It is not legal advice about your specific situation.