✓ Verified September 2026
To contest a will in Montana, you file in the probate court within a fixed window and prove one of a short list of legal grounds. This guide gives the Montana answer in plain English, and it starts with the deadline, because that is the fact that ends more cases than any other. All facts are from Montana law, verified as of September 2026.
In This Montana Guide:
Contest a Will in Montana: At a Glance
Here are the Montana facts that decide whether you can contest a will in Montana:
| Deadline to contest | A will admitted to probate informally may be contested by commencing a formal testacy proceeding within the LATER of 12 months from the informal probate OR 3 years from the decedent’s date of death (Mont. Code Ann. § 72-3-122). Separately, no probate, testacy, or appointment proceeding of any kind may be started more than 3 years after death, subject to the exceptions in § 72-3-122. Once a FORMAL testacy order has been entered, it is final as to all persons and may be vacated only on the narrow grounds in § 72-3-317 — a petition based on a later-discovered will or a previously unknown heir must generally be filed within 12 months of the formal testacy order. |
| What starts the clock | Two clocks run at the same time and the contestant gets whichever expires later: (1) the date the will was informally probated by the clerk/registrar, and (2) the decedent’s date of death (3 years). Notice to heirs and devisees does not by itself start or shorten the § 72-3-122 contest window, though a person who receives notice of a FORMAL testacy hearing and does not appear is bound by the resulting order (§ 72-3-317). |
| Who can contest | Only an “interested person” may petition. Mont. Code Ann. § 72-1-103 defines “interested person” to include heirs, devisees, children, spouses, creditors, beneficiaries, and any other person having a property right in or claim against the estate, plus persons who have priority for appointment as personal representative and fiduciaries representing interested persons. A beneficiary under a prior will qualifies because that person holds a claim/property right that would be affected. The statute expressly notes that who counts as an interested person can change depending on the particular matter and purpose of the proceeding. |
| No-contest clause | YES with a probable-cause exception. Mont. Code Ann. § 72-2-537 (“Penalty clause for contest”) provides that a provision in a will penalizing an interested person for contesting the will or instituting other proceedings relating to the estate is unenforceable if probable cause exists for instituting the proceedings. So the clause is valid on its face and can forfeit a gift, but it will not be enforced against a contestant who had probable cause. Montana’s parallel trust provision is § 72-38-1014. |
| What the filing is called | A “petition for formal testacy proceeding” (also called a petition for formal probate of a will, or a petition to set aside or vacate an informal probate and for adjudication of intestacy or of a prior will), filed under Mont. Code Ann. § 72-3-301 and § 72-3-302 in the district court handling the estate. It is a probate petition in the existing estate file, not a separate civil complaint. Title 72, chapter 12, part 2 supplies additional will-contest procedure, including § 72-12-206 on fees and expenses. |
| Court | The Montana District Court (state trial court of general jurisdiction) for the county of proper venue. Montana has no separate probate or surrogate court — district courts hold original probate jurisdiction, and the Clerk of District Court acts as registrar for informal proceedings. |
| Jury trial | YES. Mont. Code Ann. § 72-1-208 provides that, if duly demanded, a party is entitled to trial by jury in a formal testacy proceeding and in any proceeding in which a controverted question of fact arises as to which a party has a constitutional right to jury trial. If there is no right to a jury or the right is waived, the court may in its discretion call a jury, but that verdict is advisory only. |
| Typical cost | UNVERIFIED. Montana does not publish official cost figures for contested will litigation. Note that under Mont. Code Ann. § 72-12-206, when the validity or probate of a will is contested by court action, the attorney fees and costs incurred in defending the will must be paid by the contesting party if the will is confirmed in probate — a real financial exposure worth discussing with a licensed Montana attorney before filing. |
The Deadline to Contest a Will in Montana
The window is short in some states and long in others, and it is measured from a specific event rather than from the day you learned about the will. That is why the first thing to find out is the date the will was admitted and whether you received formal notice. If the deadline has not run, everything else on this page is available to you.
If it has, the remaining options are narrow and usually involve proving you never got the notice the law required.
