- ABOHN reports a 65% COHN pass rate for 2025, but also lists 57/85, and the discrepancy is unresolved.
- The exam has 160 multiple-choice questions: 135 scored and 25 unscored pretest, over 3 hours, closed-book.
- Scored items split 72/40/23 across three domains; Clinical Practice and Case Management is the largest.
- Total cost is $550 ($150 application plus $400 exam), so a failed attempt is expensive.
What the Published Numbers Say
If you are weighing whether to sit for the Certified Occupational Health Nurse credential, the pass rate is probably one of the first things you looked up. The American Board for Occupational Health Nurses (ABOHN) publishes certification statistics on its website, and that is the only source worth trusting for this question. Third-party forums, recruiter blogs, and social media posts routinely repeat numbers that nobody can trace back to the certifying body.
Here is the honest summary of what ABOHN's published data offers for the 2025 cycle: a reported pass rate of 65%, alongside a second set of figures listed as 57/85. The board's own page does not fully reconcile the two. That is not a reason to panic, but it is a reason to be careful about quoting any single number as settled fact. This article walks through what we can say with confidence, what remains ambiguous, and how to use the data to plan your preparation rather than to predict your fate.
For a broader sense of exam difficulty beyond one statistic, see our companion piece, How Hard Is the COHN Exam? Complete Difficulty Guide 2026.
The 65% vs. 57/85 Discrepancy
Candidates who read ABOHN's statistics page closely notice something awkward. The board reports 65% for 2025, yet the same page also lists 57/85. Those figures do not obviously describe the same thing, and the board does not explain the relationship between them on the page itself.
What does this mean practically? It means the safest posture is to prepare as though the exam is a genuine professional-competence hurdle, because it is. A pass rate in the neighborhood the board reports signals that a meaningful share of well-qualified candidates do not pass on a given attempt. These are, after all, nurses who already hold an RN and have accumulated substantial occupational health experience before they are even allowed to apply.
Our dedicated article on COHN Passing Score 2026: Exactly What You Need to Pass explores how scoring works in more depth, which matters because a pass rate is only meaningful when you understand what "passing" actually requires.
How the Passing Standard Is Set
The COHN uses an Angoff-based passing standard. In plain terms, a panel of subject-matter experts reviews exam items and estimates how a minimally competent occupational health nurse would perform on each one. Those judgments are aggregated into a cut score that represents the minimum acceptable level of competence.
Two consequences follow, and both matter for how you interpret pass-rate data:
- You are measured against a benchmark, not against other candidates. You do not need to outperform anyone. If every candidate in a testing window demonstrated minimum competence, in principle every one could pass.
- Pass rates can move year to year. Because the standard is anchored to competence rather than to a fixed percentile, shifts in who tests, how well-prepared they are, and how the exam form is constructed can all nudge the rate up or down.
This is also why a single year's figure, even a clean one, is a weak predictor of your personal outcome. Your result depends on your command of the content, not on the cohort average.
Exam Format That Shapes Outcomes
The structure of the COHN exam explains a lot about why preparation, not raw experience alone, drives results. Here is the verified format, delivered through Assessment Systems Corporation (ASC) either at a testing center or by MonitorEDU live remote proctoring:
| Feature | COHN Detail |
|---|---|
| Question type | Multiple-choice |
| Total questions | 160 |
| Scored questions | 135 |
| Pretest (unscored) questions | 25 |
| Time allowed | 3 hours |
| Reference materials | Closed-book |
| Delivery | Testing center or MonitorEDU live remote |
Two details deserve emphasis. First, 25 of the 160 questions are unscored pretest items that ABOHN is trialing for future exams. You will not know which ones they are, so you must treat every question as if it counts. Second, the exam is closed-book. Occupational health nurses are used to consulting regulations, guidelines, and workplace policies in daily practice, but on exam day you must retrieve standards, definitions, and decision frameworks from memory.
Roughly 160 questions in 3 hours leaves just over a minute per item, which is workable for well-prepared candidates but punishing if you stall on scenario-heavy questions. Pacing is a real variable in outcomes.
Who Sits the Exam
Pass-rate figures reflect a self-selected, pre-screened population. To apply, candidates need an RN license (or an international equivalent) plus 3,000 hours of occupational health practice within the previous five years. Specified education alternatives exist but require approval. Because every candidate has substantial field experience, the pool is not made up of newcomers who are guessing at what occupational health nursing involves.
That context cuts two ways. On the encouraging side, your day-to-day practice gives you a real foundation. On the cautionary side, experienced nurses sometimes fail because their experience is narrow: a nurse deep in clinic-based injury care may be thin on program management, or a nurse who handles compliance paperwork may be rusty on clinical case management. The exam rewards breadth across all three domains.
For full eligibility mechanics, see COHN Requirements 2026: Eligibility, Prerequisites & How to Qualify. And if you are still orienting yourself to the credential, What Is COHN Certification? gives the background.
Where Points Are Won: The Three Domains
ABOHN's handbook allocates scored items across the three content domains as 72, 40, and 23 questions. These are item counts, not percentage labels, and together they account for the 135 scored questions. Understanding this allocation is the single most useful way to turn pass-rate anxiety into a concrete plan.
Domain 1: Clinical Practice and Case Management (72 scored items)
The largest domain by a wide margin, covering more than half of the scored exam. This is where the bulk of your score is earned or lost.
