The Registered Dietitian Nutritionist exam is the credentialing test from the Commission on Dietetic Registration (CDR). You take it after you finish a graduate degree and meet CDR's academic and supervised-practice requirements. This page gives you the checked exam facts, free practice sets grouped by topic, worked explanations for sample questions, and a study plan to use alongside CDR's own handbook.
The Registered Dietitian Nutritionist has 145 questions, takes about 3 hours and costs $250[1] (Commission on Dietetic Registration (CDR), the credentialing agency of the Academy of Nutrition and Dietetics, verified Oct 26, 2026).
Numbers in brackets link to the official sources listed under Sources & last verified. Dates that have passed are removed automatically.
According to Commission on Dietetic Registration (CDR), the credentialing agency of the Academy of Nutrition and Dietetics, “The maximumnumber of questions possible is one hundred and forty-five (145); one hundred and twenty (120) scored questions and twenty-five (25) unscored pretest questions.”[1]
The Commission on Dietetic Registration (CDR) is the credentialing agency of the Academy of Nutrition and Dietetics. It uses the RDN exam to decide who can hold the registered dietitian credential. The exam is taken on a computer at Pearson VUE test centers. It is offered year-round, by appointment only.
You will see between 125 and 145 questions. Between 100 and 120 of them are scored. Another 25 are unscored pretest questions mixed in with the rest, and you can't tell which ones they are, so answer every question as if it counts. You have 3 hours once the timer starts, inside a 3.5-hour appointment. Results use a scaled score from 1 to 50, and you need 25 to pass. Your score appears on screen when you finish, and the test administrator gives you a printed score report.
The fee is $250 per attempt, paid by credit card when you book your appointment. Since January 1, 2024, the minimum degree for eligibility has been a graduate degree. You must also meet CDR's academic and supervised-practice criteria, which are checked in REPS. Once you are approved, you can test for 1 year at a time.
After you pass, you keep the credential through recertification: 75 CPEUs in each 5-year cycle, including 1 CPEU in ethics or health equity. This page does not cover retake waiting rules or state licensure. Licensure varies by state, so check the RD handbook at cdrnet.org and your state licensing board.
Prepare for the Registered Dietitian Nutritionist exam with our free practice test modules. Each quiz covers key topics to help you pass on your first try.
These are practice questions written for this site, not questions from the real exam. Each explanation shows why the right answer is right and why the others are wrong.
Question: A dietitian discovers that a specific brand of infant formula has been mixed at the wrong concentration for two days in a neonatal ICU. This event should FIRST be reported as:
Answer: A. A sentinel event requiring immediate root cause analysis
Explanation:
A is correct. The formula was mixed at the wrong strength in a neonatal ICU, and it reached very vulnerable patients over a long stretch of time. That makes it a sentinel event. It must be reported right away, followed by a root cause analysis of the whole process: the recipe, how the formula was prepared and how it was checked. B is wrong because logging it as a routine variance understates an error that reached infants. C is wrong because a corrective action plan comes after the analysis, and focusing on one person before reviewing the system can miss the real cause. D is wrong because a near-miss is an error caught before it reaches the patient, and this one reached patients. Rule to remember: when an error reaches a high-risk patient and could cause serious harm, escalate it at once and study the system before assigning fixes.
Question: A hospital dietitian is reviewing adverse events and finds a pattern of hypoglycemia in patients receiving parenteral nutrition. Using Six Sigma terminology, what is this pattern called?
Answer: A. A defect
Explanation:
A is correct. In Six Sigma, a defect is any output that fails to meet the customer's or patient's requirements. Patients on parenteral nutrition should have safe blood glucose, so each case of hypoglycemia is a defect. B is wrong because a specification is the requirement itself, such as a target glucose range, not a failure to meet it. C is wrong because a control limit is a statistical boundary on a control chart that separates normal variation from unusual, special-cause variation. D is wrong because a sigma level is an overall rating of how capable a process is, worked out from its defect rate. Rule to remember: the specification is the target, a defect is a miss, control limits flag unusual variation, and the sigma level grades the whole process.
Question: An important precursor to the NCPM is:
Answer: B. A referral
Explanation:
B is correct. The Nutrition Care Process Model begins once someone is identified as needing nutrition care. That usually happens through a referral or a positive nutrition screen. The referral comes before the process starts and triggers the nutrition assessment. A is wrong because evidence-based data guides every step of the model rather than coming before it. C is wrong because a physician's diagnosis is not required: referrals can come from nurses, other health professionals, a screening process, or the client. D is wrong because the diet history is collected during nutrition assessment, so it is part of the process, not something that comes before it. Rule to remember: screening and referral start the process. Assessment, diagnosis, intervention, and monitoring and evaluation are the steps inside it.
Start by reading CDR's RD handbook so you know the rules, how to book, and the timing before you study any content. Then take the main practice test without preparing, to see where you stand, and note which topics cost you the most points.
For every question you miss, write down the rule that would have led you to the right answer, not just the correct letter. Once your weak topics improve, do a full timed run of mixed sets, because the real exam gives you 3 hours. Book your appointment within your 1-year authorization, and check the details in CDR's handbook before test day.
The exam costs $250 per attempt. You pay the full amount by credit card when you book your exam appointment. The same fee applies each time you test. Refunds, rescheduling and retake rules are not covered here, so check the RD handbook at cdrnet.org before you book.
You need a scaled score of 25 on a scale from 1 to 50. This is a scaled score, not a percentage of questions answered correctly. Your score appears on the computer screen as soon as you finish, and the test administrator gives you a printed score report after you return the note board and other materials.
The exam has between 125 and 145 questions. Between 100 and 120 of them are scored, and 25 are unscored pretest questions mixed in with the rest. You have 3 hours once the timer starts, and the full appointment runs 3.5 hours. Because you can't tell which questions are pretest items, give every question your full effort.
Yes. Since January 1, 2024, the minimum degree to be eligible has been a graduate degree. You must also meet CDR's academic and supervised-practice criteria, which are checked in REPS. Once CDR approves you, you can test for 1 year at a time.
You can take the exam year-round, by appointment only, at Pearson VUE test centers. It is computer-based. You book a time once CDR has approved your eligibility, and you pay the $250 fee by credit card when you make the appointment.
You recertify by earning 75 CPEUs in each 5-year cycle, including 1 CPEU in ethics or health equity. Many states also have their own licensure rules, and these vary by state, so check with your state licensing board as well as CDR's recertification page.
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