Under the Miller Act, 40 U.S.C. § 3133(b)(2), certain claimants on federal construction contracts must serve written notice on the prime contractor within 90 days of the date they last furnished labor or materials to the project. This requirement applies specifically to claimants who do not have a direct contractual relationship with the prime contractor — most commonly second-tier subcontractors and material suppliers to subcontractors. Claimants with a direct contract with the prime contractor are not required to give this notice. Missing the 90-day deadline is a complete bar to a payment bond claim under the Miller Act. There is no grace period, no substantial compliance exception, and no court can revive a claim that was not timely noticed.
Who Must Send the Miller Act 90-Day Notice?
Not every subcontractor on a federal project must send the Miller Act notice — the requirement turns entirely on your contractual relationship with the prime contractor.
Under 40 U.S.C. § 3133(b)(2), the notice requirement applies to claimants who do not have a direct contract with the prime contractor. In plain terms: if you are a sub-to-a-sub, a supplier to a subcontractor, or otherwise two or more tiers removed from the prime, you must send the 90-day notice or you lose your bond claim rights entirely.
First-tier subcontractors — those with a direct contract with the prime — are not required to send the notice. They may bring a payment bond claim without it.
Practical examples:
- Electrical sub contracted directly with the prime → No notice required.
- Drywall supplier selling to an electrical sub → Notice required.
- HVAC sub contracted directly with the prime → No notice required.
- Insulation sub contracted with the HVAC sub → Notice required.
If you are unsure of your tier position, review your subcontract carefully. Who signed it, and who are they contracted to? That answer tells you whether the 90-day notice is mandatory for your bond claim.
What Triggers the 90-Day Clock on a Federal Bond Claim?
The 90-day period begins running from the date you last furnished labor or materials on the project, under 40 U.S.C. § 3133(b)(2).
"Last furnished" means the final day you actually performed compensable work or delivered materials that were incorporated into — or genuinely intended for incorporation into — the project. Courts have consistently scrutinized what qualifies as a legitimate last-furnishing date. Corrective work, punchlist items, and demobilization activities may or may not extend the period depending on the circuit.
What does NOT extend the clock:
- Sending invoices or demand letters
- Returning unused materials
- Post-substantial-completion visits for warranty or inspection
- Internal administrative activities
What typically does extend the clock:
- Furnishing additional materials that are genuinely incorporated into the work
- Performing additional labor at the direction of the contractor on the same project scope
Because the triggering date is fact-specific and controlling circuit authority on borderline activities varies, document every day you furnish labor or materials on federal projects. Keep delivery receipts, daily logs, and signed tickets. If your last confirmed furnishing date is in dispute, you cannot safely calculate your deadline without a clear record.
What Are the Content Requirements for the Miller Act Notice?
The Miller Act sets out specific content that the notice must contain. Under 40 U.S.C. § 3133(b)(2), the written notice must include:
- A statement of the amount claimed, or
- The nature of the labor or materials furnished, or both.
The statute requires the notice to be served on the prime contractor — not the contracting officer, not the bonding company, and not the property owner (there is no private property owner on a federal project, but the distinction matters when contractors confuse federal and state bond claim procedures).
There is no single federally mandated form. The statute specifies content requirements, not a prescribed form. However, the notice must be in writing. Verbal notice does not satisfy the statute.
Minimum content a Miller Act notice should include:
- Your name and contact information
- The name of the federal project and project location
- The name of the prime contractor
- The name of the subcontractor you contracted with (if you are a second-tier claimant)
- A description of the labor or materials you furnished
- The amount claimed or a statement of the nature of what you furnished
- The date of last furnishing
Including more detail is not harmful. A notice that overstates the claim amount slightly has generally been treated more leniently than one that omits required content, but courts do scrutinize deficient notices carefully. Do not rely on a bare-bones notice if you can prepare a more complete one.
How Do You Serve the Miller Act Notice on the Prime Contractor?
The Miller Act requires that the notice be served on the prime contractor, but the statute itself — 40 U.S.C. § 3133(b)(2) — does not specify a single method of service. It states the notice must be served "in any manner in which the United States marshal of the district in which the public improvement is situated is authorized by law to serve summons."
In practice, the statute cross-references service of process rules, which means personal delivery or registered or certified mail directed to the prime contractor at its residence or last known place of business are the established methods.
What you should use:
- USPS Certified Mail with a Certificate of Mailing and Return Receipt (electronic or physical green card) — this creates a documented paper trail showing what you sent, when you sent it, and when it was delivered or attempted.
- Personal delivery with a signed acknowledgment from the recipient.
