Montana: Mechanic's Lien Deadlines & Notice Requirements
The short answer
Montana gives a construction lien to anyone who furnishes labor, materials, or even architectural or engineering plans under a 'real estate improvement contract,' with no separate rule for contractors, subcontractors, suppliers, or design professionals. Most subcontractors and suppliers on smaller residential jobs must send a Notice of Right to Claim Lien within 20 days of first furnishing work (45 days if a lender is funding the project, except on an owner-occupied residence); original contractors, laborers, and anyone on a 5-or-more-unit or commercial project are exempt from that notice. Every claimant must then file the lien within 90 days of their own last work or the owner's notice of completion, and — unlike most states — must already have served a copy on the owner before the county clerk will even accept the lien for filing. Once filed, a claimant has 2 years to sue to foreclose it. A separate rule outside the lien chapter voids an unwritten new-home construction contract between a general contractor and owner, and Montana's Supreme Court has held that voiding eliminates the lien for the construction-services portion of the work, though a separate equitable claim for the value of what was actually built can still survive.
| Governing law | Mont. Code Ann. Title 71, ch. 3, part 5, §§ 71-3-521 to 71-3-564, 'Construction Liens' — comprehensively rewritten by 1987 Mont. Laws ch. 202, which repealed the older single-track lien statute and renumbered the surviving sections into the current scheme |
|---|---|
| Who can claim a lien | Broad and tier-neutral: § 71-3-523 lets any person who furnishes services or materials under a 'real estate improvement contract' claim a lien to secure that contract price, with no separate track for a general contractor versus a subcontractor of any tier or a supplier. § 71-3-522(6)(a) defines 'real estate improvement contract' broadly enough to include a subcontract (not just a direct contract with the owner) and expressly covers 'preparation of plans, surveys, or architectural or engineering plans or drawings,' so design professionals qualify too, even for work never actually built. Excluded: contracts for mining, timber, or crop-type work (§ 71-3-522(6)(b)) |
| Preliminary notice | Required for most claimants, but with broad carve-outs: § 71-3-531(1) exempts an original contractor dealing directly with the owner, a wage earner or laborer, anyone working on a dwelling for 5 or more families, and anyone working on a project that is partly or wholly commercial — so the notice mainly matters for subcontractors and suppliers on smaller (1-4 unit) residential jobs. Deadline: within 20 days of first furnishing labor or materials, or 45 days if the owner is paying with funds from a regulated lender secured against the project — except that extension never applies to a contract on an owner-occupied residence, which always stays on the 20-day clock (§ 71-3-531(4)). Missing the deadline doesn't forfeit the lien outright; it narrows the lien to only the work furnished within the 20 (or 45) days before notice was actually given (§ 71-3-531(3)). The notice must also be filed with the county clerk within 5 business days of being given to the owner, lapses after 1 year unless renewed, and an unexpired notice on file is itself a precondition to filing the lien at all (§ 71-3-531(6)) |
| Deadline to file the lien | 90 days after either (a) the claimant's own final furnishing of services or materials, or (b) the owner's filing of a notice of completion (§ 71-3-535(1)) — the same 90 days for every claimant tier, with no separate window for a prime contractor. One exception: a lien based solely on preparing plans, surveys, or architectural or engineering drawings not used to actually change the property attaches only when it is filed, not at the 'commencement of work' that governs every other lien (§ 71-3-535(5)-(6)) |
| Notice of completion effect | An owner may file a notice of completion any time after 'completion,' which the statute defines as either the owner's written acceptance of the work or 30 days of cessation of labor on the project (§ 71-3-533(1)-(2)). Filing it gives claimants an alternate 90-day filing trigger under § 71-3-535(1)(b) alongside their own last-furnished date. The owner must also publish the notice weekly for 3 successive weeks in a local newspaper and send a copy to anyone who already gave a preliminary Notice of Right to Claim Lien (§ 71-3-533(5)-(6)) |
