CDR Exam Explained: How to Prepare and Become a Registered Dietitian

Becoming a Registered Dietitian (RD) or Registered Dietitian Nutritionist (RDN) requires dedication, education, and one final step: passing the Commission on Dietetic Registration (CDR) exam. You must pass the CDR exam – also sometimes called the Registered Dietitian exam, the RD exam, the registration examination for dietitians, or the dietitian licensing exam – to be awarded your RD or RDN credential.

Most states require dietitians to be licensed, and the RD or RDN credential qualifies you for state licensure¹. When you pass the CDR exam, it shows that you’ve mastered the knowledge and skills needed for evidence-based nutrition care. This achievement marks the beginning of your career as a registered dietitian and opens doors to professional opportunities you’ve been working toward.​​​​​​​​​​​​​​​​

If you're preparing for the RD exam, it's important to know about the Commission on Dietetic Registration (CDR). The CDR is the organization that administers the exam, and the examination itself is called the CDR exam. The Commission on Dietetic Registration is the credentialing agency of the Academy of Nutrition and Dietetics. Formerly known as the American Dietetic Association, the Academy of Nutrition and Dietetics is a nonprofit association dedicated to enhancing national health and strengthening the dietetics profession².

The CDR establishes and enforces standards for dietetic professionals. Every RD credential it issues reflects not just a dietitian’s individual competence, but their commitment to evidence-based practice, ethics, and public safety³.

If you want to become a Registered Dietitian, you need to do the following to be eligible to take the CDR exam:

Another pathway to consider is to pursue a Master of Public Health (MPH) degree and RD credential through an MPH‑RD dual degree. ACEND-accredited MPH-RD programs integrate the required DPD coursework and supervised practice within your graduate-level training⁸.

After the CDR receives your verification statement, they’ll send you an Authorization to Test (ATT) email so that you can verify your identity and schedule your CDR exam. The exam is administered through the CDR’s testing partner, Pearson VUE. The fee is $250⁹.

The registered dietitian exam covers four areas:

The exam is administered in a computer-adaptive testing (CAT) format. That means that the questions are tailored to your individual level of competence. The CDR exam begins with a medium-difficulty question. Get it right, and your next question will be slightly harder. Get it wrong, and your next question will be slightly easier.

Based on your performance, you will need to answer 125 to 145 questions. You must complete at least 125 questions in order for the exam to be valid. Of the minimum 125 completed questions, the RD exam contains 25 unscored pretest questions. Although these pretest questions don’t count toward your score, you won’t know which ones they are, so it’s important to answer each question to the best of your ability.

You’ll have three hours for your RD exam, which includes a 20-minute tutorial, 2.5 hours of testing, and a 10-minute survey. Each question is multiple-choice, with four possible answers. You cannot skip, review, or change responses. A calculator is provided for use during the exam¹⁰.

You’ll need to bring a government-issued ID to the testing center. The name on your ID must match the name in the Pearson VUE scheduling system. Be sure to carefully review theRD Exam Candidate Handbook and any information you receive from Pearson VUE several days prior to the exam so that you know what to bring to the test center and what to expect on test day.

Taking the registered dietitian exam is a major milestone, and it’s natural to feel both excited and anxious about it. By implementing study strategies and taking advantage of exam resources, you can stay focused and be prepared for success.

As soon as you complete the exam, you’ll receive an official score report. This report will tell you right away whether you passed or failed¹². If you pass, the CDR automatically updates your record and, about 72 hours later, CDR staff will send you a fee notice by email. You’ll need to pay an $80 fee annually to receive and maintain your RD credential.

The next step is applying for state licensure, which is required in most states to practice as a dietitian. Each state has its own process, but typically you’ll submit your exam results, transcripts, and an application to the state licensing board. With your license, you can begin practice as an RD!

If you need to retake the exam, your score report will help identify areas to focus on before your next attempt.

Passing the CDR exam can position you to make a meaningful impact in public health. As a Registered Dietitian, you can lead community nutrition programs that address food security and maternal-child health or guide public policy to improve food systems and promote equitable access to nutritious foods. RDs are also central to chronic disease prevention, delivering evidence-based interventions to reduce population-wide risks of conditions like diabetes and heart disease. The interdisciplinary field of public health nutrition weaves together food systems, epidemiology, and behavior-change strategies. In roles such as public health nutritionist or program director, you can become the bridge between science and community well-being and help to transform public health¹³.