Service timing note: The statute does not expressly state whether service is complete upon mailing or upon receipt. This is a genuinely contested area where circuits have differed. Because the consequence of a defective or untimely notice is loss of your bond claim entirely, the safest practice is to mail your notice well before the 90-day deadline — do not wait until day 88 or 89. USPS First-Class Mail delivers in 1–5 business days domestically, with Certified Mail tracking confirming each step of the delivery chain (USPS Service Standards, 2026). Give yourself at minimum a week of buffer before the deadline.
Who receives the notice: The prime contractor — meaning the contractor who holds the contract directly with the federal government. The notice is not served on the surety, the contracting officer, or a higher-tier sub.
What Are the Miller Act Notice Requirements for Material Suppliers?
Material suppliers who supply to a subcontractor — not directly to the prime — are subject to the same 90-day notice requirement under 40 U.S.C. § 3133(b)(2) that applies to second-tier subs. The analysis is the same: no direct contract with the prime means notice is required.
However, there is an important threshold question for suppliers: does the Miller Act cover your claim at all? Under 40 U.S.C. § 3133(b)(1), the payment bond covers persons who furnish labor or materials "in carrying out the work" under the prime contract. Remote suppliers — those who supply to a supplier rather than to a subcontractor — are not covered under the Miller Act. The Supreme Court addressed the limits of Miller Act coverage in F.D. Rich Co. v. United States ex rel. Industrial Lumber Co., 417 U.S. 116 (1974), and courts continue to apply that framework to determine whether a claimant is sufficiently in the chain of work to have bond claim rights at all.
If you are a first-tier supplier (you supply directly to the prime): No notice required; you may bring a claim directly.
If you are a second-tier supplier (you supply to a subcontractor): Notice required within 90 days of last furnishing.
If you are a third-tier or more remote supplier (you supply to a supplier): The Miller Act likely does not cover your claim at all — notice would not cure the coverage problem.
For material suppliers, the "last furnished" date is typically the date of your final delivery of materials to the project. Keep delivery receipts tied to specific project and contract numbers.
What Happens If You Miss the Miller Act 90-Day Notice Deadline?
Missing the deadline is a complete bar to your Miller Act payment bond claim. There is no provision in 40 U.S.C. § 3133 for late notice, equitable tolling in ordinary circumstances, or substantial compliance that excuses a late filing.
Courts have occasionally examined whether a prime contractor's conduct might estop them from asserting a timeliness defense — for example, where the prime affirmatively misled a claimant about the deadline. That is a narrow and fact-specific doctrine, not a general safety net. You cannot plan around it.
What options remain if you miss the deadline:
- Pursue the prime contractor directly under your subcontract or applicable state contract law — the bond claim is gone, but your contract claim survives if you are within the applicable limitations period.
- Pursue the subcontractor you contracted with directly for breach of contract or on an unjust enrichment theory, depending on your facts.
- Evaluate prompt payment act claims — the federal Prompt Payment Act (31 U.S.C. §§ 3901–3907) creates separate rights for prime contractors and subcontractors on federal projects, including interest on late payments. However, these rights run between prime and sub, and sub and sub-sub — not directly against a surety.
- Document and preserve all other claims — nothing about missing the bond notice deadline affects your right to pursue ordinary contract or quantum meruit claims in the appropriate forum.
The hard lesson: there is no meaningful fallback once the 90-day deadline passes and a bond claim is your primary recovery tool. According to Rabbet's 2024 Construction Payments Report, 82% of contractors face payment waits of over 30 days, up from 49% just two years earlier. On federal projects with a surety bond in place, the Miller Act notice is the mechanism that keeps that bond accessible. Losing it means converting a secured bond claim into an unsecured contract dispute.
Does the Miller Act Apply to All Federal Construction Contracts?
The Miller Act applies to contracts for the construction, alteration, or repair of any public building or public work of the federal government exceeding $150,000, under 40 U.S.C. § 3131(b). Below that threshold, the Miller Act's bonding requirements do not apply.
For contracts between $35,000 and $150,000, federal contracting officers have discretionary authority under the Miller Act's companion provisions, but the mandatory payment bond requirement does not kick in until $150,000.
What this means practically:
- If the prime contract is under $150,000, there may be no Miller Act payment bond at all. Confirm the existence of a bond before structuring your payment recovery strategy around it.
- If the prime contract exceeds $150,000, the prime was required to obtain a payment bond. You can request a copy of the bond and the surety's identity from the contracting officer — 40 U.S.C. § 3133(b)(1) explicitly gives claimants the right to inspect and copy the bond and the contract.
Request that bond documentation early in any federal project. Knowing the surety and bond number before a payment dispute arises puts you in a far stronger position.
How Does the Miller Act Notice Differ from State Preliminary Notices?
