WARN Act notice requirements for a mass layoff or reduction in force

Every row below comes from the statute at 29 U.S.C. 2101 to 2109 or the Department of Labor regulations at 20 CFR Part 639. The citation is on the row so you can open the source rather than take our word for it.

The clearest statement of it is in 20 CFR 639.6(b), which says that while part-time employees are not counted in determining whether plant closing or mass layoff thresholds are reached, such workers are due notice. And part-time is a defined term that catches more people than the phrase suggests: it covers anyone averaging fewer than 20 hours a week or employed fewer than 6 of the 12 months preceding the notice date, including workers who work full-time. A full-time hire who started five months ago is a part-time employee for WARN purposes.

Sources: 20 CFR 639.3(a), 639.3(e), 639.3(h), 639.3(i)(7), 639.6(b).

Almost every WARN summary mentions the 30-day window. Far fewer mention the second one, and it is the rule that turns a series of small, carefully sized layoffs into a violation. Section 639.5(a)(1) tells an employer to do two separate calculations.

There is one way out of the 90-day window, and it is a burden the employer carries. Notice is not required if the employer demonstrates that the separate employment losses are the result of separate and distinct actions and causes, and are not an attempt to evade the requirements of WARN. Read that carefully. Separate timing is not enough. Separate decisions are not enough either if they trace back to the same cause. Three rounds of cuts in one quarter, all driven by the same revenue shortfall, are one cause wearing three dates.

Two smaller timing rules sit alongside it. When employees are not all terminated on the same date, the date of the first individual termination within the statutory 30-day or 90-day period is what triggers the 60-day requirement, and the first and each subsequent group is entitled to a full 60 days of notice. And the headcount used to test coverage is measured on the date the first notice is required. If that snapshot is clearly unrepresentative, near the peak or trough of an employment cycle, a more representative number such as a recent average may be used instead, though the regulation warns that alternative methods cannot be used to evade WARN.

Sources: 20 CFR 639.5(a)(1)(i), 639.5(a)(1)(ii), 639.5(a)(2); 29 U.S.C. 2102(d).

WARN thresholds are measured at a single site of employment, which is why a distributed company can lay off 80 people nationwide and owe nothing, while a company with everyone in one office owes notice at 50. The regulations were written in 1989 and never contemplated a fully remote workforce, but they do answer the question, and the answer is not the one people expect.

The examples the regulation gives are railroad workers, bus drivers and salespeople, but the words do the work regardless of the era. A remote employee is not a site of one. They attach to the office their work comes from or the office they report into, and that means a remote-first company with a nominal headquarters can concentrate a lot of people at an address almost nobody visits. Run the count that way before concluding a distributed layoff is under the threshold.

Sources: 20 CFR 639.3(i)(3), (i)(4), (i)(6), (i)(8); N.J.S.A. 34:21-1.

The threshold counts are counts of employment losses, and the definition has three limbs. The third is the one that catches companies trying to avoid a layoff altogether.

There is also a transfer carve-out worth planning around. An employee has not suffered an employment loss if, before the closing or layoff, the employer offers a transfer to a different site within reasonable commuting distance with no more than a 6-month break, or offers a transfer to any site regardless of distance with no more than a 6-month break and the employee accepts within 30 days. Reasonable commuting distance is judged on geographic accessibility, the quality of the roads, customarily available transportation and usual travel time. One caution: an offer of reassignment should not be treated as a transfer if the new job amounts to a constructive discharge, and where the transfer is beyond commuting distance the employer can still become liable if the offer is not accepted. The regulation's own advice is to give the 60-day notice as part of the transfer offer.

Sources: 20 CFR 639.3(f)(1), 639.3(f)(3), 639.4(b), 639.5(b).

There is no single WARN notice. There are three, with different content, and a generic letter sent to all three audiences will be short on at least one of them. All notice must be specific, and the information must be based on the best information available to the employer when it is served.

