These handbooks provide information needed to apply and prepare for the COHN and COHN-S examinations. Please click on the images to download the handbooks.

Each handbook includes the following: eligibility requirements, examination policies, examination application, test blueprint, core content areas, sample questions, and study references. Please retain this handbook after applying for the examination. It is extremely useful when studying for the examination.

PLEASE NOTE: There are different education qualifications for the COHN and COHN-S examinations.  HOWEVER, if you qualify for both examinations, just having a higher degree does not necessarily mean you should take the examination with the higher degree qualifications.  Please review the examinations Blue Prints/Test Specifications in BOTH HANDBOOKS before deciding on which examination to take.  It is HIGHLY RECOMMENDED that you choose the examination that fits your practice, not your level of education.

cohn handbook

cohn-s handbook


What are some suggestions to prepare for the certification exam?

        Recently certified occupational health nurses (OHN) identified these tips to prepare for the exam: 

  • Begin a regular study plan about 6 months prior to when you plan to take the exam.
  • Studied 3-5 days a week for an average of 9-10 hours weekly.
  • The OHNs found helpful materials included:
    • AAOHN Core Curriculum.
    • AAOHN Exam Blueprints.
    • ABOHN Self-Assessment Tests (CSATs).
  • 44% indicated a certification review course was helpful

Please note:  Although the AAOHN Core Curriculum and on-line classes provide an excellent review of the aspects of OHN practice, it is not intended as an exclusive source of information for the exams.

Although ABOHN cannot endorse nor recommend any specific course(s) for preparation, we can provide industry information that may help you in studying for the COHN and/or COHN-S:

Ten Test Taking Tips

  1. Focus on the topics in the exam blueprint.  Download the handbook of the credential (COHN, COHN-S, CM), review the domains of the test blueprints, and review the reference list.  The exams cover OHN practice across industries. 
  2. Review the main domains of the exam.  Review all domain areas because if you overly focus on one, you may neglect others.  However, you may want to spend more time on areas where you noted knowledge gaps when reading the exam blueprint.
  3. Know the format of the exam.  The COHN and COHN-S exams have 160 test questions, and you are allowed 3 hours to take the computer-based exam.  This includes 25 “pre-test” items that do not count towards your score, but you will not know which questions count.  For the CM exam, there are 110 questions of which 10 are “pre-test” items.  You have 2 hours to take the CM exam.
  4. Schedule a routine study plan.  Successful exam takers for the COHN/COHN-S exams study an average of 9-10 hours weekly for 4-6 months before taking the exam. 
  5. Take care of yourself.  Maintain your normal schedule of exercise, rest, and proper nutrition especially in the few days before the exam.  Consider taking some personal time away from work for review and rest right before the exam.
  6. Plan the logistics of exam day.  Allow plenty of time to arrive at your destination.  Map it out and perhaps scout out the location ahead of time.  Consider having a backup plan like printed directions.
  7. On exam day.  Be sure to have your state issued identification with you.  Leave personal items at home or in your vehicle.  Review any instructions you received from the examination vendor.
  8. Time management during the exam.  You will have 3 hours to answer 160 questions for the core exams, so pace yourself.  You can mark questions if you wish to go back to them later.  Work at a steady pace without rushing.
  9. No tricks, honest!  Some people may overthink a question and look for traps.  Try not to overthink or make assumptions.  Read each question carefully and select the most appropriate or best response based on the question.
  10. Manage stress.  Take a deep breath periodically to relax.  Remember, you do not need 100% to pass.  If you can relax, the answers may come more readily.