WARN Act thresholds and state notice requirements
Before setting reduction dates, check whether your organization meets the federal WARN employer-size threshold. Federal WARN generally covers employers with at least 100 employees under either of its two counting tests. Whether notice is required also depends on how many employees are affected, where they work, and when the employment losses occur. A plant closing involving at least 50 employment losses at one site within 30 days can require notice. For mass layoffs, the threshold is 50 to 499 losses affecting at least 33% of the workforce, or 500 losses regardless of percentage (20 CFR Part 639). State laws can have different requirements. Federal notice violations can result in up to 60 days of back pay and benefits for each affected employee.
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At a glance
Federal WARN event thresholds. Notice can apply to a plant closing involving 50 employment losses, a mass layoff affecting 50 to 499 employees and at least 33% of the workforce, or a mass layoff affecting 500 or more employees. Employment losses are counted by worksite and timing.
- Federal WARN penalties
- Up to 60 days of back pay and benefits per affected employee, plus a civil penalty of up to $500 per day for failing to notify local government.
- Mass-layoff notice thresholds
- 50 to 499 employment losses at one site within 30 days, affecting at least 33% of the workforce, or 500 or more losses regardless of percentage. A plant closing has a separate 50-loss threshold with no percentage test.
The thresholds and what counts as a loss
First, confirm federal WARN employer coverage. Then count employment losses by worksite and date. The companion note on the WARN Act and 60-day notice covers deadlines, recipients, and required notice content.
- Which employers are covered 100 or more employees
- Federal WARN uses two employer-size tests. An employer is generally covered if it has at least 100 employees excluding part-time workers, or at least 100 employees including part-time workers who collectively work at least 4,000 hours per week, excluding overtime. For this calculation, part-time employees generally work fewer than 20 hours per week or have worked fewer than six of the previous 12 months.
- Plant closing 50 employment losses in 30 days
- A permanent or temporary shutdown of a worksite or an operating unit within it that results in at least 50 employment losses within 30 days. Part-time workers are excluded from the count. There is no percentage requirement.
- Mass layoff Mass-layoff notice thresholds
- A workforce reduction at one site that is not a plant closing. Notice can apply when, in any 30-day period, 50 to 499 employees experience employment losses representing at least 33% of the site's workforce, or when 500 or more employees experience losses regardless of percentage. Part-time workers are excluded from these counts.
Federal WARN generally counts an employment termination, excluding discharges for cause, voluntary departures, and retirements. It also counts layoffs lasting longer than six months and reductions of more than 50% in working hours during each month of a six-month period. For temporary layoffs, track the original start date, any extensions, and the total duration against the six-month limit. An extended temporary layoff may count from its original start date, depending on the reason for the extension and the notice provided.
WARN Act Compliance Toolkit | $79
Track employment losses across rolling 30-day and 90-day periods. Includes a notice timeline, recipient checklist, notice letters with a California addendum, and a dated reference for California, New York, Illinois, and New Jersey.
How the 30-day and 90-day counts work
Federal WARN uses rolling 30-day periods to determine whether a plant closing or mass layoff reaches the notice threshold. Employment losses in separate rounds at the same site can also count together when they occur within 90 days. Several smaller layoffs can trigger notice when their combined employment losses reach the threshold, even if each individual round falls below it. Separate rounds may be treated individually when the employer can show they resulted from separate and distinct actions and causes. Review proposed separation dates, temporary layoff extensions, and reductions in hours across both counting periods before finalizing the reduction schedule.
Checking both periods early gives leadership time to adjust reduction dates and prepare any required notices.
How state WARN rules differ
State WARN laws can cover smaller employers, set longer notice periods, and define covered reductions differently. When federal and state laws both apply, plan for both sets of requirements. Check employer size, event thresholds, notice periods, recipients, and penalties in each affected state. The requirements below cover California, New York, Illinois, and New Jersey. Other states, including Washington, Maine, and Maryland, have additional requirements.
- California
- Applies to establishments with 75 or more employees. A mass layoff involving 50 or more employees can require notice regardless of the percentage affected. The law also covers qualifying terminations and relocations of 100 miles or more.
- New York
- Covers employers with 50 or more full-time employees. A mass layoff can require notice when 25 full-time employees experience employment losses representing at least one-third of the site's workforce. The notice period is 90 days.
- Illinois
- Covers employers with at least 75 full-time employees, or at least 75 employees who collectively work 4,000 hours per week. The mass-layoff threshold is 25 full-time employment losses representing at least one-third of the workforce, or 250 losses regardless of percentage.
- New Jersey
- Covers employers with 100 or more employees counted across their locations. The law aggregates qualifying New Jersey sites, requires 90 days of notice, and mandates severance of one week of pay per year of service for covered events.
The Fair Warning Act was introduced in Congress in January 2026 and proposed changes to federal WARN. The proposal was pending at the time of this review.
Remote employee worksite assignments also matter when reviewing each affected state's requirements.
How remote employees affect the single-site count
Worksite assignments matter because federal WARN counts employment losses by worksite. Federal regulations dating to 1989 address worksite assignments. Applying those rules to permanent home-based work raises additional questions. For employees who work outside a regular site, the regulations look to the location serving as their home base, the location assigning their work, or the location receiving their reports (20 CFR 639.3(i)(6)). For employees working permanently from home, the assigned worksite can affect which employment losses count toward WARN thresholds. Courts have reached different conclusions about how federal single-site rules apply to permanent remote work. The Zulily class actions filed in the Southern District of Ohio in May 2024 and the Western District of Washington in September 2024 examine how WARN worksite rules apply to a largely remote workforce.
