Business 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 for 50 or more employees during any 30-day period.
Mass Layoff
A covered employer must give notice if there is a mass layoff, which does not result from a business closing, but 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 percent of the employer’s active workforce.
An employer must also give notice if the number of employment losses, which occur during a 30 day period, fails to meet the threshold requirement of a business closing or mass layoff but the number of employment losses of two 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 a business closing or mass layoff. Job losses within any 90-day period will count 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.