- The exam has 160 questions (135 scored, 25 unscored) in a 3-hour, closed-book format.
- Total initial cost is $550: a $150 application fee plus a $400 exam fee.
- Clinical Practice and Case Management is the largest domain at 45 scored items.
- Eligibility requires an RN license, a bachelor's degree or higher, and 3,000 occupational health nursing hours in five years.
COHN-S At a Glance
This is a one-page reference for the Certified Occupational Health Nurse - Specialist (COHN-S) credential issued by the American Board for Occupational Health Nurses, Inc. (ABOHN). If you want the long-form breakdown of any line item below, pair this sheet with the full COHN-S Study Guide 2026 for a first-attempt strategy, or check What Is COHN-S Certification? if you're still deciding whether to apply.
| Item | Detail |
|---|---|
| Certifying body | ABOHN (American Board for Occupational Health Nurses, Inc.) |
| Testing provider | Assessment Systems Corporation (ASC) |
| Delivery options | Test center or live remote proctoring via MonitorEDU |
| Question count | 160 total: 135 scored, 25 unscored, four-option multiple choice |
| Time limit | 3 hours, closed-book, no scheduled breaks |
| Total initial fees | $150 application + $400 exam = $550 |
| Testing eligibility window | 120 days once approved |
| Passing standard | Angoff-based criterion-referenced standard |
| 2025 reported pass rate | 83% (94 of 113 examinees) |
| Recertification cycle | Five years, $150 annual maintenance |
Who Administers the COHN-S
ABOHN owns the credential end to end - eligibility review, the blueprint, and recertification. Exam delivery itself is handled by Assessment Systems Corporation (ASC), which offers candidates a choice between an in-person test center and live remote proctoring through MonitorEDU. That flexibility matters for shift-working occupational health nurses who can't always travel to a fixed testing site.
If you're new to the credential structure entirely, start with What Is COHN-S? or the shorter explainer What Does COHN-S Stand For? before diving into logistics.
Eligibility Snapshot
ABOHN screens applicants before they're allowed to schedule the exam. You need all three of the following:
- A current, unrestricted RN license (or recognized international equivalent)
- A bachelor's degree or higher, in any field of study
- 3,000 hours of occupational health nursing practice within the preceding five years
Qualifying occupational or environmental health education can offset part of the required practice hours, so document coursework carefully when you apply. For the full eligibility walkthrough, including how hours are counted and verified, see COHN-S Requirements 2026.
Key Takeaway
Gather RN license verification, degree transcripts, and detailed practice-hour documentation before you submit - incomplete applications delay your 120-day testing window from ever starting.
The Four Domains, Fast
The current blueprint took effect September 1, 2024, following a 2023 practice analysis, and it allocates scored items across four content areas. Clinical Practice and Case Management is the heaviest domain, so it deserves the largest share of your review time. For a deep dive into subtopics and sample question logic in each area, see the COHN-S Exam Domains 2026 guide.
Domain 1: Clinical Practice and Case Management (45 scored items)
The largest domain. Covers hands-on assessment, treatment, and follow-up of workplace injuries and illnesses, plus coordinating care across providers.
- Injury/illness assessment and triage decisions
- Case management across return-to-work timelines
- Health surveillance and screening protocols
Domain 2: Risk and Compliance (32 scored items)
Focuses on regulatory frameworks and hazard controls that occupational health nurses must apply on the job.
- OSHA-related recordkeeping and reporting concepts
- Hazard identification and exposure risk assessment
- Regulatory compliance documentation
Domain 3: Program Management and Quality Assurance (30 scored items)
Tests your ability to design, run, and evaluate occupational health programs.
- Wellness and prevention program design
- Quality assurance metrics and outcome tracking
- Data-driven program evaluation
Domain 4: Operations and Business Management (28 scored items)
The smallest domain but still worth nearly a fifth of scored items - covers the business side of running an occupational health function.
- Budgeting and resource allocation
- Staffing and vendor management
- Ethical and legal business considerations
Fees and Registration Mechanics
Initial certification costs $550 total: a $150 application fee and a $400 examination fee. Once ABOHN approves your eligibility, you have a 120-day window in which to schedule and sit for the exam through ASC. Miss that window and you'll need to re-enter the process, so schedule your test date as soon as approval lands. For a full cost breakdown, including recertification fees, see COHN-S Certification Cost 2026.
Exam Day Format Rules
The COHN-S exam is closed-book. The 2026 candidate handbook, revised in March 2026, prohibits scheduled breaks during the 3-hour session, so plan your pacing across all 160 questions without assuming a pause. With 135 scored and 25 unscored questions blended together and indistinguishable during the test, you should treat every item as if it counts.
