Worker Adjustment and Retraining Notification (WARN) Act (29 USC Chapter 23) offers protection to workers, their families and communities by requiring employers to provide notice 60 days in advance of covered plant closings and covered mass layoffs. This notice must be provided to either affected workers or their representatives (e.g., a labor union); to the State dislocated worker unit; and to the appropriate unit of local government. 
In general, employers are covered by WARN if they have 100 or more employees, not counting employees who have worked less than 6 months in the last 12 months and not counting employees who work an average of less than 20 hours a week. Private, for-profit employers and private, nonprofit employers are covered, as are public and quasi-public entities which operate in a commercial context and are separately organized from the regular government. Regular Federal, State, and local government entities which provide public services are not covered.
Employees entitled to notice under WARN include hourly and salaried workers, as well as managerial and supervisory employees. Business partners are not entitled to notice.
What Triggers Notice
- Plant Closing: A covered employer must give notice if an employment site (or one or more facilities or operating units within an employment site) will be shut down, and the shutdown will result in an employment loss (as defined later) for 50 or more employees during any 30-day period. This does not count employees who have worked less than 6 months in the last 12 months or employees who work an average of less than 20 hours a week for that employer. These latter groups, however, are entitled to notice (discussed later).
- Mass Layoff: A covered employer must give notice if there is to be a mass layoff which does not result from a plant closing, but which will result in an employment loss at the employment site during any 30-day period for 500 or more employees, or for 50-499 employees if they make up at least 33% of the employer’s active workforce. Again, this does not count employees who have worked less than 6 months in the last 12 months or employees who work an average of less than 20 hours a week for that employer. These latter groups, however, are entitled to notice (discussed later).
An employer also must give notice if the number of employment losses which occur during a 30-day period fails to meet the threshold requirements of a plant closing or mass layoff, but the number of employment losses for 2 or more groups of workers, each of which is less than the minimum number needed to trigger notice, reaches the threshold level, during any 90-day period, of either a plant closing or mass layoff. Job losses within any 90-day period will count together toward WARN threshold levels, unless the employer demonstrates that the employment losses during the 90-day period are the result of separate and distinct actions and causes.
AcqLinks and References:
- US Department of Labor Training and Employment Guidance Letter No 3-12 – 30 July 12
-  Website: U.S. Department of Labor: Fact Sheet Worker Adjustment and Retraining Notification Act
- Website: 29 USC Chapter 23 “Worker Adjustment and Retraining Notification (WARN) Act”
- Website: Wikipedia: Worker Adjustment and Retraining Notification (WARN) Act