Illinois Mini-WARN Act: 60 Days' Notice at 75 Employees, Explained

Federal WARN sets its employer threshold at 100 full-time workers. Illinois sets it lower: under the Illinois Worker Adjustment and Retraining Notification Act, 820 ILCS 65, an employer with 75 or more full-time employees must give 60 days' written notice before a covered plant closing or mass layoff. A company with 80 full-time workers can be exempt from federal WARN and still owe Illinois notice, with the back-pay liability and penalties a missed notice brings.

Illinois is heavy in the national data: Layoff Atlas counts it third among states in the 90-day notice window, at 4,626 reported workers, behind Washington (17,050) and California (13,427). Nationally the window holds 673 notices covering 63,421 workers, updated October 28, 2026 — reported plans, not confirmed job losses.

Who the Illinois law covers

The Act applies to a business enterprise employing 75 or more full-time employees, or 75 or more employees working at least 4,000 hours per week in aggregate, not counting overtime. Part-time employees are excluded from the headcount. The federal test instead looks for 100 or more on either measure.

So mid-size employers fall inside the Illinois law while sitting outside the federal one, and an employer near the line cannot rely on headcount alone: the 4,000-hour test can pull in a workforce with many part-time hours. The law does not apply to federal, state, or local governments, and practitioner summaries note charitable and tax-exempt institutions are also excluded.

What triggers notice

Illinois requires 60 days' advance written notice of a plant closing or a mass layoff, and practitioner summaries of the statute also list relocation among the triggering events — a trigger federal WARN does not separately cover.

A plant closing is the permanent or temporary shutdown of a single site, or of facilities or operating units within it, causing an employment loss of 50 or more full-time employees during any 30-day period.

A mass layoff is a reduction in force, not caused by a plant closing, causing losses at a single site during any 30-day period of either 25 or more full-time employees making up at least one-third of the site's full-time workforce, or 250 or more regardless of proportion. In some cases losses are measured across 90 days instead, so splitting one reduction into smaller waves does not automatically escape the law.

Take a warehouse with 90 full-time workers that lays off 30: it has cut one-third of its site workforce, so Illinois notice is triggered, even though the same employer would owe no federal notice. Laying off 20 out of 90 triggers neither law, falling below both the 25-worker and the one-third tests.

Who must receive the notice

Notice goes to the affected employees and their representatives, to the Department of Commerce and Economic Opportunity, and to the chief elected official of each municipal and county government where the site sits. A site near a boundary can sit in one city and one county, and both officials need the notice.

The notice should also carry practical detail: the expected date of the first separation and the schedule for later ones, the job titles affected, and the names of the employees holding those jobs. A vague announcement that a site "may close" is not a substitute.

What happens when notice is short or missing

An employer that fails to give the required notice is liable to each affected employee for back pay and benefits for the violation period, up to 60 days, and may face a civil penalty of up to $500 per day for failing to notify government units. The remedies mirror federal WARN, so one layoff can violate both laws.

Illinois WARN is a notice law, not a severance law: it does not by itself require severance pay. Severance generally comes from employer policy, a contract, a collective bargaining agreement, or a separation agreement. New Jersey and Maine are the exceptions among mini-WARN laws, with their own severance mandates; Illinois is not one.

How Illinois shows up in the layoff data

Layoff Atlas' Illinois archive holds 4,880 non-cancelled imported notices reporting 763,430 workers, with 31 counts unavailable and no future effective dates at the time of writing. Those totals span many years and cover imported records only — not to be confused with the 90-day window figure of 4,626 above.

Year by year, the picture is steadier than headlines suggest: 115 notices covering 16,955 workers so far in 2026, against 136 notices and 17,563 workers in 2025 and 131 notices and 14,931 workers in 2024. The 2020 spike — 454 notices, 74,180 workers — remains the outlier. Because Illinois covers employers down to 75 workers, more Illinois layoffs generate a formal notice than the same layoff would in a state with no mini-WARN law.

What to check if you get an Illinois WARN notice

Check the employer size: at 75 or more full-time employees, Illinois notice is in play even when federal WARN is not. Check the dates: notice should arrive at least 60 days before the first separation and name that date and the schedule. Check the recipients: you, your union if any, the state commerce department, and your local chief elected officials should all have received it. Check the titles and names listed — errors can matter if the layoff is challenged. And remember: a notice is a reported plan, not a confirmed job loss, and a filing can be amended or cancelled — so keep the letter itself, not just the announcement.

Data source: Layoff Atlas