NBPHE is approved to offer the CDI exam through the U.S. Department of Veterans Affairs. Veterans, their eligible dependents, and reservists may qualify for reimbursement of the exam costs through veteran’s education benefits. For more information, visit the U.S. Department of Veterans Affairs Education Benefits website.

Refer to the CDI Candidate Handbook for detailed information about the scheduling and examination process.

Yes! Practice exams, review materials, and the CDI Study Guide are available. See CDI Study Resources.

Preparation time varies depending on your background and experience. On average, candidates spend between 1 and 6 months studying, devoting a few hours each week. If you’re newer to the field, you may want to give yourself more time to review key concepts. If you have several years of experience, you may need less time, but you should still plan for focused review sessions to refresh your knowledge and skills with the exam format.

Feeling nervous is completely normal. A structured and consistent study plan can help reduce anxiety by building familiarity with the content and exam format. The CDI Study Resources page includes tools to help you create and follow that plan, such as the digital CDI Planner, practice tests, flash cards, and the CDI study guide. These resources are designed and reviewed by subject matter experts to align directly with the CDI exam.

Practice questions are especially helpful for reducing uncertainty about what to expect. Be sure to take regular breaks during study sessions to avoid burnout, and use stress-management techniques such as deep breathing, stretching, or short walks. On exam day, aim for a good night’s sleep, eat a balanced meal, and arrive early to your exam session so you feel calm and prepared.

Yes. While professional experience provides a strong foundation, the exam is designed to assess knowledge and skills across the full scope of disease intervention practice. Studying ensures you refresh less familiar topics, understand how material is presented in a testing environment, and build confidence with the exam format. Even seasoned professionals benefit from a structured review to perform at their best on test day.

Candidates who do not pass the CDI exam will be limited to two (2) retakes in a twelve (12) month period. You may reapply via CertCentral the day after your exam or if you were absent on your scheduled date. The retake fee is $150. After payment, you will receive an email from Meazure Learning with scheduling instructions.

All Certified in Disease Intervention certificants in good standing are listed on the NBPHE Certificant Directory, but exact scores are not specified.

The CDI exam results uses a scaled scoring. Candidates can score between 200 and 800. A score of 500 is needed to pass the exam.

A scaled score is a representation of a candidate’s total number of right answers (raw score) transformed to a uniform and standardized scale. Scaled scoring is a certification industry best practice for reporting high stakes exam scores. It provides a consistent scale of measurement from one exam session to the next; the same scaled score signifies the same degree of knowledge. This means that scores from different versions of the exam indicate the same level of performance regardless of which exam form a candidate has received. This will consider the potential difference in difficulty between exam forms.

Meazure Learning testing centers are the best option for taking the exam! Testing centers are located throughout the US and in over 100 other countries. Exams can be scheduled Monday-Friday and on some weekends.

Search for testing centers

Testing Center In-Person Support Monday to Friday 8 am to 7 pm ET 

• Email: [email protected] 
• Phone: 1-888-900-0005, Option 1 

If a testing center is not near your area, testing via live online proctoring (LOP) is available. LOP testing is available 24/7 year-round. During your LOP exam session, the proctor will log in remotely to your computer.

Watch the Video Overview of Live Online Proctoring

Second Camera Requirement: LOP candidates must have a mobile device or portable tablet equipped with a front-facing camera and stable internet connectivity during the exam session. Candidates must also have a charger within reach of their workspace, as mobile device’s camera usage will drain its battery. Review the Second Camera Requirements and Watch the Video Tutorial prior to your test date.

For Exam Day Live Online Proctoring (LOP) 24/7 Support: 

• Real-Time Chat: https://support.meazurelearning.com/hc/p/chat
• Ticket support (for non-urgent matters): https://support.meazurelearning.com/hc/requests/new?ticket_form_id=38032314304781  
• Phone: 1-855-772-8678, Option 1

Review the LOP Fact Sheet at least 24 hours before your exam for technical requirements and additional details. Confirm the following before your exam:

• Private room with a clean desk surface, free of people, paper, and disruptions.
• Use a computer with admin access
• Download the Guardian for your browser in advance

Unlike degrees and certificate programs, certifications must be maintained over time. Maintenance of the CDI credential ensures that certificants are staying current on emerging trends and best practices in the field and continuing to meet a professional standard. Recertification also contributes to ongoing professional development through lifelong learning.

The recertification period for the CDI is 3 years. Review the CDI Recertification Requirements webpage and follow the CDI Recertification Instructions which shows you how to report credits, view your reported credit history, update your contact information, and apply for recertification.

CDI certificants must earn a total of 30 recertification credits during the 3-year recertification period.

There is a fee of $95 due when you submit your recertification application.

Public health and disease intervention activities such as conferences, publications, presentations, courses, webinars, workshops, and volunteer activities can count towards recertification. The Recertification Activity Credit Guide has a full list of activities that count towards recertification.

Unlike other professional licenses or credentials, CDI certificants do not have to attend certain paid trainings or events to recertify. The recertification credits you earn can be from any organization/provider. NBPHE does not have a list of authorized providers for recertification activities. NBPHE accepts any public health or disease intervention related activity for recertification as long as it fits in the categories listed in the Recertification Activity Credit Guide. In fact, many CDIs earn credits by participating in webinars, conferences, meetings, and events through their job.

Each hour (60 minutes) spent participating in a recertification activity equals one recertification credit.

If the amount time you spend participating in a recertification activity does not equal a whole number, you can round up to the nearest whole number. For example, a disease intervention related webinar that lasts 1.5 hours can count for 2 credits.

Yes! Your volunteer service such as participating in a community outreach event, joining a public health awareness event, or being a member of a board or committee (e.g., item writer/ reviewer, study guide, passing score study, exam review, job task analysis) will count towards recertification.

It is recommended that each time you participate in a recertification activity you immediately log into CertCentral to report the activity. Follow the CDI Recertification Instructions which shows you how to report credits. Reporting your recertification activities in real-time will help you track how many credits you have earned and help you avoid trying to remember all of your eligible activities at once when your recertification comes due. 

NBPHE hosts several fun recertification events like Webinar Wednesdays and NBPHE Book Club. Databases like the RECERT Activity Finder, CDC TRAIN, Public Health Learning Navigator, Public Health Training Center Network, and UniversiDI are also great places to start, offering thousands of courses (many are free) that count as credits. 

Qualifying activities for recertification credits include continuing education, professional development opportunities, and research activities that interest you. Join our private CDI Professionals Group on LinkedIn for peer discussions, join our NBPHE Book Club to discuss public health books, or attend our Webinar Wednesday series. Design a certification and learning process that enriches your path.

Please note that day-to-day work experience/work roles do not count towards recertification.

If you are not sure whether an activity will count towards recertification, you can email a brief description of the activity to NBPHE staff at [email protected] to request guidance.

Don’t worry, we know how busy life gets! As long as your CDI is active and current, you can extend your CDI recertification cycle by 3 or 6 months. Log into CertCentral to submit a request and you will automatically be granted an extension. To submit a request go to the “Applications” tab and click “My Applications.” Click “Apply Now” and select “Recertification Extension Request Application” from the drop-down menu.

Yes! Lapsed certificants with an expired certification can regain active status.

If your certification has been expired for less than 5 years, you reinstate your CDI by reporting reporting credits for all missed 3-year cycles, submitting the CDI Reinstatement Application, and paying the $95 fee. Follow the CDI Reinstatement Instructions.

If your certification has been expired for 5 years or more, you must retake the CDI exam. Contact us at [email protected] to request to be re-registered to retake the exam.