Illinois Mechanic Lien Law (770 ILCS 60)

Last updated: February 2026

What Is an Illinois Mechanic Lien?

Under the Illinois Mechanics Lien Act (770 ILCS 60), a mechanic lien is a statutory claim against real property that secures payment for labor, materials, or services furnished to improve that property. The lien attaches to the land and any improvements, giving the claimant a security interest that can be enforced through a court-ordered sale of the property if the debt remains unpaid.

The Act is classified as a "remedial" statute intended to protect those who improve real property, yet Illinois courts have consistently held that every procedural step must be followed exactly as written. This combination of broad purpose and narrow procedural tolerance is what makes mechanic lien practice in Illinois both powerful and unforgiving.

Who Can File a Mechanic Lien in Illinois?

Section 1 of the Act identifies the parties entitled to a mechanic lien. Eligible claimants include:

• General contractors with a direct contract with the property owner
• Subcontractors who furnish labor or materials under a subcontract
• Sub-subcontractors and lower-tier contractors in the contractual chain
• Material suppliers who deliver goods incorporated into the improvement
• Architects, engineers, and land surveyors who provide professional services

Choosing the Right Remedy: Role and Project Type

The remedy available to you depends on your role on the project and whether the project is private, public, or federal. An experienced construction attorney can evaluate your situation and recommend the best path forward.

Not sure whether your project is public or private? Our guide to public vs private construction payment remedies explains how to classify your project and which statute applies.

Private Project Mechanic Liens Under 770 ILCS 60

On private construction projects, the mechanic lien is the primary payment remedy. The lien attaches to the property being improved, and the claimant can ultimately force a judicial sale to recover what is owed. Key requirements include:

• A verified claim for lien that includes the contract description, balance due, and correct property description
• Recording the lien with the County Recorder of Deeds within four months of the claimant's last furnishing date
• Serving a copy of the recorded lien on the owner within 30 days of recording
• Subcontractors generally must serve a Section 24 notice on the owner within 90 days of their last furnishing date (exceptions may apply, such as parties on the GC's sworn statement)

For a detailed walkthrough of each step, see our step-by-step filing process guide.

Public Project Alternatives: Lien on Funds and Bond Claims

You cannot place a mechanic lien on government-owned property. Illinois law provides two alternative remedies for public construction projects:

Why Strict Compliance Is Required in Illinois

Although the Mechanics Lien Act is a remedial statute designed to protect those who improve real property, Illinois courts demand exact compliance with every procedural requirement. A single defect — an incorrect property index number, a notice served one day late, or a misspelled owner name — can result in the complete forfeiture of the lien.

This "strict compliance" doctrine means that even valid underlying debts can become unenforceable if the lien paperwork is flawed. For a complete walkthrough of what information must be included and how to avoid common errors, see our lien filing process guide.

Key Deadlines Every Claimant Must Know

Missing a statutory deadline is the most common way construction professionals lose their payment rights in Illinois. The critical windows include:

For a complete breakdown of every deadline organized by claimant role, visit our filing deadlines by role reference page. If you have received a Section 34 demand letter, see our Section 34 demand letters guide for response strategy.

Enforcing and Defending Against Mechanic Liens

Recording a lien is not the final step. To collect, a claimant must file a foreclosure lawsuit in the circuit court of the county where the property is located. The complaint must name the owner, the general contractor, and every party with a recorded interest in the property. If the lien is sustained, the court may order a judicial sale to satisfy the claim.

Property owners and general contractors facing a lien have defenses available, including challenging procedural defects, contesting the amount claimed, or arguing that the owner paid the general contractor before receiving any subcontractor notice. Under 770 ILCS 60/38, an owner may also petition to substitute a bond for the lien, releasing the property while the dispute is litigated.

County-Specific Filing Guidance

Emalfarb Law LLC represents construction professionals across Chicagoland and Northern Illinois. We have extensive experience recording liens and litigating payment disputes in the following jurisdictions:

Related Illinois Construction Payment Resources

Frequently Asked Questions About Illinois Mechanic Liens