The Miller Act notice and state preliminary lien notices serve similar protective purposes but operate under completely different rules.
Key differences:
| Miller Act Notice | State Preliminary Notice | |
|---|---|---|
| Applies to | Federal public construction projects | Private (and some public) state projects |
| Governing law | 40 U.S.C. § 3133 | State statutes (varies by state) |
| Who must serve | Second-tier and below claimants only | Varies — often all subs and suppliers |
| Deadline trigger | Last day of furnishing labor/materials | Typically first day of furnishing (prospective) |
| Notice period | 90 days after last furnishing | Often 20 days from first furnishing |
| Served on | Prime contractor | Owner, GC, lender (varies by state) |
| Protects | Bond claim against surety | Mechanics lien rights against property |
Because federal projects involve government-owned property, mechanics liens cannot attach — there is no private property to lien. The payment bond is the payment protection mechanism, which makes the Miller Act notice the functional equivalent of a preliminary notice on a private job.
State preliminary notice deadlines vary significantly. For deadline calculations across multiple states, use the lien deadline calculator to confirm the specific rules in your state.
For a broader reference on lien and notice deadlines across states, see lien deadline directory.
Frequently Asked Questions
Does a first-tier subcontractor need to send a Miller Act 90-day notice?
No. Under 40 U.S.C. § 3133(b)(2), the notice requirement applies only to claimants who do not have a direct contractual relationship with the prime contractor. If you contracted directly with the prime, you may bring a payment bond claim without sending the 90-day notice.
When does the 90-day period start running?
The 90-day clock begins on the date you last furnished labor or materials to the project. This is the final day of actual performance or delivery — not the date of your last invoice, demand letter, or administrative activity. Courts scrutinize borderline "last furnishing" dates closely, so document every day of work or delivery.
Can I send the Miller Act notice before the project is finished?
Yes. Nothing in 40 U.S.C. § 3133 prohibits early notice. Sending notice before the 90-day deadline — even while the project is still ongoing — is permissible and does not affect your claim. Earlier is always safer.
What happens if the prime contractor ignores or refuses delivery of the notice?
If you sent the notice by certified mail to the prime contractor's last known place of business and it was refused or went unclaimed, courts have generally held that proper mailing satisfies the service requirement. Keep your Certificate of Mailing, tracking records, and any return-to-sender envelopes as evidence of your attempt.
Is there a specific government form required for the Miller Act notice?
No. The Miller Act does not require a specific form. The notice must be in writing and must state the amount claimed or describe the nature of the labor or materials furnished, per 40 U.S.C. § 3133(b)(2). A well-drafted letter on your company letterhead that includes all required information satisfies the statute.
Can I file a Miller Act bond claim if the prime contract was under $150,000?
Probably not under the Miller Act. The statute's mandatory payment bond requirement applies to federal construction contracts exceeding $150,000 under 40 U.S.C. § 3131(b). If the prime contract is below that threshold, there may be no Miller Act bond at all. Verify the existence of a bond by requesting it from the contracting officer before assuming bond claim rights exist.
Does serving the Miller Act notice guarantee I'll get paid?
No. Timely service of the notice preserves your right to bring a payment bond claim — it does not itself create an obligation to pay. You must still establish that you furnished the labor or materials, that payment is owed, and that you fall within the statute's coverage. The notice is a threshold requirement; it opens the door to the claim but does not win it.
How does the Miller Act notice deadline compare to state lien notice deadlines?
The Miller Act runs 90 days from last furnishing and runs backward from the end of your work. Most state preliminary lien notice requirements run forward from first furnishing — often within 20 days. The mechanics are different: state notices are typically sent near the start of a project to preserve lien rights throughout; the Miller Act notice comes near the end as a condition to filing a bond claim. The two systems do not substitute for each other.
Protect Your Bond Claim Rights Before the Deadline Passes
The Miller Act 90-day notice deadline is hard, and it runs from a date — your last day of furnishing — that can sneak up on you when you are focused on finishing a job. Miss it and your bond claim is gone, regardless of how much you are owed or how clearly the prime failed to pay.
Track your federal project deadlines the same way you track your private-work preliminary notice deadlines. According to Rabbet's 2024 Construction Payments Report, slow payments cost the U.S. construction industry an estimated $280 billion in 2024, adding roughly 14% to total construction spending. On a federal project, the payment bond is your primary collection tool — treat the notice deadline that protects it accordingly.
Start tracking your notice and bond claim deadlines on LienFlash. File in about 2 minutes, served by USPS Certified Mail with a Certificate of Mailing PDF you keep as proof — so that if a deadline dispute ever comes up, you have documentation that holds up.