What is the WARN Act?
A quick guide to the federal law behind layoff notices.
Overview
The Worker Adjustment and Retraining Notification (WARN) Act is a federal law enacted in 1988. It requires certain employers to give 60 calendar days' advance notice before conducting mass layoffs or plant closings so that workers and communities can prepare.
Who does it apply to?
- Employers with 100 or more full-time employees (or 100+ employees who work a combined 4,000+ hours per week, excluding overtime).
- Covers private, for-profit and non-profit employers. Federal, state, and local government entities are generally exempt.
What triggers a WARN notice?
- Plant closing: a facility or operating unit shuts down, resulting in 50+ employees losing their jobs.
- Mass layoff:a reduction in force that is not the result of a closing but affects 500+ workers, or 50–499 workers if they make up at least 33% of the employer's active workforce.
State-level WARN laws
Many states have their own “mini-WARN” laws with lower thresholds or longer notice periods. For example, California requires notice for layoffs of 50+ employees regardless of workforce percentage. Layoff Detector aggregates filings from states across the country so you can monitor them in one place.
Why does it matter?
WARN notices are an early signal of large-scale job losses. Job seekers, career coaches, recruiters, investors, and local governments all use this data to stay ahead of workforce changes.