The Registration Examination for Dietitians, run by the Commission on Dietetic Registration (CDR), is a variable-length computer adaptive test of 125 to 145 multiple-choice questions taken in a three-hour window, scored on a 1–50 scale with a minimum passing score of 25. For a 2026 sitting you study the 2022–2026 outline, where Nutrition Care for Individuals and Groups carries 45% of the exam; candidates testing January 1, 2027 or later switch to the restructured 2027–2031 specifications. Build your plan around those weights, use CDR's own study outline and practice items, and verify ID, scheduling, and retake rules against the current Candidate Handbook before test day.
What this exam is and which version applies to you
The Commission on Dietetic Registration (CDR), the credentialing agency of the Academy of Nutrition and Dietetics, administers the Registration Examination for Dietitians. Passing it earns the registered dietitian credential, which CDR materials style as both RD and RDN.
The exam is computer-based and administered year-round by appointment at more than 250 Pearson VUE professional test centers in the United States and selected international locations. All questions are practice related and presented in multiple-choice format with four answer options.
Version matters. The current content outline took effect January 1, 2022 and applies through December 31, 2026, based on a 2020 practice analysis. CDR has approved a replacement: the January 1, 2027 – December 31, 2031 test specifications were approved on June 25, 2025 and restructure the domains significantly. If you test in 2026, prepare from the 2022–2026 outline; if you test in 2027 or later, switch to the new specifications before you plan a single study session.
Official sources: CDR Registration Examination for Dietitians Study Outline, 2022–2026 — Effective January 1, 2022; approved September 26, 2020; CDR Registration Examination for Dietitians Candidate Handbook, 2026 — Exam procedures, exam content, results, reauthorization, and FAQ sections; CDR Registered Dietitian Examination Test Specifications and Study Outline, January 1, 2027 – December 31, 2031 — Approved by CDR June 25, 2025; domain listing, page 1
Eligibility and authorization to test
You do not book this exam directly. CDR first verifies that you meet the academic and supervised practice criteria for eligibility through its Registration Eligibility Processing System (REPS); once approved, Pearson sends you an Authorization to Test email, normally within 48 hours.
That authorization is valid for one year, and it expires if you take the exam, let the year lapse, miss a cancellation deadline, arrive late, fail to present qualifying ID, or decline the non-disclosure agreement. CDR states the path from eligibility submission to the authorization email takes less than a week.
The retrieved documents confirm that eligibility rests on academic and supervised practice criteria but do not spell out the current degree or practice-hour requirements. Check those details directly with CDR before assuming you qualify, since the criteria sit outside the handbook excerpts reviewed here.
Official sources: CDR Registration Examination for Dietitians Candidate Handbook, 2026 — Exam procedures, exam content, results, reauthorization, and FAQ sections
How the computer adaptive format works
The exam uses computer adaptive testing (CAT): the program selects each next question based on your performance, so no two candidates see the same paper. Length and difficulty adjust to home in on your ability against the passing standard.
Every candidate receives at least 125 questions — 100 scored plus 25 unscored pretest items — and can receive up to 145, with 120 scored and 25 pretest. Pretest questions look identical to scored ones and cannot be distinguished, so you should answer everything as if it counts.
Your testing appointment runs three and a half hours: a 20-minute tutorial, three hours of exam time starting when question one appears, and a 10-minute post-exam survey. You may hide the on-screen clock. Answering fewer than 125 questions when time runs out shuts the exam down and scores it as a failure, so pace matters as much as accuracy.
Two format rules shape how you practice. First, each question must be answered before the next appears, and you cannot return to review or change earlier responses — there is no end-of-exam sweep. Second, an on-screen calculator is built into the exam and a simple handheld one is available on request; you may not bring your own.
Official sources: CDR Registration Examination for Dietitians Candidate Handbook, 2026 — Exam procedures, exam content, results, reauthorization, and FAQ sections
Content domains and weights for 2026
The 2022–2026 specifications divide the exam into four domains, with clinical nutrition care carrying nearly half the weight. Questions from all domains appear intermingled, never grouped in content order.
