What Is COHN?

COHN Defined: Certified Occupational Health Nurse

COHN stands for Certified Occupational Health Nurse. It is a professional certification for registered nurses whose practice centers on the health, safety, and well-being of workers and working populations. If you have landed here after seeing the same four letters attached to other credentials in unrelated fields, note that this site and this article are concerned only with the nursing certification for occupational health. Everything below applies to that credential and nothing else.

Occupational health nursing sits at the intersection of clinical care, public health, regulatory compliance, and business operations. A COHN may treat a work-related injury in the morning, review an exposure monitoring report at midday, and present an absence-management trend to leadership in the afternoon. The certification exists to verify that a nurse can do all of that competently, not just the bedside portion. For a deeper look at the terminology, see our explainer on what COHN stands for and the companion piece on what COHN certification is.

Who Awards the Credential and How the Exam Is Delivered

The credential is awarded by the American Board for Occupational Health Nurses, Inc., commonly abbreviated ABOHN. The board sets eligibility rules, publishes the candidate handbook, establishes the passing standard, and manages recertification. The current handbook referenced for this article is the March 2026 edition, and candidates should always confirm requirements against the latest version on the ABOHN website, since policies, fees, and processes can change between editions.

Test delivery is handled by Assessment Systems Corporation (ASC). Candidates can sit for the exam at a testing center or take it through live remote proctoring using MonitorEDU. Choosing between the two is a practical decision: a testing center removes home-technology risk, while remote delivery removes travel. Whichever you choose, treat the logistics as part of your preparation rather than an afterthought.

Who Actually Works as a COHN

Occupational health nurses are found wherever employers have a stake in workforce health. Typical settings include:

• Manufacturing and heavy industry, where injury prevention, hazard exposure, and return-to-work planning dominate the role.
• Corporate and office environments, where wellness programming, ergonomics, and absence management are common priorities.
• Healthcare systems, where employee health departments manage immunizations, exposures, and workers' compensation cases for their own staff.
• Utilities, transportation, and logistics, where fitness-for-duty and medical surveillance programs matter.
• Government agencies and the military-adjacent civilian workforce, including public-sector employee health programs.
• Consulting and third-party occupational health clinics, serving multiple employers under contract.

Because the work spans clinical judgment and organizational management, the certification attracts nurses who want to move beyond purely clinical roles into case management, program leadership, or compliance-oriented positions. Our page on COHN jobs expands on titles and employer types, and the COHN salary guide covers earnings considerations.

Eligibility: Licensure Plus Practice Hours

The eligibility structure has two pillars. First, you need an active registered nurse license, or an international equivalent. Second, you need 3000 hours of occupational-health practice within the previous five years. That second requirement is what separates this certification from entry-level credentials: it assumes you have been doing the work, not just studying it.

The handbook also describes specified education alternatives, and those routes require approval from the board. If you are not sure whether your background fits the standard hours pathway or an alternative, resolve that question before you pay anything or build a study plan. A clear walkthrough of prerequisites is available in our guide to COHN requirements.

What the Exam Looks Like

The exam consists of 160 multiple-choice questions delivered over three hours. Of those 160 items, 135 are scored and 25 are pretest items used by the board to evaluate new questions for future forms. You will not know which items are unscored, so every question deserves your full effort. The exam is closed-book: no reference materials, no notes.

Three hours for 160 questions works out to a little over a minute per item, which is workable but leaves little room for lingering. Scenario-style questions that ask you to prioritize actions, interpret a situation in a workplace context, or identify the most appropriate next step will consume more time than straightforward recall items, so pacing matters. For a frank assessment of difficulty, read how hard the COHN exam is.

The Three Domains in Detail

The exam content is organized into three domains. The official allocation of the 135 scored items is 72, 40, and 23 across the three domains respectively. These are item counts, not percentage labels, and they tell you where the weight sits. Clinical Practice and Case Management is by far the largest. Our full breakdown lives in the COHN exam domains guide.

Fees and Registration Mechanics

The cost structure is straightforward: a $150 application fee and a $400 examination fee, for a total of $550. Budget for these two payments plus whatever preparation materials you choose. A fuller accounting, including ongoing maintenance costs, appears in the COHN certification cost breakdown.

1. Confirm eligibility against the current handbook, including your RN status and practice-hour documentation.
2. Submit the application with the $150 fee to ABOHN.
3. Pay the $400 examination fee once your application is processed.
4. Schedule your delivery method, choosing between an ASC testing center and MonitorEDU live remote proctoring.
5. Sit for the exam within your authorized testing period.

Testing windows and deadlines are covered separately in our COHN exam dates article. Always verify the current schedule directly with ABOHN before committing to a plan.

Passing Standard and the Reported Numbers

ABOHN uses an Angoff-based passing standard. In plain terms, subject-matter experts judge how a minimally competent candidate would perform on each item, and those judgments are aggregated to set the cut point. This means the passing standard is tied to a defined competence threshold rather than a fixed curve against other test-takers.

Here is where candidates should be careful. ABOHN reports a figure of 65% for 2025, but it also lists 57/85 in its statistics, and the relationship between those numbers is an unresolved discrepancy. It is not clear from the published material alone how the two figures should be reconciled, so this article does not claim to know which is the operative pass rate or cut score. Rather than guess, treat the published statistics as something to verify directly with the board. Our pages on the COHN pass rate and COHN passing score discuss how to interpret what is and is not known.

Sequencing Your Preparation Around the Domains

You do not need an elaborate system. What you do need is a sequence that reflects how the exam is weighted. Because Domain 1 carries 72 of 135 scored items, it deserves the longest runway and the most practice questions. The sketch below is one reasonable way to allocate a roughly six-week window; adjust it to your own strengths and the hours you can realistically protect. The COHN study guide offers a fuller framework.

When you are ready to test yourself, use the COHN practice tests to rehearse the question style and timing, and keep the COHN cheat sheet handy for last-pass review of must-know facts. Since the exam is closed-book, active recall beats rereading.

Keeping the Credential Active

Certification is not permanent. COHN operates on a five-year recertification cycle. To recertify, you need to maintain active RN status, accumulate 3000 practice hours, and complete 50 related continuing nursing education (CNE) hours. There is also an annual maintenance/recertification fee of $150.

The practical implication is that your day-to-day job doubles as recertification preparation, as long as you keep records. Log your hours as you go and save CNE certificates in one place, rather than reconstructing five years of activity at the deadline. Details are on the ABOHN recertification page and summarized in the COHN certification overview.

Is It Worth Pursuing?

Whether the credential pays off depends on your goals. For nurses aiming at occupational health leadership, case-management roles, or employer-facing program positions, the certification signals verified specialty competence in an area where many general nurses have limited formal training. For nurses who intend to remain in a single clinical niche unrelated to workplace health, the case is weaker. We work through the trade-offs in whether the COHN certification is worth it, and you can explore the learning side in our overview of COHN training.

A few honest points to weigh: the 3000-hour requirement means you must already be established in the field, so the credential validates experience rather than replacing it; the $550 upfront cost is modest relative to many professional certifications but comes with ongoing annual fees and CNE obligations; and employer recognition varies by industry and region. Check job postings in your target market to see how often certification appears as a preference or requirement.

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