MA WARN Act: What Employers Need to Know About WARN Notices in Massachusetts

If you’re searching for the MA WARN Act, you’re likely planning (or responding to) a mass layoff, plant closing, or major reduction in force—and you need to know whether you must issue a WARN notice, who must receive it, and how to stay compliant. This guide explains how the federal WARN Act (Worker Adjustment and Retraining Notification Act) works in Massachusetts, when a “duty to warn letter” applies, and how state-by-state WARN laws can change your obligations.

What is the WARN Act (Worker Adjustment and Retraining Notification Act)?

The Worker Adjustment and Retraining Notification Act (WARN Act) is a federal law requiring certain employers to provide advance written notice (a “WARN notice”) before:

a plant closing, or
a mass layoff

The goal is to give affected employees and communities time to prepare for job loss. WARN is administered by the U.S. Department of Labor and is primarily enforced through private lawsuits.

For broader layoff compliance context—including planning steps HR should take—see SwiftSDS’s guide to a legal layoff.

Is there an “MA WARN Act” (Mass WARN Act)?

Massachusetts does not currently have a separate statewide “Mass WARN Act” statute equivalent to states like New York or California. In practice, when HR teams refer to the “MA WARN Act,” they usually mean:

The federal WARN Act requirements as applied in Massachusetts, and/or
Massachusetts-specific workforce agency practices and rapid response coordination (which often occur when WARN thresholds are met)

Because WARN requirements vary significantly by jurisdiction, multi-state employers should also review WARN notices by state obligations. For example, New York has a true state-level WARN law—see the discussion of WARN Act New York below.

If you also manage postings and notices in Massachusetts locations, SwiftSDS maintains dedicated pages for Massachusetts (MA) Posting Requirements and city/county requirements such as Boston, Suffolk County, MA Posting Requirements and Worcester County, MA Posting Requirements.

Who must comply with the federal WARN Act?

Under the federal WARN Act, covered employers generally include:

Private for-profit employers and nonprofit employers with 100 or more employees, excluding part-time employees (as defined under WARN), or
Employers with 100 or more employees who collectively work at least 4,000 hours per week (excluding overtime)

This coverage test is technical. If you are close to the threshold, confirm headcount and hours carefully before assuming WARN does—or does not—apply.

When is a WARN notice required?

A federal WARN notice is generally required when a covered employer orders a plant closing or mass layoff that causes an employment loss at a “single site of employment,” during any 30-day period, of:

Plant closing (federal WARN threshold)

A plant closing typically triggers WARN if it results in employment loss for 50 or more employees at a single site of employment during a 30-day period (not counting part-time employees).

Mass layoff (federal WARN threshold)

A mass layoff (not a plant closing) generally triggers WARN if it results in employment loss at a single site for either:

500 or more employees, or
50–499 employees if they make up at least 33% of the employer’s active workforce at that site (again, excluding part-time employees in the count)

The required timing: 60 days

Federal WARN generally requires at least 60 days’ advance written notice.

What is “employment loss” under WARN?

WARN is triggered by “employment loss,” which generally includes:

Termination other than for cause, voluntary departure, or retirement
A layoff exceeding 6 months
A reduction in hours of work of more than 50% during each month of a 6-month period

Because “employment loss” is defined terms-of-art, document your assumptions (especially for furloughs, temporary layoffs, and reductions in hours).

Who must receive the WARN notice? (Your “duty to warn letter” list)

If WARN applies, the employer must deliver a written notice to specific recipients. Your “duty to warn letter” distribution list generally includes:

Affected employees (or their union representative, if represented)
The State dislocated worker unit (the state rapid response / workforce agency)
The chief elected official of the local government where the site is located

HR best practice: build a standardized WARN checklist that includes who receives the notice, the delivery method, proof of service, and internal approvals.

What must a WARN notice include?

Federal regulations outline required content (see WARN regulations at 20 CFR Part 639). While the exact content differs depending on whether employees are represented by a union, WARN notices commonly include:

Name/address of the employment site and contact information
Whether the action is permanent or temporary
Expected date of the first separation and the schedule for separations
Job titles and number of affected employees in each job classification
Bumping rights (if any)
Union information (if represented)

Actionable tip: include a single internal point of contact (HR or legal) and ensure the separation schedule is consistent across employee communications, vendor notifications, and any public statements.

WARN notices by state: Why Massachusetts employers still need to pay attention

Even though Massachusetts does not have a standalone “mass WARN act,” employers with multi-state operations often run into state mini-WARN laws that impose:

Longer notice periods (e.g., 90 days)
Lower headcount thresholds
Additional notice recipients
Broader definitions of covered events

Example: WARN Act New York (NY WARN)

New York has its own state WARN law with requirements that are often more stringent than federal WARN. If you have employees in New York—or a reduction in force that touches NY worksites—review SwiftSDS guidance and postings at New York (NY) Posting Requirements to avoid missing state-specific obligations.

For employers expanding compliance programs across multiple jurisdictions, SwiftSDS also tracks related rules like California employment laws.

Massachusetts compliance isn’t just WARN: Don’t miss required workplace notices

Layoffs and restructurings often expose gaps in broader compliance—especially required postings and employee notices. In Massachusetts, employers commonly must maintain up-to-date state posters, such as:

And for federal poster compliance during workforce changes, confirm you’re current on Employee Rights Under the Fair Labor Standards Act.

A broader refresher on core employee protections is also helpful for managers involved in reductions in force—see 5 rights of workers.

Practical steps for HR: How to reduce WARN risk in Massachusetts

1) Determine whether you have a “single site of employment”

Remote work, traveling employees, and multi-building campuses can complicate this analysis. Map affected employees to sites early.

2) Count affected employees correctly

WARN counting rules exclude certain part-time employees and require careful categorization. A small counting error can change whether notice is required.

3) Build a compliant notice timeline

Start with the 60-day rule, then verify whether any state mini-WARN laws apply (especially if you have cross-border impacts).

4) Coordinate messaging across compliance areas

WARN notices, separation agreements, unemployment communications, and internal FAQs must align. Inconsistent dates are a common litigation trigger.

5) Document exceptions carefully (if used)

Federal WARN includes limited exceptions (e.g., faltering company, unforeseeable business circumstances, natural disaster). These are fact-specific and still require notice “as soon as practicable,” with an explanation.

FAQ: MA WARN Act and WARN notices

Does Massachusetts have a state WARN law?

Massachusetts does not currently have a standalone mini-WARN statute like New York. Most “MA WARN Act” questions are answered by applying the federal WARN Act and its regulations (20 CFR Part 639) to Massachusetts worksites.

How much notice is required under the WARN Act?

Federal WARN generally requires 60 days’ advance written notice to affected employees (or their union), the state dislocated worker unit, and the local chief elected official.

Are small employers exempt from WARN?

Often, yes—federal WARN generally applies to employers with 100+ employees (using WARN’s counting rules). However, multi-state operations may be subject to state mini-WARN laws with different thresholds, so review WARN notices by state if your reduction affects other jurisdictions.

SwiftSDS helps employers maintain compliant labor law postings and stay aligned with evolving federal and state requirements. For Massachusetts-specific posting rules, visit Massachusetts (MA) Posting Requirements.

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