RDN
CDR Registered Dietitian Nutritionist Exam (RDN)
The CDR RDN exam certifies registered dietitians in nutrition assessment, medical nutrition therapy, food science, and community nutrition.
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RDN Exam Overview
| Detail | Information |
|---|---|
| Full Name | CDR Registered Dietitian Nutritionist Exam (RDN) |
| Governing Body | CDR |
| Time Limit | 3 hours |
| Passing Score | 25 scaled (1-50 scale) |
| Exam Fee | $250 USD |
| Category | Allied Health & Medicine |
| C3RT App Available On | iPhone, iPad, and Mac |
| Official Source | CDR official website ↗ |
RDN Content Areas and Domains
| Domain / Content Area | Exam Weight |
|---|---|
| Principles of Dietetics | 12% |
| Nutrition Care for Individuals and Groups | 50% |
| Management of Food and Nutrition Programs and Services | 21% |
| Support of Research | 17% |
Domain weights are approximate and based on the CDR content outline. Always verify at the official source before your exam.
Topics Covered
- ✓ Domain I: Principles of Dietetics - 21%
- ✓ Domain II: Nutrition Care for Individuals and Groups - 45%
- ✓ Domain III: Management of Food and Nutrition Programs and Services - 21%
- ✓ Domain IV: Foodservice Systems - 13%
How C3RT Helps You Pass the RDN
Adaptive Practice
Questions adapt to your weak areas automatically so every study session on the RDN is time well spent.
Diagnostic Mocks
Full-length mock exams timed to the real RDN format with detailed score breakdowns by topic.
Mistake Bank
Every wrong answer is saved for targeted re-drill. The system resurfaces your mistakes until they stick.
Native on iOS & Mac
Built with SwiftUI, not a web wrapper. Instant load, offline support, hardware-speed rendering.
RDN Frequently Asked Questions
What does RDN stand for?
RDN stands for CDR Registered Dietitian Nutritionist Exam (RDN). It is administered by CDR.
Who administers the RDN?
The CDR Registered Dietitian Nutritionist Exam (RDN) is administered by CDR. For official information, visit the CDR website.
What is the passing score for the RDN?
The passing score for the RDN is 25 scaled (1-50 scale), as set by CDR. Scoring methodology and passing standards may be updated periodically. Always verify current requirements with the governing body.
How much does the RDN exam cost?
The RDN exam fee is $250 USD. This fee is set by CDR and may vary by testing centre, region, or membership status. Additional fees for registration or rescheduling may apply.
How is the RDN scored?
Scaled score of 25 on a 1-50 scale. CDR states the number of questions that must be answered correctly to reach a scaled score of 25 varies by exam because of CAT difficulty adjustment. Always confirm the current standard with CDR before testing.
What does the RDN cost?
$250 USD examination fee (paid by credit card at time of scheduling). Optional test bundle with a discounted second attempt: $350 total for RD. Fees are set by CDR and change periodically; confirm current pricing before you register.
What should I know about the current RDN exam blueprint?
questionCount left null because the exam is adaptive and variable-length (125-145); the split is given in scoredNote. Facts taken directly from CDR's current (2026) RD Exam Handbook for Candidates.
How difficult is the CDR RD exam and what is the pass rate?
The Commission on Dietetic Registration (CDR) Registered Dietitian Nutritionist (RDN) exam is considered moderately to significantly challenging. First-attempt pass rates have typically ranged from 70–80% for candidates completing supervised practice programs. The exam covers nutrition assessment, food science, management, education, and evidence-based practice.
What are the eligibility requirements for the CDR RD exam?
You must complete an accredited Didactic Program in Dietetics (DPD) and an accredited supervised practice program (dietetic internship or coordinated program). Beginning January 1, 2024, CDR requires a minimum of a master's degree for RD eligibility. This significant credential change means the profession now requires graduate-level education as the minimum entry standard.
How long should I study for the CDR RD exam?
Most candidates spend 2–4 months in focused exam preparation after completing their supervised practice program. The Inman's Complete Review for the RD Exam and CDR's official practice tests are widely used. Working systematically through all four major content areas with practice questions is the standard approach.
What career value does the CDR RD credential provide?
RDs work in clinical settings, community nutrition, foodservice management, public health, and private practice. The RD is required for Medicare/Medicaid medical nutrition therapy reimbursement. Registered Dietitians earn $60,000–$90,000+ with higher earnings in clinical specialties and private practice. The master's degree requirement is expected to increase professional recognition and earning potential over time.
What is the CDR RD exam retake policy?
Candidates who fail may retake the exam after a 45-day waiting period. CDR allows multiple retake attempts, but each requires full fee payment. After three failed attempts, CDR may require a review of additional education or supervised practice before further attempts.
How long is the CDR RD credential valid?
The CDR RD credential requires renewal every five years through CDR's Professional Development Portfolio (PDP) process. Annual maintenance fees must also be paid to maintain active registration status.
What continuing education is required for CDR RD renewal?
The CDR PDP process requires completing 75 continuing professional education units (CPEUs) over each five-year recertification period, with a structured learning needs self-assessment and individualized learning plan. CPEUs must be from CDR-approved providers and include a balance of self-study, live education, and professional activities.
Is the CDR RD the same as an RDN (Registered Dietitian Nutritionist)?
Yes. CDR updated the credential name to allow practitioners to use either "Registered Dietitian" (RD) or "Registered Dietitian Nutritionist" (RDN), both designations refer to the same credential awarded by CDR. The underlying certification, eligibility requirements, and renewal processes are identical regardless of which title you use.
C3RT is a native iOS and macOS exam preparation platform covering the CDR Registered Dietitian Nutritionist Exam (RDN), a Allied Health & Medicine certification, administered by CDR. C3RT is not affiliated with or endorsed by CDR. Certification names and trademarks are the property of their respective organisations. For official exam registration, eligibility requirements, and content outlines, visit the CDR official website ↗ .