Montana Mechanic Lien Law: Complete Guide
Your Complete Guide to Mechanic Lien Rights Under Montana Rev. Code §71-3-521 et seq. — Private Works, Payment Bonds & Public Projects
Montana mechanic lien deadline table with toggles for project type and claimant type.
Montana Preliminary Notice & Mechanic Lien Deadlines
Select your project type and role to see the deadlines that apply to you.
Prime Contractor — In privity with the property owner
File the Construction Lien with the county clerk and recorder within 90 days after the claimant's last furnishing of labor or materials. Mail a copy to the owner and the general contractor.
Commence an action to foreclose the Construction Lien within 2 years after the lien is filed.
Preliminary Notice
Mechanic Lien
File the Construction Lien with the county clerk and recorder within 90 days after the claimant's last furnishing of labor or materials. Mail a copy to the owner and the general contractor.
Enforcement
Commence an action to foreclose the Construction Lien within 2 years after the lien is filed.
Montana private project deadlines
Prime Contractor
Preliminary Notice: Not required. A prime contractor in direct contract with the owner is exempt from the Notice of Right to Claim a Construction Lien requirement.
Mechanic Lien: File the Construction Lien with the county clerk and recorder within 90 days after the claimant's last furnishing of labor or materials. Mail a copy to the owner and the general contractor.
Enforcement: Commence an action to foreclose the Construction Lien within 2 years after the lien is filed.
Subcontractors & Suppliers
Preliminary Notice: Serve a Notice of Right to Claim a Construction Lien on the owner within 20 days of first furnishing labor or materials to preserve lien rights for the entire amount owed. If the notice is served later than 20 days after first furnishing, the lien is limited to labor and materials furnished within the 20 days preceding service and any furnishings thereafter. Best practice is to serve the notice at the very start of the project, not at the 20-day cutoff.
Mechanic Lien: File the Construction Lien with the county clerk and recorder within 90 days after the claimant's last furnishing of labor or materials. Mail a copy to the owner and the general contractor.
Enforcement: Commence an action to foreclose the Construction Lien within 2 years after the lien is filed.
Remote Claimants
Preliminary Notice: Serve a Notice of Right to Claim a Construction Lien on the owner within 20 days of first furnishing labor or materials to preserve lien rights for the entire amount owed. If the notice is served later than 20 days after first furnishing, the lien is limited to labor and materials furnished within the 20 days preceding service and any furnishings thereafter. Best practice is to serve the notice at the very start of the project, not at the 20-day cutoff.
Mechanic Lien: File the Construction Lien with the county clerk and recorder within 90 days after the claimant's last furnishing of labor or materials. Mail a copy to the owner and the general contractor.
Enforcement: Commence an action to foreclose the Construction Lien within 2 years after the lien is filed.
Montana public works deadlines
Prime Contractor
Preliminary Notice: Not applicable. The prime contractor is the principal on the payment bond and pursues payment through contract remedies, not a bond claim.
Bond Claim: Not applicable. Construction liens cannot attach to public property in Montana. Prime contractors pursue payment through contract remedies.
Lawsuit to Enforce Bond Claim: Contract remedies against the public owner, subject to any applicable notice-of-claim and limitations periods.
Subcontractors & Suppliers
Preliminary Notice: Serve written notice on the prime contractor by certified mail within 30 days of first furnishing labor or materials, stating that delivery has commenced and identifying the subcontractor.
Bond Claim: File the bond claim within 90 days after completion and acceptance of the contract by the public body. Suit may not be commenced until at least 30 days after the notice is given.
Lawsuit to Enforce Bond Claim: Commence suit on the payment bond within 1 year from the date of the last labor or materials furnished, after expiration of the 90-day waiting period following notice to the prime contractor.
Remote Claimants
Preliminary Notice: Serve written notice on the prime contractor by certified mail within 30 days of first furnishing labor or materials, stating that delivery has commenced and identifying the subcontractor.
Bond Claim: File the bond claim within 90 days after completion and acceptance of the contract by the public body. Suit may not be commenced until at least 30 days after the notice is given.
Lawsuit to Enforce Bond Claim: Commence suit on the payment bond within 1 year from the date of the last labor or materials furnished, after expiration of the 90-day waiting period following notice to the prime contractor.
Montana Mechanic Lien Law Overview
Last updated April 2026 · Reviewed by Thomas Emalfarb, Esq.
Montana construction mechanic lien rights are governed by Montana Revised Code §71-3-521 et seq. This statutory framework provides Construction Mechanic Lien rights to contractors, subcontractors, and material suppliers who furnish labor, equipment, materials, or supplies for the improvement of real property in the State of Montana.
Montana requires a Notice of Right to Claim a Mechanic Lien as a critical prerequisite for most claimants. This notice must be filed with the County Clerk and served on the property owner within 30 days of first performance for non-commercial residential dwellings (4 or fewer families). Persons who furnish directly to the owner, and wage earners or laborers who perform personal labor services, are exempt from this notice requirement.
All claimants must record a Construction Mechanic Lien and serve it on the contracting owner within 90 days after last performance or the contracting owner's Notice of Completion under §71-3-535. The Notice of Right to Claim a Mechanic Lien is effective for one year from filing; if the contract extends beyond one year, a Continuation Notice must be filed to maintain mechanic lien rights.
Montana public works projects require payment bonds — 100% for state projects and 25% for local projects — under Montana Rev. Code §18-2-201 et seq.
Topics on This Page
Montana Mechanic Lien Law: Key Topics
Navigate the critical compliance areas for Montana construction mechanic lien law.
Notice Requirements
Notice of Right to Claim a Mechanic Lien, 30-day filing deadline, Continuation Notice, regulated lender 45-day rule, and exemptions for direct contractors and laborers
Mechanic Lien Deadlines
90-day Construction Mechanic Lien filing deadline, Notice of Completion procedures, and service requirements
Mechanic Lien Enforcement Deadlines
2-year suit deadline, public works payment bond claims, 90-day Notice of Claim on Bond, and surety requirements
Frequently Asked Questions
What statute governs mechanic liens in Montana?
Construction mechanic liens on private projects in Montana are governed by Montana Revised Code §71-3-521 et seq. Public works payment bonds are governed by §18-2-201 et seq., requiring 100% bonds for state projects and 25% for local projects.
Is a preliminary notice required to file a mechanic lien in Montana?
Yes, for most claimants. A Notice of Right to Claim a Mechanic Lien must be filed with the County Clerk and served on the owner within 30 days of first performance (45 days for regulated lender projects) on residential dwellings of 4 or fewer families. Direct contractors and wage earners are exempt.
What is the deadline to file a mechanic lien in Montana?
All claimants must record a Construction Mechanic Lien and serve it on the contracting owner within 90 days after last performance or the owner's Notice of Completion under §71-3-535, whichever comes first. §71-3-536.
How does Montana mechanic lien law differ from other states?
Montana has several unique features: the Notice of Right to Claim a Mechanic Lien must be filed within 30 days (or 45 for lender-funded projects), late notice limits the mechanic lien to the 20-day period before notice was given, the notice expires after 1 year requiring a Continuation Notice, and the enforcement period is a generous 2 years.
What are the notice requirements for Montana public works bond claims?
Suppliers and materialmen must give written notice to the prime contractor within 30 days of first delivery. A written Notice of Claim must be filed with the public authority within 90 days after project completion and formal acceptance under §18-2-204.
What is the deadline to file suit to enforce a Montana construction mechanic lien?
Suit must be filed within 2 years after the date the Construction Mechanic Lien was filed. For public works bond claims, there is no specific statutory provision — the suit deadline is governed by the individual bond terms.