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Illinois WARN Act: who is covered and how much notice

Illinois has its own layoff notice law on top of the federal WARN Act. This is what it says, read from the state’s own pages as of 2026-10-27, with the sources.

The rule

Employers with 75 or more full-time employees (or 75 or more employees working at least 4,000 hours a week) must give 60 days’ written notice to affected employees, their representatives, the Department of Commerce and Economic Opportunity and the local chief elected official. A mass layoff is 25 or more full-time employees who are at least one third of the site, or 250 or more.

How it differs from the federal rule

Lower employer size (75) and lower mass-layoff counts than the federal 500.

This is general information, not legal advice. The federal WARN Act applies in every state as well; see the WARN Act in plain language.

Sources

Illinois WARN Act questions

Does Illinois have its own WARN Act?
Yes. Employers with 75 or more full-time employees (or 75 or more employees working at least 4,000 hours a week) must give 60 days’ written notice to affected employees, their representatives, the Department of Commerce and Economic Opportunity and the local chief elected official. A mass layoff is 25 or more full-time employees who are at least one third of the site, or 250 or more.
How is Illinois's rule different from the federal WARN Act?
Lower employer size (75) and lower mass-layoff counts than the federal 500.
How many days of notice does Illinois require?
60 days is the longest notice period the state's law sets for the employer's notice. The federal Act requires 60 days, and the federal rule applies in every state.

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