Every question targets the entry level and is written at either the comprehension level — accurately understanding concepts, including translating information in graphs, tables, and formulas — or the application level, which asks you to use knowledge to solve a problem or choose a course of action.
For 2027 candidates, the structure changes. The new specifications rename and rebalance the domains: Fundamentals of Dietetics Practice (23%), Community and Public Health Nutrition (22%), Human Nutrition and Medical Nutrition Therapy (40%), and Food Science and Food Systems (15%). Community nutrition becomes its own domain, and the clinical domain's share rises. Do not study from the wrong table.
| Domain (2022–2026 outline) | Weight |
|---|---|
| I. Principles of Dietetics — food and nutrition sciences, education and communication, research applications | 21% |
| II. Nutrition Care for Individuals and Groups — screening and assessment, diagnosis, planning and intervention, monitoring and evaluation | 45% |
| III. Management of Food and Nutrition Programs and Services — management functions, human resources, finance, marketing, quality management | 21% |
| IV. Foodservice Systems — menu development, procurement through service, sanitation and safety, equipment and facility planning | 13% |
Official sources: CDR Registration Examination for Dietitians Study Outline, 2022–2026 — Effective January 1, 2022; approved September 26, 2020; CDR Registration Examination for Dietitians Candidate Handbook, 2026 — Exam procedures, exam content, results, reauthorization, and FAQ sections; CDR Registered Dietitian Examination Test Specifications and Study Outline, January 1, 2027 – December 31, 2031 — Approved by CDR June 25, 2025; domain listing, page 1
How scoring works
The exam is scored on a scale of 1 to 50, and the minimum scaled score required to pass is 25. There is no fixed number of correct answers: the adaptive algorithm equalizes slightly easier and harder exams so candidates are neither rewarded nor penalized for the form they drew.
Your printed score report appears as you leave the test center and shows your total scaled score plus content-area sub-scores. Treat sub-scores cautiously: CDR notes they only give a general indication of performance, and areas with fewer items affect the total less and are measured less precisely. Sub-scores do not drive the pass-fail decision.
If you pass, information about maintaining the credential arrives by email within a week. If you stop before answering the minimum 125 questions, the exam is not scored at all — you receive documentation of the decision, no refund, and must reauthorize with CDR to try again.
CDR does not release exam questions or correct answers to anyone, which is worth remembering when evaluating third-party question banks claiming inside knowledge.
Official sources: CDR Registration Examination for Dietitians Candidate Handbook, 2026 — Exam procedures, exam content, results, reauthorization, and FAQ sections
Building a weight-aware study plan
An editorial recommendation, not an official rule: let the domain percentages drive your calendar. Start with Domain II's 45% — screening and assessment, diagnosis, planning and intervention, monitoring and evaluation — then split remaining time across Domains I and III, and close with Foodservice Systems.
Within each domain, work from the official study outline rather than a generic topic list. Domain I spans food and nutrition sciences, education and communication, and research applications. Domain III runs from management functions and human resources through finance, marketing, and quality management. Domain IV covers menu development, procurement, production and service, sanitation and safety, and facility planning. CDR publishes the full expanded outline, so use it as your coverage checklist instead of guessing.
For practice, CDR offers a comprehensive study outline, suggested study references, a study-methods infographic, and practice exam questions with answers and rationales at cdrnet.org/study. CDR does not endorse any commercial preparation program and states that purchasing one is not required and that no purchase guarantees a pass. Because the exam tests application as well as comprehension, favor practice items that force a decision — pick the assessment finding, the next step, or the indicator to monitor — over pure recall drills.
Since you cannot revisit questions, practice deciding and moving on. Timed sets where you commit to each answer before advancing build the habit the test-center software enforces.
- Weight your hours roughly in proportion to domain percentages, adjusting for your own weak areas after a first practice set.
- Map every practice question back to an outline topic so gaps surface against the official checklist, not memory.
- Use CDR's practice questions with rationales as your calibration source before buying anything else.
