The WARN numbers on the Layoff Atlas registry — 699 notices covering 65,791 reported workers in the current 90-day window, updated October 23, 2026 — describe only the layoffs that federal law requires employers to announce in advance. But which layoffs qualify is decided by a set of coverage rules most workers have never read. The most important one is the 100-employee rule, and it shapes everything about how WARN data looks.

Only large employers have to file at all

The federal WARN Act applies only to employers with 100 or more full-time employees. A company with 99 full-time workers can eliminate every position tomorrow and owe no federal notice at all. That is the single largest coverage gap in the system — and a big reason the registry can never be read as a census of American layoffs. When small and mid-size employers cut staff, no WARN notice is generated, so those losses simply never enter the data.

Part-time workers usually don't count toward 100

The 100-worker headcount excludes part-time employees, which the law defines as workers who average fewer than 20 hours per week or who have worked fewer than six of the last twelve months. An employer with 200 people on the roster may still be exempt if half of them are part-time by that definition. The full-time-equivalent line matters for workers too: if you work part-time, your job may not be counted when the company decides whether it owes notice.

A layoff has to be big enough — at one site

Even covered employers only owe notice for qualifying events at a single site of employment:

  • Plant closing: 50 or more workers at one site lose their jobs in a 30-day period.
  • Mass layoff: 500 or more workers at one site lose their jobs — or 50 to 499 workers, if they make up at least one-third of the active full-time workforce at that site.
  • The 90-day rule: layoffs split across a 90-day window count together, unless the employer can show the phases are separate and distinct. A company cannot dodge the law by laying off 40 people a month for three months.

This is why a 45-person layoff at a 300-person site generates no notice, while the same layoff at a 120-person site might. Geography matters: layoffs spread across many sites can each fall below the threshold even when the company-wide total is large.

Who falls through the gap

Put the rules together and whole categories of job loss are invisible to WARN data: workers at companies under 100 full-time employees, cuts below the 50-worker/33-percent thresholds, and layoffs spread thinly across sites. Remote workers add another wrinkle — the law's "single site of employment" language was written for factories and offices, and coverage for distributed teams depends on how the employer's home base is defined.

A few states close part of the gap. So-called mini-WARN laws lower the thresholds — California, for example, covers employers with 75 or more workers, counting part-timers — which is why richer WARN data comes out of some states than others. Where state law is thinner, the registry is thinner too.

Reading the registry with the rule in mind

When you see the heaviest upcoming week on the calendar — 8,744 workers scheduled effective the week of November 13, or 8,520 the week of October 30 — remember these are reported plans, not confirmed job losses, and they are reported plans from large employers only. The real economy-wide layoff total is larger than the WARN window shows, because everything below the coverage line never gets a notice.

Knowing the 100-employee rule also answers the most common worker question: "My employer laid me off with no warning — was that legal?" Often, yes — if the employer was under the threshold, your hours classified you as part-time, or the cut was too small to trigger the law. That is the floor the WARN Act built in 1988, and every WARN number ever published sits on top of it.

Data source: Layoff Atlas