The WARN Act is the reason large US layoffs rarely come as a complete surprise. Short for the Worker Adjustment and Retraining Notification Act, this 1988 federal law requires certain employers to give workers advance notice before major layoffs and plant closures. Here is what it does, who it covers, and where its limits are.
What the WARN Act requires
At its core, the law is simple: covered employers must provide 60 calendar days' written notice before a plant closing or mass layoff. The notice goes to affected workers (or their union representatives), the state dislocated worker unit, and the local chief elected official.
The purpose is practical, not punitive. Sixty days gives workers time to look for new jobs, seek retraining, and adjust — and gives state workforce agencies time to mobilize rapid-response services like job fairs and unemployment assistance.
Which employers are covered
The federal WARN Act applies to employers with 100 or more full-time employees (part-time workers and those employed fewer than 6 months generally do not count toward the threshold). Private businesses, nonprofits, and quasi-public entities can all be covered. Federal, state, and local government employers are generally not covered.
What counts as a triggering event
Not every layoff triggers WARN. The law defines two triggering events:
Plant closing. The permanent or temporary shutdown of a single site of employment that results in job losses for 50 or more full-time employees during any 30-day period.
Mass layoff. A reduction in force that is not a plant closing but results in job losses at a single site during any 30-day period for:
- 500 or more full-time employees, or
- 50 to 499 full-time employees, if they make up at least 33% of the employer's active full-time workforce at that site.
There is also an aggregation rule: job losses in two or more groups within 90 days can be combined to meet the thresholds, which prevents employers from splitting one large layoff into smaller pieces to dodge the notice requirement.
What the notice must contain
A valid WARN notice is not just a heads-up — it must include specific information: the name and address of the employment site, the expected date of the layoff or closure, whether it is permanent or temporary, the job titles and number of affected workers, and a contact person for more information. This is why WARN filings are such a rich public data source: they are standardized, dated, and filed with state agencies.
Exceptions to the 60-day rule
The law recognizes that 60 days is not always possible. Three narrow exceptions allow shorter notice:
- Faltering company. When a company is actively seeking capital or business that would let it avoid the layoff, and giving notice would hurt those chances. This applies only to plant closings, not mass layoffs.
- Unforeseeable business circumstances. A sudden, dramatic, and unexpected event outside the employer's control — a major client abruptly canceling, for example.
- Natural disaster. Floods, earthquakes, and similar events.
Even when an exception applies, the employer must still give as much notice as practicable and explain why the full 60 days was not possible. Courts interpret these exceptions narrowly.
Penalties for violations
Employers that violate WARN owe each affected worker back pay and benefits for each day of the violation period (up to 60 days), plus potential civil penalties of up to $500 per day payable to the local government. Workers can and do sue — WARN class actions are a well-established area of employment litigation.
State mini-WARN laws go further
Many states were not satisfied with the federal floor and passed their own versions with broader coverage. Notable examples:
- California: covers employers with 75+ employees (vs. 100 federal), with 60 days' notice.
- New York: covers employers with 50+ employees, and requires 90 days' notice — longer than federal.
- Illinois: covers employers with 75+ employees, 60 days' notice.
- New Jersey: among the strictest — 90 days' notice and mandatory severance pay for covered layoffs.
Because thresholds and notice periods differ, WARN data is richer in some states than others. A state with a 50-employee threshold captures layoffs that would never appear under federal rules alone. This is one reason state-by-state comparisons need context: differing rules, not just differing economies, shape the numbers.
What WARN data can and cannot tell you
WARN filings are the best public window into large-scale US layoffs — standardized, dated, and continuously published. But remember their limits: they are reported plans, not confirmed job losses. Notices can be amended or withdrawn. Layoffs below the thresholds never appear. And coverage varies by state depending on local mini-WARN rules.
Used with those caveats in mind, WARN data is unmatched: it shows which employers are cutting, where, when, and at what scale — weeks or months before the effects show up in employment statistics.
Data source: Layoff Atlas tracks US WARN notices by company, state, and effective date.