- Assessment and management of work-related injuries and illnesses
- Case management, including return-to-work and modified-duty decisions
- Coordination among employees, employers, providers, and payers
- Clinical decision-making in occupational settings
Domain 2: Risk and Compliance (40 scored items)
Regulatory knowledge and hazard-focused thinking that occupational health nurses must apply in worksite scenarios.
- Workplace health and safety regulations and recordkeeping obligations
- Hazard recognition, exposure assessment, and prevention strategies
- Surveillance and compliance responsibilities
- Legal and ethical considerations in the occupational setting
Domain 3: Program Management and Quality Assurance (23 scored items)
The smallest domain, but still worth roughly one in six scored questions.
- Planning, implementing, and evaluating occupational health programs
- Quality improvement and outcome measurement
- Resource management and stakeholder communication
Because Domain 1 carries 72 of 135 scored items, a candidate who is merely adequate there but strong elsewhere is taking a real risk. Conversely, neglecting Domain 3 because it is small can still cost you around 23 questions. For a deeper look at what each area covers, read COHN Exam Domains 2026: Complete Guide to All 3 Content Areas.
Key Takeaway
Do not let the "smaller" domains lull you. Domain 1 dominates the score, but Domains 2 and 3 together make up 63 scored questions. A solid pass usually comes from competence across the board, not from excelling in one area.
What a Miss Costs You
Pass rates matter partly because the financial stakes are real. ABOHN's published fees are a $150 application fee plus a $400 examination fee, for $550 total. Missing the mark means the time, the money, and the scheduling friction of trying again, on top of the emotional cost of a setback after months of preparation.
That arithmetic argues for investing in preparation up front. A modest outlay on quality practice questions and review materials is small compared with the cost of a second attempt. For the full pricing picture, including ongoing costs, see COHN Certification Cost 2026: Complete Pricing Breakdown. And if you are asking whether the investment pays off at all, Is the COHN Certification Worth It? Complete ROI Analysis 2026 tackles that question directly.
A Domain-Weighted Study Sequence
Rather than a generic plan, here is a sequence tied directly to the 72/40/23 allocation. Adjust the timing to your own schedule; the logic is what matters.
Build the Clinical Core (Domain 1)
- Work through injury and illness management and case management scenarios
- Practice return-to-work and modified-duty reasoning
- Do timed sets of scenario questions to build pacing
Lock Down Risk and Compliance (Domain 2)
- Memorize regulatory frameworks and recordkeeping obligations, since the exam is closed-book
- Review hazard recognition and exposure-control logic
Cover Program Management and Quality (Domain 3)
- Review program planning, evaluation, and quality improvement concepts
- Connect metrics and outcomes to program decisions
Integrate and Simulate
- Take full-length 160-question practice sessions in 3 hours
- Revisit your weakest domain based on results
Front-loading Domain 1 makes sense because it holds the most points and because its scenario-based style takes the longest to master. For a fuller methodology, see the COHN Study Guide 2026: How to Pass on Your First Attempt, and keep the COHN Cheat Sheet 2026: One-Page Review of Must-Know Facts handy for final review. When you are ready to test yourself under realistic conditions, our COHN practice test lets you check readiness domain by domain.
How to Read Pass-Rate Statistics Wisely
A few principles will keep you from over- or under-reacting to the numbers.
A pass rate is a population statistic, not a personal forecast
Your probability of passing depends on your preparation and your match to the exam content, not on the average. A well-prepared candidate who has worked through all three domains is not "65% likely" to pass in any meaningful sense.
Beware of precision you cannot verify
Given the unresolved 65% versus 57/85 discrepancy, any source quoting a crisp, confident number without citing ABOHN should be treated skeptically. Go to the primary source and note the date of the figures.
Use the data to set effort, not to induce dread
The takeaway from a pass rate that is neither trivially high nor alarmingly low is straightforward: this is a real exam that rewards real preparation. Plan for it the way you would plan for any professional licensing hurdle.
Look at the whole career picture
Many candidates pursue the credential for career reasons, such as eligibility for specific roles or stronger standing with employers. If that is your motivation, pair the pass-rate question with research on COHN jobs and our COHN Salary Guide 2026: Complete Earnings Analysis, so you understand what the credential can do for you after you pass.
If you are still deciding on a testing window, check COHN Exam Dates 2026: Testing Windows, Deadlines & Scheduling to plan your preparation backward from a realistic date.
Frequently Asked Questions
ABOHN reports 65% for 2025, but its statistics page also lists 57/85, and the relationship between the two is unresolved. Check the board's certification statistics page directly for the most current and authoritative figures.
No. The exam uses an Angoff-based passing standard, which sets a competence benchmark rather than ranking candidates against each other. Your result depends on meeting that standard.
The exam has 160 multiple-choice questions, but only 135 are scored. The other 25 are unscored pretest items, and you cannot tell which is which, so treat every question as important.
Clinical Practice and Case Management is the largest, with 72 of the 135 scored items. Risk and Compliance accounts for 40 and Program Management and Quality Assurance for 23, so all three domains still matter.
The published fees are a $150 application plus a $400 examination fee, totaling $550. Confirm current retake mechanics and fees with ABOHN, since policies can change between handbook editions.
The bottom line on the COHN pass rate is that the data is useful but imperfect. ABOHN's 65% figure for 2025, paired with the unexplained 57/85 listing, tells you the exam is a genuine challenge without telling you your own odds. Prepare across all three domains, weight your time toward Clinical Practice and Case Management, and verify any statistic against the official ABOHN source before you rely on it.