Grounds to Contest a Will in Montana
The grounds are set out in Mont. Code Ann. § 72-3-310 (burdens in contested cases) and § 72-3-321: lack of testamentary intent, lack of testamentary capacity, undue influence, fraud, duress, mistake, and revocation. Improper execution / failure to meet the signing and witnessing requirements of § 72-2-522 is also a basis, because the proponent must make prima facie proof of due execution.
Forgery is a ground and, under § 72-2-524 and § 72-3-321, evidence of fraud or forgery defeats the self-proving shortcut and forces live proof of execution.
Who has to prove what: Mont. Code Ann. § 72-3-310 splits the burden. Proponents of the will carry the burden of establishing prima facie proof of due execution in all cases (and, if they petitioned, prima facie proof of death and venue). Contestants then carry the burden of establishing lack of testamentary intent or capacity, undue influence, fraud, duress, mistake, or revocation.
Each party has the ultimate burden of persuasion on the matters for which it has the initial burden. The civil standard — preponderance of the evidence — applies.
Montana case law recognizes that a confidential or fiduciary relationship combined with suspicious circumstances can raise a presumption or inference of undue influence that shifts the burden of going forward to the will’s proponent; the ultimate burden of persuasion still rests with the contestant under § 72-3-310. Undue influence itself is defined at § 28-2-407.
Who Can Contest a Will in Montana
Only an “interested person” may petition. Mont. Code Ann. § 72-1-103 defines “interested person” to include heirs, devisees, children, spouses, creditors, beneficiaries, and any other person having a property right in or claim against the estate, plus persons who have priority for appointment as personal representative and fiduciaries representing interested persons. A beneficiary under a prior will qualifies because that person holds a claim/property right that would be affected.
The statute expressly notes that who counts as an interested person can change depending on the particular matter and purpose of the proceeding. Being unhappy with the will is not standing; losing something because of it is. Check the earlier will and the intestate rules for Montana before filing, because they decide whether you are an interested person.
No-Contest Clauses in Montana
YES with a probable-cause exception. Mont. Code Ann. § 72-2-537 (“Penalty clause for contest”) provides that a provision in a will penalizing an interested person for contesting the will or instituting other proceedings relating to the estate is unenforceable if probable cause exists for instituting the proceedings.
So the clause is valid on its face and can forfeit a gift, but it will not be enforced against a contestant who had probable cause. Montana’s parallel trust provision is § 72-38-1014.
The Steps to Contest a Will in Montana
Step one is the deadline check above. Step two is evidence: the medical records around the signing date, the names of the witnesses, the drafting lawyer’s file, and the financial records that show who benefited.
Step three is the filing — A “petition for formal testacy proceeding” (also called a petition for formal probate of a will, or a petition to set aside or vacate an informal probate and for adjudication of intestacy or of a prior will), filed under Mont. Code Ann. § 72-3-301 and § 72-3-302 in the district court handling the estate.
It is a probate petition in the existing estate file, not a separate civil complaint. Title 72, chapter 12, part 2 supplies additional will-contest procedure, including § 72-12-206 on fees and expenses.. Step four is discovery and, in most cases, a settlement conference; the small minority that reach trial are decided by a jury if requested.
Settling Instead of Fighting
ALLOWED. Mont.
Code Ann. § 72-3-131 and § 72-3-132 authorize a compromise of any controversy over admission of an instrument to formal probate, the construction/validity/effect of a governing instrument, or the administration of the estate; after notice to all interested persons the district court may approve the agreement on finding that the contest or controversy is in good faith and that the effect on interests represented by fiduciaries is just and reasonable,
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and the approved compromise binds all parties.
Mont. Code Ann. § 72-3-915 separately allows competent successors to alter their own shares by written agreement signed by all affected, which the personal representative must follow subject to creditors, taxes, and costs of administration. Mediation is commonly used and district courts may order alternative dispute resolution.
Other Montana rules: (1) Montana is a full Uniform Probate Code state (Title 72, chapters 1-3), so a will can be admitted informally by the Clerk of District Court with no hearing — many families never see a judge, and the 12-month contest clock in § 72-3-122 starts quietly at that registrar filing. (2) No ante-mortem / pre-death will validation proceeding exists in Montana.
(3) Self-proved wills under § 72-2-524 satisfy execution requirements without any attesting witness testimony, unless there is evidence of fraud or forgery (§ 72-3-321); a signature on the self-proving affidavit counts as a signature on the will itself if needed to prove due execution.