| Serving the lien on the owner | Unlike states where a claimant serves the lien after recording it, Montana makes service a precondition to filing: the county clerk 'may not file the lien' at all unless the claimant certifies, at the time of filing, that a copy has already been served on every owner of record, by personal service or by certified mail with return receipt requested (§ 71-3-534(2); § 71-3-535(2)(b)). There's no separate post-filing grace period for service, since an unserved lien can't be filed in the first place |
| Deadline to sue to foreclose | All actions to enforce a construction lien must be commenced within 2 years from the date the lien was filed (§ 71-3-562) — a flat window, with no statutory notice-of-contest procedure that shortens it and no provision in the chapter letting the parties extend it by agreement |
| Homestead/residential extras | Two distinct rules, one inside the lien chapter and one outside it. Inside: § 71-3-531(4)'s extended 45-day preliminary-notice deadline for lender-funded projects expressly excludes 'a contract on an owner-occupied residence,' so notice on an owner-occupied home is always due within the standard 20 days even when a lender is funding draws. Outside the lien chapter entirely: § 28-2-2201(1)-(2) (Title 28, Contracts) requires a 'residential construction contract' — an agreement between a general contractor and owner to build a new residence — to be in writing and to contain specific insurance, payment, inspection, and warranty disclosures. The Montana Supreme Court held in Mandell v. Bayliss, 2016 MT 205, 384 Mont. 377, that an oral residential construction contract is void under § 28-2-2201(2), and because lien rights arise from a 'real estate improvement contract' under § 71-3-523, voiding the contract eliminates the contractor's lien rights for the construction-services portion of the work — though the statute doesn't bar a separate equitable claim (quantum meruit/unjust enrichment) for the value the owner actually received |
Compare this rule across all 50 states + DC →
The short answer
Montana's construction-lien law reaches anyone who furnishes labor, materials,
or even architectural or engineering plans under a "real estate improvement
contract" — contractors, subcontractors of any tier, suppliers, and design
professionals are all covered by the same broad rule. Most subcontractors and
suppliers on smaller residential jobs must send a Notice of Right to Claim
Lien within 20 days of first furnishing work (45 days if a lender is funding
the project, except on an owner-occupied residence, which always stays on the
20-day clock); an original contractor dealing directly with the owner, a
laborer, or anyone on a 5-or-more-unit or commercial project doesn't need to
send that notice at all. Every claimant must then file the lien within 90
days of their own last work or the owner's notice of completion, and — unlike
most states — must already have served a copy on the owner before the county
clerk will even accept the lien for filing. Once filed, a claimant has 2
years to sue to foreclose it. A separate rule outside the lien chapter voids
an unwritten construction contract between a general contractor and a
homeowner for a new residence, and Montana's Supreme Court has held that this
also wipes out the contractor's lien rights for the construction-services
portion of the work, though a separate equitable claim for the value actually
delivered can still survive.
Requirements one by one
Governing law
Montana's private construction lien lives in Mont. Code Ann. Title 71,
Chapter 3, Part 5, §§ 71-3-521 to 71-3-564, titled "Construction Liens." The
part was comprehensively rewritten by 1987 Mont. Laws ch. 202, which repealed
the older statute's early sections and renumbered the surviving pieces into
the modern 71-3-5xx structure still in force today.
Who can claim
Section 71-3-523 sets one broad rule: any person who furnishes services or
materials "pursuant to a real estate improvement contract" may claim a
construction lien to secure that contract's price — with no separate track
for a general contractor versus a subcontractor of any tier, or a supplier.
Section 71-3-522(6)(a) defines "real estate improvement contract" broadly
enough to include a subcontract, not just a contract directly with the
owner, and it expressly lists "preparation of plans, surveys, or
architectural or engineering plans or drawings" among the covered work — so
architects and engineers qualify too, even if their plans are never actually
built. Contracts for mining, timber removal, or crop work are carved out of
lien coverage entirely (§ 71-3-522(6)(b)).
