The first year of post-graduate training following medical school is called "internship." Medical school graduates in the first year of post-graduate training are called an "interns" regardless of what that first year of training consists. Your initial year could be one of the following: a Categorical Year, Transitional Year, or Preliminary Year.
In many specialties, graduates can go right into specialty training, but several require an intern year of more generalized training before specialty training; hence the Transitional and Preliminary Programs. When this occurs, students must apply and interview at both their specialty programs and their intern year programs, even though they will not begin their specialty training a year after their intern year. This has also made Preliminary and Transitional Programs highly competitive, as many of the very competitive specialties require these types of intern years before specialty training.
Some of the fields that require a basic training year before beginning residency include:
- Radiation Oncology
A Transitional Year is an intern experience that many fields require or prefer where the student experiences a global training before beginning residency training. In this training, the graduate would experience both surgical and internal medicine rotations and be well prepared to enter a specialty where a thorough understanding of pathology, physiology, and surgical procedures are necessary.
The alternative to the Transitional year for some is the Preliminary Year. Preliminary Programs are further divided into Internal Medicine or Surgery. Surgical specialties will obviously require a Surgical Preliminary Year, but other specialties, such as anesthesiology will accept either a Preliminary Year in Surgery or Internal Medicine.To learn more, check out their entire article at the DIT site.