The Registration Examination for Dietitians is the exam between a completed dietetics pathway and the RD credential; the Commission on Dietetic Registration (CDR) administers it and grants the Registered Dietitian (RD) and Registered Dietitian Nutritionist (RDN) credential once the eligibility requirements and the examination are complete.
Should I take the RD exam before or after January 1, 2027?
It depends on when you can be ready. Your test date decides the outline: the Commission on Dietetic Registration's 2022–2026 outline applies through December 31, 2026, and its 2027–2031 outline from January 1, 2027. If you are ready on the 2022–2026 outline and can schedule your exam by December 31, 2026, testing then means you do not have to switch outlines. If you would sit the exam from January 1, 2027 anyway, study the 2027–2031 outline now. If you establish eligibility on or after January 1, 2027, CDR also limits you to eight lifetime attempts.
What changes between 2022–2026 and 2027–2031
The Commission on Dietetic Registration's 2027–2031 test specifications are effective from January 1, 2027. The domains below are compared by domain number; a matching number does not mean the same subject.
| Domain | 2022–2026 | 2027–2031 | Change |
|---|---|---|---|
| I | Principles of Dietetics, 21% | Fundamentals of Dietetics Practice, 23% | +2 points |
| II | Nutrition Care for Individuals and Groups, 45% | Community and Public Health Nutrition, 22% | -23 points |
| III | Management of Food and Nutrition Programs and Services, 21% | Human Nutrition and Medical Nutrition Therapy, 40% | +19 points |
| IV | Foodservice Systems, 13% | Food Science and Food Systems, 15% | +2 points |
Domain titles only in 2022–2026: Principles of Dietetics; Nutrition Care for Individuals and Groups; Management of Food and Nutrition Programs and Services; Foodservice Systems.
Domain titles only in 2027–2031: Fundamentals of Dietetics Practice; Community and Public Health Nutrition; Human Nutrition and Medical Nutrition Therapy; Food Science and Food Systems.
If you studied the 2022–2026 outline
The study guide lists both outlines topic by topic, in the board's order, so you can check what you studied against the 2027–2031 outline.
MasteryEngine asks which outline you are studying. Pick the outline for the year you sit the exam. Progress carries over only on topics both outlines share. A MasteryEngine plan for the RD exam is not tied to one outline, so switching outlines never costs extra. The MasteryEngine RD exam question bank is not open yet.
Scheduling and attempt limits
- CDR offers the RD exam year-round at more than 250 Pearson test centers, and appointment availability varies by center (CDR Registration Examination for Dietitians overview, checked October 21, 2026).
- In May 2026 the CDR board limited candidates who establish eligibility on or after January 1, 2027 to eight lifetime attempts (CDR Registration Examination for Dietitians overview, checked October 21, 2026).
RD exam prepRD exam study planRD exam study guide
The MasteryEngine readiness check for the RD exam opens when its question bank does.
MasteryEngine is an independent exam-preparation platform and is not affiliated with, sponsored by, or endorsed by the Commission on Dietetic Registration (CDR) or the Academy of Nutrition and Dietetics. RD and RDN are credentials/marks of CDR; all certification names and trademarks are the property of their respective owners and are used for identification purposes only. MasteryEngine does not provide CDR continuing-education credit and does not guarantee exam eligibility or passing. For official exam information, visit cdrnet.org.
Sources: CDR Registration Examination for Dietitians overview. CDR examination resources. RD examination eligibility requirements. cdrnet.org. Registered Dietitian Examination Test Specifications January 1, 2022 – December 31, 2026. Registered Dietitian Examination Test Specifications and Study Outline January 1, 2027 – December 31, 2031.