Preliminary notice
Montana requires a Notice of Right to Claim Lien, but the exceptions are wide
enough to change who it actually applies to. Section 71-3-531(1) exempts an
original contractor who deals directly with the owner, a wage earner or
laborer, anyone furnishing work on a dwelling for five or more families, and
anyone furnishing work on a project that is partly or wholly commercial — so
in practice, the notice mostly matters for subcontractors and suppliers on
smaller (one-to-four-unit) residential jobs. The notice is due within 20 days
of first furnishing labor or materials, or 45 days if the owner is paying
with funds a regulated lender advanced and secured against the project — but
that 45-day extension never applies to "a contract on an owner-occupied
residence," which stays on the 20-day clock regardless of how the project is
financed (§ 71-3-531(4)). Missing the deadline doesn't forfeit the lien
outright: it narrows the lien to only the services or materials furnished
within the 20 (or 45) days before notice was actually given (§ 71-3-531(3)).
The claimant must also file a copy of the notice with the county clerk within
5 business days of giving it to the owner; that filed notice lapses after one
year unless renewed, and having an unexpired notice (or continuation) on file
is itself a precondition to filing the lien at all (§ 71-3-531(6)).
Deadline to file the lien
Section 71-3-535(1) gives every claimant, regardless of tier, 90 days to file
the lien after either their own "final furnishing of services or materials"
or the owner's filing of a notice of completion. There's one carve-out: a
lien based solely on preparing plans, surveys, or architectural or
engineering drawings that aren't used to actually change the property
attaches only when it's filed, not at "commencement of work" like every other
lien under the chapter (§ 71-3-535(5)-(6)).
Notice of completion effect
An owner may file a notice of completion any time after "completion,"
which the statute defines as either the owner's written acceptance of the
work or 30 days of cessation of labor on the project (§ 71-3-533(1)-(2)).
Filing it gives claimants a second 90-day trigger under § 71-3-535(1)(b)
alongside their own last-furnished date. The owner must publish the notice
weekly for three successive weeks in a local newspaper and send a copy to
anyone who already gave a preliminary Notice of Right to Claim Lien
(§ 71-3-533(5)-(6)).
Serving the lien on the owner
Most states let a claimant serve a recorded lien on the owner within some
number of days after filing. Montana runs the sequence in the opposite
order: the county clerk "may not file the lien" at all unless the claimant
certifies, at the time of filing, that a copy has already been served on
every owner of record — by personal service or by certified mail with return
receipt requested (§ 71-3-534(2); § 71-3-535(2)(b)). Because service is a
filing precondition rather than a post-filing step, there's no separate grace
period for late service; an unserved lien simply can't be filed.
Deadline to sue to foreclose
Section 71-3-562 sets a flat window: "All actions under this part must be
commenced within 2 years from the date of the filing of the lien." Nothing in
the chapter lets another party's notice or demand shorten that window, and
nothing lets the parties extend it by agreement.
Homestead/residential extras
Two separate rules touch residential work. Inside the lien chapter,
§ 71-3-531(4)'s 45-day preliminary-notice extension for lender-funded
projects never applies to "a contract on an owner-occupied residence" — that
project always runs on the standard 20-day notice clock even when a bank is
funding construction draws. Outside the lien chapter, § 28-2-2201(1)-(2)
(Title 28, Contracts) requires a "residential construction contract" — an
agreement between a general contractor and an owner to build a new residence
— to be in writing and to include specific insurance, payment, change-order,
inspection, and warranty disclosures. In Mandell v. Bayliss, 2016 MT 205, 384
Mont. 377, the Montana Supreme Court held that an oral residential
construction contract is void under § 28-2-2201(2), and because lien rights
arise from a "real estate improvement contract" under § 71-3-523, voiding the
contract eliminated the contractor's lien rights for the construction
services he provided. The court also held, though, that the statute doesn't
bar a separate equitable claim (there, quantum meruit/unjust enrichment) for
the value the owner actually received from the work.
