This overview includes information to help you prepare for the Certified Nephrology Nurse exam. You will find details about eligibility, exam content, fees, registration, scoring, retakes, recertification, and study resources.
Questions150 multiple-choice questions | Time Limit3 hours |
Passing ScoreStandard score of 95 | Certification Period3 years |
Exam Background and Purpose
The Certified Nephrology Nurse, or CNN, credential is offered by the Nephrology Nursing Certification Commission. It is designed for registered nurses who practice in multiple areas of nephrology and care for patients with kidney disease across the lifespan.
CNN certification recognizes advanced knowledge in chronic kidney disease, kidney replacement therapies, transplantation, acute inpatient therapies, medications, infection prevention, patient education, and interdisciplinary care.
Key point: The CNN credential is intended for registered nurses who work across multiple nephrology settings. The Certified Dialysis Nurse credential is more narrowly focused on nurses who care for patients receiving in-center hemodialysis.
CNN Eligibility Requirements
Applicants must satisfy the nursing-license, professional-experience, and continuing-education requirements before applying for the CNN exam.
Minimum Requirements
- Hold a current, full, and unrestricted registered nurse license in the United States or one of its territories.
- Complete at least 2,500 hours of qualifying nephrology nursing experience during the two years before applying.
- Complete 30 contact hours of approved nephrology nursing continuing education during the two years before applying.
Qualifying Nephrology Experience
The required experience may be earned in one or more of the following areas:
- Home hemodialysis
- Home peritoneal dialysis
- Inpatient acute kidney injury requiring kidney replacement therapy
- Inpatient critical care involving kidney replacement therapy
- Chronic kidney disease management before kidney replacement therapy
- Kidney transplantation
NNCC may audit an application and request documentation of the applicant’s nursing license, experience, and continuing education.
CNN Test Overview
The CNN exam contains 150 multiple-choice questions and must be completed within three hours. Approximately 25 questions may be unscored experimental questions used to evaluate material for future examinations.
Experimental questions are not identified. Treat every question as though it contributes to your final result.
The CNN content blueprint changes on September 1, 2026. Use the blueprint that applies to the date of your scheduled examination.
Skills Measured on the Exam
Questions may require candidates to:
- Recognize kidney-disease processes and complications
- Select appropriate nursing interventions
- Apply physiologic and technical principles of kidney replacement therapies
- Choose appropriate patient and caregiver teaching strategies
- Administer and monitor medications safely
- Apply infection-prevention principles
- Collaborate with the interdisciplinary health care team
- Support quality improvement and positive patient outcomes
Costs and Payment Options
The standard examination fee is $350. Members of an eligible NNCC partner organization may qualify for a reduced fee.
CNN Fee Basics
- Standard examination fee: $350
- Partner-member examination fee: $300
- Standard one-time retake fee: $200
- Partner-member one-time retake fee: $175
- Computer-based testing 90-day extension fee: $125
The examination fee includes a nonrefundable application-processing fee. Candidates should verify the current amounts before submitting payment.
Registration, Times, and Locations
Candidates apply through NNCC and submit the required eligibility information, documentation, and payment. Computer-based testing is offered throughout the year.
After an application is approved, the candidate receives an examination permit by email. The permit includes the information needed to schedule a testing appointment.
The examination permit is generally valid for a 90-day testing window. Candidates who do not test within that window may need to request an extension or submit a new application.
Prohibited Items
Reference books, notes, study materials, phones, communication devices, and other unauthorized personal items may not be used during the examination. The exam does not include calculations that require a personal calculator.
How Is the CNN Exam Scored?
Candidates must earn a standard score of 95 to pass. NNCC states that this corresponds to answering approximately 70% of the examination questions correctly.
The passing standard is established using the difficulty of the examination questions and the level of knowledge expected of a competent nephrology nurse. Candidates are measured against the established standard rather than against one another.
A score report is provided after the examination. Candidates who do not pass receive performance information for the major blueprint areas, which can be used to guide additional study.
Retaking the CNN Exam
An unsuccessful candidate has one opportunity to retake the examination at a reduced fee within one year of the original attempt.
Candidates who need to retest should review their score report, concentrate on the weakest blueprint areas, and verify the current retesting instructions before scheduling another appointment.
There is no penalty for guessing. Answer every question, even when you are uncertain about the best response.
Certification and Recertification
CNN certification is valid for three years. Certificants may recertify through continuing education or by passing the certification examination again before the credential expires.
Continuing-Education Option
To recertify through continuing education, a CNN must generally:
- Maintain a current, full, and unrestricted registered nurse license
- Complete at least 1,500 hours of nephrology nursing experience during the three-year certification period
- Complete 45 approved nursing continuing-education contact hours
- Complete at least 15 of the 45 contact hours in nephrology-specific education
- Submit the recertification application and fee before the credential expires
How Can I Prepare for the CNN Exam?
Start with the blueprint that applies to your scheduled test date. The change taking effect September 1, 2026 substantially increases the emphasis on acute inpatient therapies, home hemodialysis, and transplantation.
Most questions require application of nephrology nursing knowledge rather than simple recall. Practice recognizing complications, prioritizing interventions, interpreting patient findings, managing therapies, and educating patients and caregivers.
CNN Study Checklist
- Confirm which blueprint applies to your examination date.
- Review kidney anatomy, physiology, chronic kidney disease, and acute kidney injury.
- Study fluid, electrolyte, acid-base, cardiovascular, hematologic, and mineral-bone complications.
- Review peritoneal dialysis and home hemodialysis principles and complications.
- Study acute inpatient therapies, including continuous kidney replacement therapies and apheresis.
- Review kidney transplantation, immunosuppressive medications, rejection, and infection risks.
- Practice patient education, medication safety, infection prevention, and interdisciplinary collaboration.
- Complete practice questions under a realistic three-hour time limit.
- Review the reasoning behind every missed question.
CNN Study Resources
Top Study Guide:
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CNN® and Certified Nephrology Nurse® are registered certification marks of the Nephrology Nursing Certification Commission. NNCC is not involved with or affiliated with Mometrix Media LLC or StudyGuideZone.com, nor does NNCC endorse or sponsor any products or services offered by Mometrix Media LLC or StudyGuideZone.com.
