Certification Portal 
Certified in Disease Intervention (CDI)
What is CDI Certification?
CDI Certification assesses the competence of disease intervention (DI) professionals, offering evidence of essential knowledge and a standardized benchmark for skills. Certification requires continuous professional development for maintenance.
Disease intervention professionals are on the front lines of public health, working to prevent the spread of infectious diseases through comprehensive disease investigation activities such as case investigation, contact tracing, and partner services. They provide the client-centered testing, treatment, and prevention services that support people diagnosed with or exposed to infectious diseases and their communities.
Value of CDI Certification
Earning the CDI certification validates your knowledge, skills, and abilities as a certified DI professional. The CDI certification demonstrates excellence in the core competencies of disease intervention practice. In addition, CDI certification allows employers and other interest groups to identify individuals with the competencies needed to deliver high-quality, impactful disease intervention services.
CDI Exam Content
The Certified in Disease Intervention (CDI) exam covers the areas of knowledge relevant to disease intervention practice. The examination is developed to assess a person’s knowledge of these competencies, regardless of their area of expertise.
Explore the content of the CDI Exam Content Outline page.
Exam Format
The CDI certification exam is a computer-based three-hour exam that consists of 120 multiple-choice, single-best-answer questions. The CDI exam is offered all year round at Computer-Based Testing Centers and via Live-Online Proctor.
Exam Retake
Candidates who do not pass the exam with their initial attempt may retake the CDI exam twice per 12-month period.
How to Get Involved
Advancing the disease intervention (DI) workforce and their professional skill set requires a commitment from DI professionals.
We are often seeking DI professionals to serve on volunteer committees, and when positions are open they will be posted here.
These are excellent opportunities to share your knowledge and skills and to network with colleagues in your field.
The Certified in Disease Intervention Certification Program was supported through funding from the Centers for Disease Control and Prevention (CDC) through a Cooperative Agreement awarded to the Association of Schools and Programs of Public Health (ASPPH) and sub-awarded to the National Board of Public Health Examiners (NBPHE).
Thanks to our CDI volunteers, funders, and strategic partners in supporting the development of the Certified in Disease Intervention (CDI) Certification Program.
What Do Disease Intervention Professionals Do?
Disease intervention professionals are essential members of the national public health workforce and reduce the spread of infectious diseases in communities through contact tracing, partner services, health education, and facilitating access to health care and other supportive services.
Disease intervention professionals conduct infectious disease intervention activities including:
- Performing case investigation interviews with people diagnosed with reportable infectious diseases for the purposes of identifying risk factors, eliciting contacts, and referring for appropriate services.
- Collecting enhanced surveillance data through case investigations.
- Contact tracing to identify, locate, notify, and refer people exposed to an infectious disease.
- Conducting field investigations to locate people diagnosed with or exposed to an infectious disease for interview or notification.
- Providing field-based testing and treatment services for reportable infectious diseases.
- Conducting community outreach to provide infectious disease testing and treatment services in community settings.
- Collaborating with medical providers for the management confirmed or suspected cases of infectious disease.
- Conducting emergency preparedness activities for infectious disease prevention and control.
Who is a Disease Intervention Professional?
Disease intervention roles that most closely align with the knowledge and skills assessed on the CDI exam include, but are not limited to:
- Communicable/Infectious Disease Epidemiologist who conducts disease investigations
- Community Health Worker who supports identification and management of infectious diseases
- Disease Intervention Specialist (DIS)
- Harm reduction or syringe services program staff
- HIV/STI Prevention and Testing professionals
- Linkage to Care Coordinator for HIV/HCV or other infectious diseases
- PrEP/PEP Navigator
- Public Health Nurse who does conducts disease investigations
- Ryan White Case Manager
- Surveillance Coordinator
- TB Outreach/DOT professional
