The American Board of Radiology certifies medical doctors to practice radiology in North America. Certificates are issued to candidates who have demonstrated their knowledge and proficiency by successfully completing comprehensive written and oral examinations. Nine primary certificates are offered in three fields of radiology: one certificate each for Diagnostic Radiology and Radiation Oncology, and three separate certificates covering Radiologic Physics and its subfields. In addition to the primary certificates, four Diagnostic Radiology subspecialty certificates are offered; namely Neuroradiology, Nuclear Radiology, Pediatric Radiology, and Vascular and Interventional Radiology. Since all categories of certification now issue 10-year, time-limited certificates the ABR has developed a maintenance of certification program called ABR-MOC. Guidelines have been established for all fields of radiology, and the program continues to evolve. All radiologists are encouraged to participate. Those who were issued time-limited certificates are automatically enrolled in the program. Throughout its history, the ABR has discontinued certain certifications as radiology techniques have changed. Please select Discontinued Certificates to view the list, which includes a description of the certificate time period during which each certificate was issued.