Preliminary notices in Montana
Subcontractors and suppliers on a private job in Montana serve a notice of right to claim a lien within 20 days after your first day furnishing labor or materials. It is required. That is tighter than the 26-day middle of the states that set a fixed window, so it belongs on day one of the job.
A late notice covers only work in the 20 days before it's sent.
Lien filing deadline in Montana
If the GC hired you, you have 90 days after your last day furnishing labor or materials to record a mechanics lien in Montana, about the same as the national median of 90 days (counted from last furnishing on a sample job). 23 of the 51 jurisdictions we track use this same lien deadline, which makes it the most common rule.
The clock starts on your last day furnishing labor or materials under your contract. In many states, warranty visits and punch list work done mainly to extend the deadline don't restart it, so use your last day of real contract work.
Deadline to sue on the lien
To keep the lien alive you must sue to enforce it within 24 months after recording the lien. If you record on the last possible day, that is about 821 days after your last day on the job, about 456 days longer than the national median of 365 days. 40 of the 48 jurisdictions we track have a shorter overall time to sue and 6 have a longer one.
Because the clock counts from recording, recording early also moves the lawsuit deadline earlier.
How Montana compares
Days are counted on a sample job with the lien recorded on its last allowed day, so states that count from recording or from completion can be compared with those that count from your last day on site. The median is across the jurisdictions with a dated rule on file.
- Preliminary notice (from first day)
- Montana: 20 daysNational median: 25.5 days
- Record the lien (from last day)
- Montana: 90 daysNational median: 90 days
- Sue to enforce (from last day)
- Montana: 821 daysNational median: 365 days
Public and federal projects
Public property can't be liened, so subcontractors and suppliers on state and local public jobs in Montana claim against the GC's payment bond instead. We haven't reduced Montana's bond claim deadlines to one set of numbers, because they vary by agency and project. The governing law is Mont. Code §18-2-201 to -208. Verify the notice and suit deadlines with the statute and the bond itself before the job starts.
Federal jobs in Montana follow the Miller Act instead of state law: those hired by a sub or supplier give the prime contractor notice within 90 days of their last furnishing, and suit is due within 1 year, in federal court. Prime contractors on federal work have no lien or bond claim.
Retainage and prompt payment in Montana
We haven't reduced Montana's retainage and prompt payment rules to single numbers yet: they depend on the agency, the contract size or the contract date. Rather than guess, the table shows "Verify" and the statutes to read are Mont. Code §28-2-2101 to -2105 (prompt pay). Your contract's payment terms still matter, and the federal rules below apply on federal work.
| Public work | Private work | Federal work | |
|---|---|---|---|
| Retainage cap | Verify | Verify | 10% |
| Release | Verify with state statute | Verify with state statute | Released with final payment, or earlier once progress is satisfactory. |
| GC pays subs within | Verify | Verify | 7 days |
| Late-payment interest | Verify | Verify | Treasury prompt payment rate (reset every January and July) |
Not legal advice. Retainage and prompt payment rules differ by agency, contract size and contract date, and change often. Confirm the rules with the current statute, your contract and a construction attorney before relying on them.
Worked example: a HVAC sub in Montana
A HVAC subcontractor hired by the GC on a private elementary school addition in Montana starts work on March 2, 2026 and last furnishes on July 17, 2026. The project is completed on August 28, 2026. Run through Montana's rules, those dates give:
| Deadline | Date | Counted from |
|---|---|---|
| Notice of right to claim a lien | March 22, 2026 Weekend | First furnishing |
| Record the lien | October 15, 2026 | Last furnishing |
| Sue to enforce the lien | October 15, 2028 Weekend | Lien recording |
The first deadline on the calendar is “Notice of right to claim a lien” on March 22, 2026, counted from the day the crew started, long before any payment is late.
2 dates land on a weekend (March 22, 2026, October 15, 2028). Not every state rolls a deadline to Monday, so the safe move is to record or serve by the Friday before.
Open the lien deadline calculator for Montana and enter your own dates to get this table for your job, with countdowns and a PDF deadline calendar.
Check your own dates with the free tools
- Mechanics lien and notice deadline calculator (MT): every notice, lien and suit date for your role, tier and job type.
- Retainage and prompt payment rules (MT): check your contract's retainage against the cap and work out late-payment interest.
- Schedule of values and pay application builder: bill each period with retainage calculated, so what you're owed is documented.
- Cash flow and retainage forecaster: see what slow payment and held retainage do to your bank balance.
Statutes cited
- Mont. Code §71-3-521 to -562
- Mont. Code §18-2-201 to -208 (public bonds)
- Mont. Code §28-2-2101 to -2105 (prompt pay)
- Federal work in Montana: 40 U.S.C. §3131 to §3134 (Miller Act)
Not legal advice. Lien and bond claim rules change and have exceptions for project type, contract terms and how notices are served. Confirm every deadline with the current statute or a construction attorney in the project's state before relying on it. Rules shown as "Verify with state statute" have exceptions or variations we could not reduce to one number.