Mechanics Liens in New York: The Deadlines That Decide Who Gets Paid

By Eugene Bondar, Esq. · Updated July 1, 2026

If you furnish labor or materials to a construction project and don’t get paid, a mechanics lien is often your most powerful remedy — it attaches your claim directly to the property itself. But lien rights are a use-it-or-lose-it proposition, and the single most common way contractors lose them is simple: waiting too long.

New York’s Lien Law is unusually forgiving on the front end — no preliminary notice is required to preserve your rights, unlike in many states — and unusually strict on the back end. Every step after the work stops runs on a statutory clock.

Every New York mechanics lien deadline, in one place

What you must do	Deadline
File the notice of lien — most private projects	Within 8 months of contract completion or your last furnishing of labor or materials
File the notice of lien — single-family dwelling	Within 4 months of contract completion or last furnishing
File a lien based on unpaid retainage	Within 90 days after the retainage is due
Serve the notice of lien on the owner (and contractor, if you’re a sub or supplier)	No later than 30 days after filing (service up to 5 days before filing also counts)
File proof of service with the county clerk	Within 35 days after filing
Foreclose or extend the lien	Within 1 year of filing
Extend by county clerk filing (most commercial projects, once)	Before the year expires — adds one year
Any further extension, or any single-family extension	Court order only
Respond to an owner’s demand to foreclose	Commence the action (or show cause) within 30 days

The rest of this post explains where each of these comes from and how they trip people up.

The clock starts before you think it does

The filing window under Lien Law § 10 is measured from the completion of your contract or the last date you provided labor or materials — not from when your invoice went unpaid, and not from when negotiations broke down. You may file while the work is still in progress, and sometimes that is exactly the right move. But by the time many contractors accept that a payment dispute is real, a substantial part of the window is already gone.

Two traps inside this rule. First, returning to the site for trivial punch-list or warranty work generally does not restart the clock — courts look for genuine contract work. Second, the short four-month window applies whenever the property is a single-family dwelling, a fact subcontractors working through a GC sometimes never confirm until it’s too late.

Filing is only step one

A lien that is filed must also be perfected. Under § 11, a copy of the notice must be served on the owner — and, if you are a subcontractor or supplier, on the general contractor and the party that hired you — no later than thirty days after filing. Proof of that service must then be filed with the county clerk within thirty-five days, or the lien terminates.

Service is not a formality. Until the owner has been served, the Lien Law protects payments the owner makes in good faith — meaning the fund your lien attaches to can shrink, dollar by dollar, while your notice sits unserved.

Accuracy matters just as much. A willfully exaggerated lien is void under § 39, and § 39-a adds real teeth: liability for the owner’s damages, including attorney’s fees and the amount of the exaggeration. Round numbers, padded change orders, and “negotiating positions” have no place in a notice of lien. An itemized, documented claim gets paid; an inflated one produces motion practice — or a counterclaim.

You have one year — then the lien dies

Under § 17, a mechanics lien lasts one year from filing. Before that year runs, you must either commence a foreclosure action or extend the lien. On most commercial projects, one extension may be filed with the county clerk, adding a year; any further extension requires a court order, and a lien against a single-family dwelling can only be extended by court order. Miss the deadline and the lien lapses automatically.

Owners can compress this timeline. A demand served under § 59 forces the lienor to commence foreclosure — or show cause why the lien should not be discharged — within thirty days. If you hold a lien and receive one, the response window is short and the consequence of ignoring it is losing the lien.

Filing the foreclosure itself is technical: it is a real litigation, necessary parties must be joined, and a corporate lienor cannot appear without counsel. This is the stage where a well-built demand letter and a credible readiness to try the case tend to produce the settlement.

Public projects run on different rules

Liens on public improvements — schools, roads, municipal buildings — don’t attach to the property at all. They attach to the funds due the contractor, are filed with the public entity rather than the county clerk, and run on their own deadlines, including a thirty-day window after the project’s completion and acceptance. If your unpaid work is on a public job, the analysis changes from the first step; see our construction & infrastructure and government procurement practices.

What owners should know

If a lien has been filed against your property, you have tools as well — several of them time-sensitive. You can demand an itemized statement of the claim under § 38 (and move to cancel the lien if the lienor ignores it), bond the lien off to clear title while the dispute plays out, move to discharge a lien that is defective on its face, or serve the § 59 demand and put the lienor to its proof. Which tool fits depends on whether you dispute the debt, the amount, or just need clean title for a closing or refinance.

The practical takeaway

Whether you are owed money or a lien just hit your property, the calendar is the first thing a lawyer should look at — every option above gets narrower with time. We handle lien filings, foreclosures, defenses, and the payment-clause disputes behind them — as Rockland County construction and business counsel and across New York and Northern New Jersey. The initial consultation is free.

Related services: Civil Litigation & Disputes · Construction & Infrastructure

Attorney Advertising. This post is for general informational purposes only and does not constitute legal advice. Deadlines vary by project type and circumstance — consult an attorney about your specific situation.

Frequently asked questions

How long do I have to file a mechanics lien in New York?

On most private projects, the notice of lien must be filed within 8 months of the completion of your contract or the last date you furnished labor or materials. If the property is a single-family dwelling, the window is 4 months. A lien based on unpaid retainage may be filed within 90 days after the retainage becomes due.

When does the filing clock start running?

From your last furnishing of labor or materials to the project — not from the date of your unpaid invoice, and not from when settlement talks break down. Trivial punch-list or warranty work generally does not restart the clock.

How long does a New York mechanics lien last once filed?

One year from filing. Before the year runs, you must either commence a foreclosure action or extend the lien. On most commercial projects one extension can be filed with the county clerk for an additional year; any further extension — and any extension of a lien on a single-family dwelling — requires a court order.

Do I have to serve the lien after filing it?

Yes. A copy of the notice of lien must be served no later than 30 days after filing (service up to 5 days before filing also counts), and proof of service must be filed with the county clerk within 35 days. Until the owner is served, payments the owner makes in good faith can deplete the fund your lien attaches to.

I'm past the deadline. Do I still have a claim?

The lien remedy is gone — New York courts do not extend a missed filing window — but the underlying claims usually survive: breach of contract, quantum meruit, and, on some projects, payment bond or trust fund claims under Article 3-A. The sooner those are assessed, the more options remain.

A lien was just filed against my property. What can I do?

Owners have fast tools: demand an itemized statement of the claim, bond the lien off to clear title, move to discharge a lien that is defective on its face, or serve a demand that forces the lienor to start foreclosure within 30 days or justify the lien. Several of these are time-sensitive, so move promptly.