New York specifically addresses remote workers in its WARN regulations. Remote employees based at a New York site count toward that site's thresholds. Document each remote employee's assigned worksite and reporting relationship, and include that information in your WARN analysis.
Have employment counsel review your worksite assignments, employment-loss counts, and notice plan before setting reduction dates.
Check the numbers before setting dates
The free Does Your Layoff Trigger WARN? quick check helps you review your worksite, planned dates, and state requirements. It identifies federal and state thresholds for further review, directly in your browser.
Use the WARN Act Compliance Toolkit to calculate employment losses across rolling 30-day and 90-day periods, build a notice timeline, and prepare notice letters with the recipient checklist. It includes a California addendum and a dated reference for California, New York, Illinois, and New Jersey. The RIF Complete System brings selection planning, financial modeling, and WARN notice preparation together. It includes the WARN Act Compliance Toolkit. For selection decisions and separation agreements, see the related notes on defensible RIF selection and OWBPA release rules for employees age 40 and older.
Research and sources
Primary sources and review dates
- U.S. Department of Labor, Plant Closings and Layoffs (WARN). Which employers are covered, covered events, and the 60-day notice requirement. Federal WARN is codified at 29 U.S.C. 2101 and following. dol.gov, Plant Closings and Layoffs
- Electronic Code of Federal Regulations, 20 CFR Part 639. Employment-loss definitions, single-site rules, 90-day aggregation, and notice requirements, including recipient-specific requirements in section 639.7. ecfr.gov, 20 CFR Part 639
- California Department of Industrial Relations, Cal-WARN Act. California Labor Code sections 1400 to 1408. Establishments with 75 or more employees, qualifying layoffs of 50 or more employees in 30 days, relocations of at least 100 miles, and the 60-day notice requirement with no percentage test. dir.ca.gov, the Cal-WARN Act
- California Employment Development Department, WSIN25-14 on SB 617. Notice-content requirements for notices issued on or after 1 January 2026, including workforce development board coordination, CalFresh information, employer contact details, and coordination of services within 30 days. The triggers are unchanged. edd.ca.gov, WSIN25-14
- New York State Department of Labor, WARN. Coverage of private employers with 50 or more full-time employees, mass-layoff thresholds of 25 full-time employees at 33% or 250 regardless of share, remote employee treatment, 90-day notice, and required recipients. dol.ny.gov, the NYS WARN Act
- Illinois Department of Labor, Illinois WARN (820 ILCS 65). Employer coverage, plant closings of 50 or more, mass layoffs, 60-day notice, and back pay and penalty provisions. Definitions appear in 56 Ill. Adm. Code 230.110. labor.illinois.gov, WARN
- New Jersey Department of Labor and Workforce Development, File a WARN Notice. The Millville Dallas Airmotive Plant Job Loss Notification Act and its 2023 amendments, including coverage of employers with 100 or more employees nationwide, statewide establishment counting, the 50-termination threshold, 90-day notice, mandatory severance of one week per year of service, and state or court approval for severance waivers. nj.gov, File a WARN Notice
Common questions
What counts as an employment loss under WARN?
Federal WARN generally counts involuntary terminations other than discharge for cause, layoffs lasting longer than six months, and reductions of more than 50% in working hours during each month of a six-month period. Voluntary departures and retirement are excluded. An extended temporary layoff may count from its original start date, depending on the circumstances and notice provided.
What is the 90-day aggregation rule?
Employment losses in separate rounds at the same site can count together when they occur within 90 days, even when each round falls below the WARN threshold. Separate rounds may qualify for an exception when the employer can show they resulted from separate and distinct actions and causes. Review all planned rounds together when determining whether notice is required.
Which states have additional WARN requirements?
California, New York, Illinois, and New Jersey have requirements that differ from federal WARN. California covers establishments with 75 or more employees and qualifying mass layoffs of 50 or more employees, along with certain terminations and relocations of at least 100 miles. New York covers employers with at least 50 full-time employees, requires 90 days of notice, and can trigger mass-layoff notice at 25 full-time employment losses when the percentage requirement is met. Illinois covers employers meeting its 75-employee threshold and has a mass-layoff threshold of 25 full-time losses affecting one-third of the workforce, or 250 regardless of percentage. New Jersey covers employers with at least 100 employees, aggregates qualifying New Jersey sites, requires 90 days of notice, and mandates one week of severance per year of service for covered events. Washington, Maine, Maryland, and other states also have additional requirements. Review the rules in every affected state.
Do remote employees count toward a single site?
Federal WARN worksite rules can be difficult to apply to employees working permanently from home. Courts have reached different conclusions, and the Zulily class actions filed in 2024 address this question. New York expressly counts remote employees based at a New York site. Include affected remote employees in your worksite analysis and confirm the appropriate counting and notice treatment with employment counsel.
Tools for the next step
Check your worksite, planned dates, and state requirements in about 3 minutes. See which WARN thresholds may apply to your planned reduction.
FreeCalculate rolling 30-day and 90-day employment losses, plan notice dates, and prepare recipient lists and letters. Includes a California addendum and references for California, New York, Illinois, and New Jersey.
$79The RIF Complete System brings selection planning, financial modeling, and WARN notice preparation together. It includes the WARN Act Compliance Toolkit.
$199Organize selection scoring, four-fifths adverse-impact review, older-worker disclosures, and separation tracking.
$129Model severance, fully loaded labor costs, net savings, and payback before finalizing headcount decisions.
$89
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