The Certified Nephrology Nurse, or CNN, credential is offered by the Nephrology Nursing Certification Commission (NNCC). It is designed for registered nurses who practice in multiple areas of nephrology nursing and provide care for patients with kidney disease, kidney replacement therapies, and transplant-related needs.
The CNN exam measures the knowledge needed to provide safe, effective nephrology nursing care across several practice areas. Candidates should review the current NNCC requirements before applying, especially because NNCC has announced 2026 updates to the CNN program and exam blueprint.
CNN Exam Overview
| Credentialing organization | Nephrology Nursing Certification Commission (NNCC) |
| Credential | Certified Nephrology Nurse (CNN) |
| Exam format | Computer-based multiple-choice exam |
| Number of questions | 150 questions |
| Time limit | 3 hours |
| Passing score | A standard score of 95, which NNCC states is achieved by answering 70% of the questions correctly |
Online CNN Prep Course
If you want to be fully prepared, Mometrix offers an online CNN Prep Course. The course includes review lessons, practice questions, flashcards, progress tracking, and study tools designed to help you review the major areas tested on the exam.
- 50+ CNN lessons
- 640 CNN practice questions
- 490+ digital flashcards
- Progress tracking
- Bonus study tools and test-taking tips
Who Is Eligible for the CNN Exam?
To qualify for the CNN exam, candidates must meet NNCC eligibility requirements. In general, candidates need:
- A full and unrestricted registered nurse license in the United States or its territories
- At least 2,500 hours of experience in nephrology nursing within the two years before applying
- Experience in one or more approved nephrology nursing areas
- 30 contact hours of approved continuing education in nephrology nursing within the two years before applying
Approved experience areas may include home hemodialysis, home peritoneal dialysis, inpatient acute kidney injury on kidney replacement therapy, inpatient critical care on kidney replacement therapy, CKD management not on kidney replacement therapy, and kidney transplant.
Candidates should confirm the current eligibility rules with NNCC before applying, especially if their nursing experience, license status, or continuing education history has special circumstances.
What Is Covered on the CNN Exam?
NNCC has posted revised CNN test specifications effective September 1, 2026. Candidates testing near the transition should confirm which exam outline applies to their test date.
| Content Area | Percent of Exam | Main Focus |
|---|---|---|
| Concepts of Kidney Disease Across the Life Span | 30% | Kidney disease concepts, disease progression, pathologic processes, complications, and care considerations across the life span |
| Acute In-patient Therapies | 25% | Acute kidney injury, kidney replacement therapy, critical care therapies, apheresis, CRRT, and related inpatient treatment issues |
| Peritoneal Dialysis | 20% | Peritoneal dialysis therapy, complications, patient education, monitoring, and ongoing management |
| Home Hemodialysis | 15% | Home hemodialysis therapy, patient teaching, treatment support, safety, access care, and complication management |
| Transplant | 10% | Kidney transplant care, pre-transplant considerations, post-transplant care, complications, and long-term follow-up |
CNN Exam Objectives
The CNN exam also tests several objectives across the content areas. These objectives describe the types of knowledge and judgment candidates are expected to apply.
| Objective | Percent of Exam |
|---|---|
| Recognize pathologic processes and complications of kidney disease | 20% |
| Select appropriate interventions for pathologic processes and complications | 21% |
| Apply physiologic and technical principles of kidney replacement therapies | 11% |
| Select teaching and learning strategies for patients, families, health professionals, and the public | 15% |
| Select appropriate medication administration actions for patients with kidney disease | 12% |
| Apply principles of infection control | 8% |
| Promote positive patient outcomes through interdisciplinary collaboration, cultural and psychological considerations, staff development, and quality improvement | 13% |
How Do I Register for the CNN Exam?
Candidates apply through NNCC. In the process of applying, candidates provide all the information regarding eligibility, required documentation, and payment for the test. After the application has been processed, the applicants will be provided with further instructions regarding testing arrangements. It is important for the candidates to review the instructions from the NNCC prior to submitting the application.
What Should I Bring on Test Day?
Before test day, review your exam permit and appointment instructions carefully. Requirements may vary by testing site, but candidates should generally be prepared to bring:
- A government-issued photo ID
- Proof of nursing license, if required by the testing instructions
- Your examination permit or authorization information
- A sweater or jacket in case the testing room is cool
Your name on your ID should match the name used during registration. If your identification does not meet the testing requirements, you may not be allowed to test.
What Should I Not Bring?
Ensure you do not have any prohibited personal belongings in the exam room. This normally includes phones, other electronic gadgets, bags, handbags, notes, study aids, or anything else prohibited.
Comply with all directions from test center personnel. Breaking testing rules may lead to removal from the test or cancellation of scores.
How Is the CNN Exam Scored?
NNCC states that candidates must receive a standard score of 95 to pass the CNN exam, which is achieved by answering 70% of the test questions correctly.
Test scores are usually made available after completion of the test. Candidates who fail need to go through the score information and emphasize their study on weak areas before retesting.
Can I Retake the CNN Exam?
Candidates who fail the examination may be allowed to take the CNN examination again in accordance with the NNCC requirements. Retesting fees, deadlines, and eligibility criteria may vary, and thus candidates are recommended to consult the updated NNCC guide before retesting.
How Can I Prepare for the CNN Exam?
Start by reviewing the current CNN test blueprint and test specifications. The blueprint shows the major content areas and how much weight each area receives on the exam.
Next, prioritize the biggest content areas in your studies: the concepts of kidney disease, acute in-patient therapies, and peritoneal dialysis. These are the main components of the test and hence poor performance in these areas will result in low scores.
Practice questions are useful because they help you apply nephrology nursing knowledge in the way it may appear on the exam. After each practice session, review missed questions carefully so you understand the clinical concept, intervention, therapy principle, medication issue, or infection control rule behind the correct answer.
