Montana Prejudgment Interest Rate
United States Montana’s prejudgment interest rate — when a court awards it.
Set by statute Fixed by statute
Montana prejudgment interest is 10% per year, as simple interest under MCA 27-1-211. Prejudgment interest is MANDATORY (not discretionary) under MCA 27-1-211 only when three criteria are met: (1) an underlying monetary obligation exists; (2) the amount of recovery is…
When Montana prejudgment interest applies
Prejudgment interest is MANDATORY (not discretionary) under MCA 27-1-211 only when three criteria are met: (1) an underlying monetary obligation exists; (2) the amount of recovery is certain or capable of being made certain by calculation (liquidated/ascertainable); and (3) the right to recover vests on a particular day. Unliquidated/uncertain claims generally do NOT get mandatory prejudgment interest under 27-1-211.
When it starts accruing
Non-tort/liquidated (MCA 27-1-211): interest runs from the day the right to recover vests (the day the sum became due/certain), except during any time the debtor is prevented by law or by the creditor's act from paying.
Simple or compound
Simple. MCA 31-1-106 legal-rate prejudgment interest is applied as simple interest under Montana practice; MCA 27-1-210 tort interest and MCA 25-9-205 both expressly state interest may not be compounded.
→ Compare with the Montana post-judgment interest rate (interest after judgment)
Prejudgment interest under MCA 27-1-211 — 10% (simple interest). This is PREjudgment interest (accruing before entry of judgment) and is separate from Montana’s post-judgment rate; availability is limited by claim type (see the page). Verify against the statute text. Not legal advice.
Effective-date history
| Effective date | Rate | Basis |
|---|---|---|
| July 9, 2026 | 10% | Statute |
Source & provenance
Latest value retrieved July 10, 2026 (02:55 UTC) from the official source:
https://mca.legmt.gov/bills/mca/title_0270/chapter_0010/part_0020/section_0110/0270-0010-0020-0110.html