What trips people up
The service-before-filing sequence catches people who assume Montana works
like most other states: a claimant who records the lien first and plans to
mail the owner a copy "in a few days" risks having the county clerk refuse
the filing outright, since the certification of service has to accompany the
lien, not follow it. Second, the preliminary-notice exemptions turn on the
specific contract relationship and the project's size or character, not on a
claimant's trade — the same subcontractor might owe no notice on a six-unit
apartment building down the street while owing one on the single-family
remodel next door, and the 45-day lender-funded extension quietly disappears
the moment the project is an owner-occupied home. Third, a handshake deal for
building a new house is a real trap for a general contractor: § 28-2-2201
requires that contract to be in writing, and Mandell v. Bayliss confirms that
skipping it doesn't just weaken a breach-of-contract claim — it can eliminate
the lien entirely for the construction work, leaving only a slower, no-lien
equitable claim to recover the value delivered.
Common questions
Do I need to send a preliminary notice on every Montana job?
No. You don't need to if you have a direct contract with the owner, if you're
a wage earner or laborer, or if the project is a dwelling for five or more
families or is partly or wholly commercial. Otherwise — mainly, subcontractors
and suppliers on smaller residential jobs — you do, within 20 days of first
furnishing work (45 days if lender funds are paying for it, unless the home
is owner-occupied).
Can I serve the lien on the owner after I file it?
No. Montana requires the opposite order: the county clerk can't accept your
lien for filing unless you certify, at the time of filing, that you've
already served a copy on every owner of record by personal service or
certified mail with return receipt requested.
What happens if the owner records a notice of completion while I'm still
working?
You still have 90 days to file your lien, but the clock can run from either
your own last furnishing of work or the owner's notice of completion,
whichever applies to your situation under § 71-3-535(1) — so track both
dates.
I built a house for a homeowner on a handshake deal — can I lien it if they
don't pay?
Not for the construction-services portion. Montana law requires that kind of
contract to be in writing, and the state Supreme Court has held that an oral
residential construction contract is void, which eliminates the general
contractor's lien rights for the construction work. You may still be able to
recover the value of what you built through a separate equitable claim, but
that isn't the same as having a lien.
Statutes and sources
- Mont. Code Ann. § 71-3-521 (scope) —
https://mca.legmt.gov/bills/mca/title_0710/chapter_0030/part_0050/section_0210/0710-0030-0050-0210.html
(accessed 2026-07-05) - Mont. Code Ann. § 71-3-522 (definitions) —
https://mca.legmt.gov/bills/mca/title_0710/chapter_0030/part_0050/section_0220/0710-0030-0050-0220.html
(accessed 2026-07-05) - Mont. Code Ann. § 71-3-523 (who may claim a construction lien) —
https://mca.legmt.gov/bills/mca/title_0710/chapter_0030/part_0050/section_0230/0710-0030-0050-0230.html
(accessed 2026-07-05) - Mont. Code Ann. § 71-3-531 (notice of right to claim lien; exceptions) —
https://mca.legmt.gov/bills/mca/title_0710/chapter_0030/part_0050/section_0310/0710-0030-0050-0310.html
(accessed 2026-07-05) - Mont. Code Ann. § 71-3-533 (notice of completion) —
https://mca.legmt.gov/bills/mca/title_0710/chapter_0030/part_0050/section_0330/0710-0030-0050-0330.html
(accessed 2026-07-05) - Mont. Code Ann. § 71-3-534 (filing with county clerk; notification of
owner) —
https://mca.legmt.gov/bills/2007/mca/71/3/71-3-534.htm
(accessed 2026-07-05) - Mont. Code Ann. § 71-3-535 (attachment of lien; filing; 90-day deadline) —
https://mca.legmt.gov/bills/mca/title_0710/chapter_0030/part_0050/section_0350/0710-0030-0050-0350.html
(accessed 2026-07-05) - Mont. Code Ann. § 71-3-562 (limitation on actions; 2-year foreclosure
window) —
https://mca.legmt.gov/bills/2007/mca/71/3/71-3-562.htm
(accessed 2026-07-05) - Mont. Code Ann. § 28-2-2201 (residential construction contracts —
disclosure and warranty requirements) —
https://mca.legmt.gov/bills/2017/mca-update-112018/title_0280/chapter_0020/part_0220/section_0010/0280-0020-0220-0010.html
(accessed 2026-07-05)
Source links
Every statute quoted above, linked, with the date we checked it.