- 160 four-option multiple-choice questions
- 3-hour time limit, no breaks
- Delivered at a test center or via MonitorEDU live remote proctoring
- Reference list in effect September 1, 2026 through August 31, 2027 governs any allowed source material policies for that testing cycle
If you're weighing how tough this format actually feels in practice, read How Hard Is the COHN-S Exam? for a difficulty breakdown by domain and question style.
Passing Standard
ABOHN sets the passing standard using an Angoff-based, criterion-referenced method - your score is measured against a fixed competency bar, not against how other candidates performed on your test date. ABOHN's most recently reported annual result was an 83% pass rate for 2025 (94 of 113 examinees), a dated cohort statistic rather than a promise about your individual outcome. For more on how the cutoff is set and what it means for your prep, see COHN-S Passing Score 2026 and COHN-S Pass Rate 2026.
Key Takeaway
Because scoring is criterion-referenced, your target is mastering the content in each domain - not out-competing other test takers. Focus study time on the largest domains first.
Recertification Cycle
COHN-S certification runs on a five-year cycle. To maintain it, you need:
- Continued current RN licensure
- $150 in annual maintenance payments
- 50 occupational health nursing continuing-education hours over the cycle
- 3,000 occupational health nursing practice hours over the cycle
Track these requirements from day one of certification rather than scrambling in year five - CE hours and practice hours both accrue over time and can't be backfilled easily. See COHN-S Certification for how initial and ongoing requirements connect.
Final-Week Review Plan
In the last week before your test date, allocate review time in proportion to scored-item weight rather than evenly across domains. This isn't a generic study framework - it's mapped directly to the COHN-S blueprint.
Clinical Practice and Case Management
- Drill injury assessment and case-management scenarios (45 scored items, the largest domain)
- Review return-to-work and health surveillance concepts
Risk and Compliance
- Review regulatory and recordkeeping concepts (32 scored items)
- Practice hazard-assessment style questions
Program Management and Quality Assurance
- Review program design and QA metrics (30 scored items)
Operations and Business Management
- Cover budgeting, staffing, and vendor topics (28 scored items)
Full-length practice and timing
- Take timed, mixed-domain practice sets to simulate the no-break, 3-hour format
- Review weak areas identified across all four domains
Run your final timed practice sessions at our COHN-S practice test platform to get comfortable with the pacing before test day, since there's no scheduled break to reset during the real exam. For a more detailed week-by-week plan spanning your entire prep timeline, not just the final week, see the COHN-S Study Guide 2026.
Who Hires COHN-S Nurses
Employers seeking COHN-S-credentialed nurses typically operate in manufacturing, energy, logistics, and other industries with structured occupational health programs - roles that span clinical case management, compliance oversight, and program leadership, matching the exam's four domains. If you're exploring career paths and typical employers, browse COHN-S Jobs, and if you're evaluating the credential's long-term value before committing to the fees and hour requirements, read Is the COHN-S Certification Worth It? alongside the COHN-S Salary Guide 2026.
Building Your Prep Calendar
Because your 120-day testing eligibility window starts ticking as soon as ABOHN approves your application, treat that approval date as your prep-schedule anchor point, not your application-submission date. Map out when you'll finish each domain, when you'll sit for full-length timed practice, and when you'll schedule your actual test slot through ASC. For a broader look at testing windows and deadlines across the year, see COHN-S Exam Dates 2026. And if you're not sure the credential fits your career path at all, What Is COHN-S Certification? lays out the basics before you invest the $550 in fees.
Whichever calendar you build, revisit it weekly against actual progress. Candidates who track domain-by-domain readiness against the 45/32/30/28 scored-item split tend to walk into test day with a clearer sense of where their remaining risk sits, rather than a vague feeling of "mostly ready."
Frequently Asked Questions
There are 160 four-option multiple-choice questions total: 135 are scored and 25 are unscored pretest items. You won't know which is which during the exam, so treat every question as scored.
Initial certification costs $550: a $150 application fee plus a $400 examination fee, both paid to ABOHN as part of the eligibility and scheduling process.
No. The 2026 candidate handbook, revised in March 2026, prohibits scheduled breaks during the exam session, so plan your pacing across all 160 questions accordingly.
Start with Clinical Practice and Case Management, since it carries the most scored items at 45. Follow with Risk and Compliance (32), Program Management and Quality Assurance (30), and Operations and Business Management (28).
You have 120 days from eligibility approval to schedule and complete your exam through ASC, at a test center or via MonitorEDU live remote proctoring.
Certification is valid on a five-year cycle. To maintain it, you'll pay $150 annually, keep an active unrestricted RN license, and log 50 continuing-education hours plus 3,000 occupational health nursing practice hours across the cycle.