Montana judgment & prejudgment interest rates
Everything Montana charges in interest on a money judgment or an overdue debt, in one place — the rate after judgment and the rate before it, each verified against the statute and linked to its full page with sources, history, and carve-outs.
| Metric | Rate | Basis |
|---|---|---|
| Post-judgment interest | 9.75% | Set by statute |
| Prejudgment interest | 10% | Fixed by statute |
Post-judgment interest
Montana's post-judgment interest rate is 9.75% per year. Montana post-judgment interest is currently 9.75% — a statutory formula rate under Mont. Code Ann. § 25-9-205 that resets periodically. For a judgment involving a contractual obligation that specifies an interest rate, post-judgment interest is paid at the rate specified in the…
→ Full Montana post-judgment page — statute, effective-date history, and source.
Prejudgment interest
Montana's prejudgment interest rate is 10% per year (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…
→ Full Montana prejudgment page — when it applies, accrual, compounding, and carve-outs.
→ Calculate Montana prejudgment interest
Frequently asked
What is the post-judgment interest rate in Montana?
As of January 1, 2026, the Montana post-judgment interest rate is 9.75% per year. Montana judgment interest — a formula rate, reset periodically.
What is the prejudgment interest rate in Montana?
Montana's prejudgment interest rate is 10% per year (fixed by statute). 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…
Is Montana judgment interest simple or compound, and when does it start?
See each rate's page for the exact compounding rule, accrual date, and statutory carve-outs — Montana prejudgment interest in particular turns on the type of claim.
Compare every state on the state interest-rate index and the prejudgment interest index, or run the numbers with our interest calculators. Reference data only — not legal advice.