Official sources: CDR Registration Examination for Dietitians Study Outline, 2022–2026 — Effective January 1, 2022; approved September 26, 2020; CDR Registration Examination for Dietitians Candidate Handbook, 2026 — Exam procedures, exam content, results, reauthorization, and FAQ sections
Practice the calculations the outline names
The outline lists anthropometric data, comparative standards, and energy and nutrient requirements among assessment topics, and formulas and calculations under nutrition support — so arithmetic fluency is a fair preparation target even though specific clinical interpretation rules come from the suggested study references, not from the outline itself.
The drill below is deliberately self-contained: it is pure arithmetic with every premise stated, so you can check your own work without any clinical judgment. Interpretation thresholds — what a given percent change means for a diagnosis — should be learned from CDR's suggested study references.
Practice drill
Assume a patient's usual body weight is 64 kg and current weight is 58 kg, with no other data given. Calculate the percent weight change from usual body weight, rounded to one decimal place.
Show answer
A loss of about 9.4%: (64 − 58) ÷ 64 × 100 = 9.375, which rounds to 9.4%.
First find the change: 64 − 58 = 6 kg. Percent change is measured against the starting value, so divide by the usual body weight, not the current one: 6 ÷ 64 = 0.09375. Multiply by 100 to get 9.375%, or 9.4% to one decimal. The classic slip is dividing by the current weight, which yields 10.3% and overstates the change. The only assumption here is that 64 kg is the reference value; what threshold of weight change is clinically meaningful is an interpretation question the arithmetic cannot answer.
Official sources: CDR Registration Examination for Dietitians Study Outline, 2022–2026 — Effective January 1, 2022; approved September 26, 2020; CDR Registration Examination for Dietitians Candidate Handbook, 2026 — Exam procedures, exam content, results, reauthorization, and FAQ sections
Fees, scheduling, and retakes
The dietitian exam fee is $250, paid by credit card when you register for an appointment, and it is separate from Academy membership dues and CDR registration maintenance fees. Appointments must be made at least 48 hours in advance.
The same 48-hour rule governs changes: cancel or reschedule online at least 48 hours before your appointment for a refund, and note that your new appointment must fall within your authorization period. No refund is given if you fail or skip the appointment, and you cannot schedule by calling a test center directly.
CDR sells an optional bundle: for $350 total you get your initial attempt plus a $100 discount retake voucher, bought as an upgrade at checkout. Vouchers are non-transferable and non-refundable and must match the exam taken.
If you are unsuccessful, you must reauthorize with CDR and pay the current fee again; retesting is allowed 46 days after the failed attempt. There is no limit on attempts as long as you wait between dates. Candidates whose employment requires passing sooner may request a one-time 45-day waiver with an employer letter on company letterhead, processed in 48 to 72 hours. State licensure candidates should also confirm any state-specific retesting rules with their licensure board.
Official sources: CDR Registration Examination for Dietitians Candidate Handbook, 2026 — Exam procedures, exam content, results, reauthorization, and FAQ sections
Test-day verification checklist
Most avoidable failures are administrative, not academic: wrong ID, late arrival, or unanswered questions. Verify each item below against the current handbook in the week before your appointment.
These conditions come from the 2026 Candidate Handbook; confirm nothing has changed for your sitting before relying on the list.
- Bring one original, unexpired government-issued ID showing your name, photograph, and signature; the name must match your Pearson profile, and workplace or university ID is not accepted.
- Book at least 48 hours ahead and confirm you received the scheduling confirmation email — without it, no exam is booked.
- Arrive on time; late candidates are not seated and forfeit the fee.
- Plan to answer all questions, since fewer than 125 responses scores as a failure, and remember you cannot return to change any answer.
- Leave personal electronics, bags, notes, and your own calculator out of the testing room; store devices powered off in the designated area.
- Expect security screening, including possible palm-vein scanning, and an erasable note board usable only after the exam starts.
- Collect your printed score report before leaving, and save the CDR candidate ID from it — you need it for reauthorization.
Official sources: CDR Registration Examination for Dietitians Candidate Handbook, 2026 — Exam procedures, exam content, results, reauthorization, and FAQ sections
Official sources
Facts checked against CDR's 2026 Candidate Handbook and official study outlines: