The thresholds, and what counts as a loss
Three questions decide federal coverage: is the employer big enough, is the event big enough, and does it happen at a single site inside the counting window. The companion note on the WARN Act and the 60-day notice covers what the notice must say and who must receive it; this note is about the counting that decides whether notice is owed at all.
Covered employer 100 or more
100 or more employees, not counting workers averaging fewer than 20 hours a week or employed fewer than 6 of the last 12 months, or 100 or more including part-time workers whose combined hours reach 4,000 a week excluding overtime.
Plant closing 50 losses in 30 days
A shutdown of a single site, or of one or more operating units within it, causing employment losses for 50 or more employees in any 30-day period. No percentage test applies.
Mass layoff 50 at 33%, or 500
A reduction that is not a plant closing, causing losses at a single site in any 30-day period for 50 to 499 employees who make up at least 33% of the active workforce, or for 500 or more regardless of the share.
All three triggers count employment losses, and the definition does the quiet work. An employment loss is a termination other than for cause, quitting, or retirement; a layoff that runs longer than 6 months; or a cut of more than half an employee’s hours in each month of a 6-month stretch. A short layoff expected to last under 6 months is not an employment loss when it happens, so logging one never inflates the count by itself. The trap runs the other way: a short layoff that stretches past 6 months becomes an employment loss counted from the day it began, which can put an employer out of compliance retroactively.
The 30-day windows and the 90-day aggregation rule
The thresholds are tested in rolling 30-day windows, and an employer that splits one reduction into smaller rounds does not escape them. If two or more groups of losses at a single site each fall below the trigger but together cross it within any 90-day period, they count as one covered event unless the employer proves the rounds came from separate and distinct actions and causes. The safe planning posture is to run every contemplated separation date through both windows before any date is set.
The example is fictional, but the shape is the common one: no single round looks reportable, and the windows say otherwise. This is why WARN counting belongs in the planning meeting, not in a post-announcement review.
The mini-WARN table, dated
State mini-WARN laws stack on top of the federal Act rather than replacing it, and the stricter rule wins on every dimension: employer size, trigger count, notice length, recipients, and remedies. Four states are modeled here because they are the ones most reductions touch; they are not the whole map. Washington, Maine, Maryland, and others run their own versions, and the set keeps growing.
These thresholds change as legislatures amend the laws, and Congress proposed a federal WARN overhaul in January 2026, the Fair Warning Act, which is pending legislation only and not law. Verify the current federal rule and the law of every state where affected employees sit, including remote employees, before relying on any table, this one included.
The single-site question the courts have not settled
Federal WARN counts losses at a single site of employment, and the regulations were written before fixed-home remote work existed at scale. Whether a remote worker’s single site is the home, the office the worker reports into, or somewhere else decides whether remote losses count toward a site’s threshold, and the few courts to rule have conflicted. The Zulily class actions, filed in the Southern District of Ohio in May 2024 and the Western District of Washington in September 2024, test exactly this question for a workforce that was largely remote when it was cut.
Two practical anchors hold while the law develops. New York answers the question by statute: remote employees based at a New York site count toward its thresholds. And the cautious practice many employers have adopted is to include remote workers in both the counting and the notice when their assigned site is affected, on the reasoning that over-noticing costs a stamp and under-noticing costs 60 days of back pay per person. That is risk management, not a settled rule, and it belongs in a counsel conversation.
Pause before you run a reduction near these numbers. WARN turns on counts, windows, and site definitions that are easy to get wrong, and the state overlays count differently than the federal floor. If a planned reduction is anywhere near a federal or state threshold, have employment counsel confirm the headcount, the single-site read, the aggregation math, the notice period, and every required recipient before any date is set or any employee is told. An exposure read from any tool, ours included, is a signal to involve counsel, never a clearance.
Count it before you plan it
The free Does Your Layoff Trigger WARN quick check runs the site, window, and state questions above in your browser and returns an exposure profile to review with counsel. The WARN Act Compliance Toolkit carries the full engine: an aggregation calculator that computes the 30-day and 90-day windows for every logged loss, the timeline math, the notice-letter set with the California addendum, and the dated state reference. For the whole reduction, the RIF Complete System sequences it: plan the restructure, model the savings, stay compliant on notice. The selection side of a defensible reduction is covered in defensible RIF selection, and the release rules for workers 40 and over in the OWBPA release rules.
Where these rules come from
Primary sources
- U.S. Department of Labor, Plant Closings and Layoffs (WARN). The agency overview of the federal Act: coverage at 100 or more employees, 60 calendar days of notice, and the covered-event definitions. WARN is codified at 29 U.S.C. 2101 and following. dol.gov, Plant Closings and LayoffsChecked 23 July 2026
- Electronic Code of Federal Regulations, 20 CFR Part 639. The federal WARN regulations: the employment-loss definition, the single-site rules, the 90-day aggregation provision, and the notice content elements in section 639.7 for each recipient class, including the short form for government recipients. ecfr.gov, 20 CFR Part 639Checked 24 July 2026
- California Department of Industrial Relations, Cal-WARN Act. California’s law at Labor Code sections 1400 to 1408: 75-employee establishments, 50 or more losses in 30 days, relocations of 100 or more miles, and 60 days of notice with no percentage test. dir.ca.gov, the Cal-WARN ActChecked 23 July 2026
- California EDD, WSIN25-14 on SB 617. The notice-content expansion effective for notices issued on or after 1 January 2026: workforce development board coordination statement and contacts, CalFresh information, and employer contact details, with services arranged within 30 days where the employer coordinates. The triggers are unchanged. edd.ca.gov, WSIN25-14Checked 23 July 2026
- New York State Department of Labor, WARN. New York’s law: private employers with 50 or more full-time employees, remote workers based at the site counted, triggers at 25 full-time employees at 33% or 250 regardless of share, 90 days of notice, and the expanded recipient list. dol.ny.gov, the NYS WARN ActChecked 23 July 2026
- Illinois Department of Labor, Illinois WARN (820 ILCS 65). The Illinois thresholds: employers with 75 or more full-time employees or 75 or more workers aggregating 4,000 hours a week, a mass layoff of 25 full-time employees at 33% or 250, a closing at 50, 60 days of notice, and the back-pay and penalty provisions, with the definitions in 56 Ill. Adm. Code 230.110. labor.illinois.gov, WARNChecked 24 July 2026
- New Jersey Department of Labor and Workforce Development, File a WARN Notice. The state’s page for the Millville Dallas Airmotive Plant Job Loss Notification Act reflecting the 2023 amendments: 100 or more employees nationwide, statewide establishment counting, a 50-termination trigger, 90 days of notice, and mandatory severance of one week per year of service that cannot be waived without state or court approval. nj.gov, File a WARN NoticeChecked 23 July 2026
The four states above are the modeled set, not the whole map, and thresholds, counting rules, and remedies change as legislatures amend these laws. The remote-worker single-site question is unsettled and litigation-driven. General information, not legal advice. Confirm the current federal rule and the law of every state where affected employees sit before acting on any figure here.
Tools that run this count
Screen it free, then run the full engine
Common questions
A termination other than for cause, quitting, or retirement; a layoff lasting longer than 6 months; or a reduction of more than half an employee’s hours in each month of a 6-month period. A short layoff expected to run under 6 months is not a loss when it happens, but one that stretches past 6 months becomes a loss counted from the day it began. Confirm the counting for your facts with employment counsel.
Two or more groups of employment losses at a single site within any 90-day period add together into one covered event if each group alone falls below the threshold but the combined count crosses it, unless the employer proves the groups came from separate and distinct actions and causes. Staggering a reduction into small rounds does not avoid notice; it usually just delays the discovery that notice was owed.
A growing list. California reaches 75-employee establishments with a 50-loss trigger and no percentage test; New York covers 50-employee employers with triggers at 25 and a 90-day notice; Illinois reaches 75 full-time employees with triggers at 25; New Jersey counts statewide, requires 90 days, and mandates severance of one week per year of service. Washington, Maine, Maryland, and others run their own versions, so check every state where affected employees sit.
Unsettled under federal WARN. The regulations predate fixed-home remote work, the few courts to rule have conflicted, and the Zulily class actions filed in 2024 test the question directly. New York counts remote workers based at a site by statute, and the cautious practice many employers follow is to include remote workers in the counting and the notice when their assigned site is affected. Treat it as a counsel question, not a settled rule.