Articles · Special Exposure Cohort

The Special Exposure Cohort: when the government presumes your cancer came from the work.

For certain worksites and years — including periods at the Nevada Test Site — Congress and NIOSH have ruled that workers qualify more easily: no dose reconstruction, no proving your exposure case by case.

Reviewed by Alara’s Director of Nursing, RN · July 2026

What an SEC does.

Normally, a radiation claim requires dose reconstruction — a scientific estimate of your exposure. An SEC removes that step: if you worked at a covered site during the covered window for the required days, and you have one of the 22 specified cancers, the link to the work is presumed.

  • You prove the employment (where and when).
  • You prove the diagnosis (one of the specified cancers).
  • The causation is presumed — that is the whole point.

New cohorts keep being added. A claim denied before a cohort existed can be reopened once your worksite and years are covered. How reopening works →

The Nevada Test Site.

The Test Site has SEC classes covering defined periods of its operation — which is why so many Test Site families qualify without dose reconstruction. Which years, which cancers, and what the benefit is worth: the Nevada Test Site guide →

Common questions.

How do I know if my site and years are covered?

The Resource Center can check your employment against current SEC classes at no charge: (702) 697-0841. NIOSH publishes the full class list.

What if my cancer is not one of the 22?

You may still qualify through dose reconstruction under Part B, or under Part E for toxic exposure. A denial under one path does not close the others.

Sources: NIOSH, Office of Compensation Analysis and Support · U.S. Department of Labor, DEEOIC.

Worked at the Test Site during a covered window?

A case review maps your years and diagnosis against the cohort rules and tells you what the evidence supports.

Start a case review Or call (702) 814-9630
Alara helps you understand and reach benefits you may already be entitled to. It does not replace the Department of Labor, your Resource Center, your physician, or any federal agency. Nothing here is legal advice or a coverage or eligibility determination.