Two practical points. First, the word date in these requirements means either a specific date or a 14-day period during which separations are expected, and where a 14-day period is used the notice must go out at least 60 days before the first day of that period. Second, notice can be made conditional on an event, such as the renewal of a major contract, but only where the event is definite and its outcome will necessarily lead to a covered action within 60 days. Errors caused by events that later change, or minor inadvertent errors, are not intended to be the basis for finding a violation.

Sources: 20 CFR 639.7(a) to (f).

This is the most commonly misstated part of WARN. An exception does not mean you can skip notice. Section 639.9 requires the employer to give as much notice as is practicable, which in some circumstances may be notice after the fact, and to include a brief statement of the reason for reducing the notice period on top of every element otherwise required. The employer bears the burden of proving the exception applies.

Note which exception is missing from the mass layoff column. The faltering company exception applies to plant closings but not to mass layoffs, so a company burning cash while it hunts for a funding round cannot use it to shorten notice on a reduction in force. That is the single most common misreading of section 639.9, and it lands on exactly the companies most likely to need it.

Sources: 20 CFR 639.9(a), 639.9(b), 639.9(c); 29 U.S.C. 2102(b).

Start with what the remedy is not. Under 29 U.S.C. 2104(b) the listed remedies are exclusive and a federal court has no authority to enjoin a plant closing or mass layoff. Nobody can force you to reverse the decision. The exposure is money, calculated per employee, per day.

Two things in that table are worth acting on rather than just reading. The rate is the higher of the average regular rate over the employee's last 3 years and the final regular rate, so anyone whose pay was cut recently is valued at their old number, and the arithmetic is per person rather than an average. And the $500 a day civil penalty is avoidable outright: it does not apply if the employer pays each aggrieved employee what is owed within 3 weeks from the date the shutdown or layoff was ordered. If a notice failure is discovered late, that three-week clock is the most valuable deadline in the statute.

Sources: 29 U.S.C. 2104(a)(1) to (a)(6), 2104(b).

A federal analysis is only the first half. Several states set lower coverage thresholds, longer notice periods, or extra obligations, and they apply on top of WARN rather than instead of it. These are the four that most often change the answer for a US company under 200 employees. Others exist, including Hawaii, Iowa, Maine, Maryland, Minnesota, New Hampshire, Tennessee, Vermont and Wisconsin, so confirm the states you actually employ people in.

Two structural differences are worth holding on to. California has no percentage test at all, so 50 separations at a covered establishment triggers notice regardless of how large the site is, while federal WARN would need those 50 to be a third of the workforce. And New York reaches down to 25 employees, which is half the federal floor. A 300-person company running a 30-person cut in Manhattan is clear of federal WARN and squarely inside the state law.

Almost every number in this analysis is a pay rate multiplied by a number of days, which makes a reduction in force a compensation modeling problem as much as a legal one. Three places where having current pay data for the affected roles changes the decision:

On that last point, the roles that absorb the work are usually the ones already sitting low in their range, and the fastest way to see it is a compa ratio calculation across the team that remains. If the cut changes what a job is, the job needs re-pricing against published federal wage data rather than against the old internal number, and the wider salary structure has to be checked for the grades that just lost their midpoint logic. When backfilling starts again, the postings themselves are governed by state pay transparency laws, and the classification of any restructured role is a separate question answered by the exempt vs non exempt test.

Sources: Worker Adjustment and Retraining Notification Act, 29 U.S.C. 2101 to 2109; US Department of Labor regulations, 20 CFR Part 639; California Labor Code 1400 to 1408 as amended by SB 617 (Stats. 2025 Ch. 229); New York Labor Law article 25-A and New York State Department of Labor guidance; the Millville Dallas Airmotive Plant Job Loss Notification Act, N.J.S.A. 34:21-1 et seq., as amended by P.L.2022 c.142; Illinois Worker Adjustment and Retraining Notification Act, 820 ILCS 65. This page is general information about published law, not legal advice. A reduction in force turns on your own facts and on states not covered here, so confirm the plan with employment counsel before you act.