(4) Montana recognizes holographic wills — a will in the testator’s own handwriting and signed by the testator is valid with no witnesses (§ 72-2-522), and these are contested more often on capacity and authenticity. (5) Montana also recognizes documents that fail formalities under the harmless-error / clear-and-convincing standard in § 72-2-523. (6) Fee-shifting under § 72-12-206 puts defense fees on an unsuccessful contestant when the will is confirmed.
(7) A formal testacy order is broadly final under § 72-3-317, so acting during the informal window matters. Many estates can resolve these disputes by agreement under § 72-3-131; you may be able to file on your own using the district court forms, but deadlines and fee-shifting are unforgiving — check with your state’s court or a licensed Montana attorney about your specific situation.
This is general reference information, not legal advice, and no outcome can be guaranteed.
The Evidence That Wins or Loses a Will Contest
Capacity cases turn on the weeks around the signing: the medical chart, prescriptions, a dementia diagnosis, and what the drafting lawyer and the witnesses saw that day. A will signed in a lawyer’s office with two disinterested witnesses and a self-proving affidavit is hard to attack; a will signed at a kitchen table with the main beneficiary present is not.
Undue influence cases turn on the relationship — who drove the parent to the appointment, who chose the lawyer, who was in the room, and whether the new will departed sharply from earlier ones and from what the parent said to other people.
Improper execution is the narrowest ground and the cleanest: Montana sets exact witness and signature rules, and a will that misses them fails regardless of what the signer intended. Before you contest a will in Montana, gather the prior wills, the medical releases, and the names of everyone at the signing.
Most of that evidence has to be requested formally once the case is filed, and the deadline does not wait for it.
What to Expect When You Contest a Will in Montana
A will contest is a lawsuit about the document, not about fairness. When you contest a will in Montana, the court asks whether the person who signed it had capacity, signed it freely, and signed it correctly. It does not ask whether the split was reasonable. That is why the strongest cases rest on medical records and witness accounts from the weeks around the signing.
Most families who contest a will in Montana settle. Courts encourage it, many states have family settlement rules that let the heirs agree to a different division, and a settlement avoids the cost and delay of trial. The deadline, the grounds, and the no-contest clause above are the three facts that set your bargaining position before any of that begins.
You don’t have to do this alone
If you are settling a loved one’s estate in Montana, your state’s probate court self-help center and free legal-aid offices can walk you through the process at no cost. For an active probate or a deadline, talk to a licensed probate attorney in your state.
Key Takeaways: Contest a Will in Montana
- The deadline is everything: the window to contest a will in Montana closes on a fixed schedule, and the court cannot reopen it for a late but valid claim.
- Grounds are specific: you contest a will in Montana on capacity, undue influence, fraud, duress, or bad execution, never on unfairness alone.
- Standing first: only an interested person can contest a will in Montana; check whether you inherit under the prior will or the intestate rules.
- Read the no-contest clause: whether the state enforces it decides how much risk it takes to contest a will in Montana.
- Evidence is medical and financial: records, witnesses to the signing, and the drafting lawyer’s file decide most cases when you contest a will in Montana.
- Settlement is common: most families who contest a will in Montana settle before trial, often through the state’s family settlement rules.
- Find the admission date: the day the will was admitted is the day the clock to contest a will in Montana usually starts.
- Prior wills matter twice: they give you standing to contest a will in Montana and show how far the last will departed from the pattern.
You May Also Like
Official Montana Sources & Resources
- Montana Probate Court: https://courts.mt.gov/forms/
- Montana Will Contest Statute: https://mca.legmt.gov/bills/mca/title_0720/chapter_0030/part_0010/section_0220/0720-0030-0010-0220.html
- Internal Revenue Service — Estate Tax: irs.gov
- Cornell Legal Information Institute: law.cornell.edu/wex
This Montana guide was last verified against official sources in September 2026. Laws change — verify with your state court or a licensed attorney.
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Disclaimer: This guide is informational only and is not legal or tax advice. Estate, probate, and tax laws change and vary by state and county. Verify current rules and dollar figures with your state’s court, statute, or a licensed attorney or tax professional before acting. For urgent matters like an active probate or a tax deadline, consult a licensed professional in your state right away.