Does Illinois have its own WARN Act?

Yes. Illinois has its own WARN law (Illinois WARN Act (820 ILCS 65/1 et seq.)) with different thresholds than federal. It applies to employers with 75+ employees and requires 60 days notice.

How many days notice does Illinois require for a mass layoff?

Illinois requires 60 days advance notice for covered mass layoffs.

Resources WARN ActIllinois

Illinois WARN Act

Illinois WARN Act (820 ILCS 65/1 et seq.)

60-day noticeNo mandatory severance

Key thresholds

Employer minimum

75employees

↓ Lower than federal (100)

Notice required

60days

Same as federal

Employee threshold

25+

AND 33% of workforce

OR 250+ regardless of %

Look-back window

90days

Rolling aggregation period

Key nuances for Illinois

Triggers when 25+ employees AND 33% of workforce at a single site, OR 250+ regardless of percentage. Lower thresholds than federal; catches mid-size layoffs federal WARN misses.

How Illinois differs from federal WARN

Factor	Federal WARN	IL
Employer minimum	100+ employees	75+ employees
Notice required	60 days	60 days
Employee threshold	50+ AND 33%, or 500+	25+ AND 33% or 250+
Covers part-time	No (20+ hrs/wk only)	No
Mandatory severance	No	No
Safe harbors	Faltering company, Unforeseeable business circumstances, Natural disaster	Faltering company, Unforeseeable business circumstances, Natural disaster

Other states

California Connecticut Hawaii Iowa Maine Maryland Massachusetts Minnesota New Hampshire New Jersey New York Tennessee Wisconsin

This page is provided for informational purposes only and does not constitute legal advice. Laws change — always verify with qualified employment counsel before a reduction in force.

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