This article is from the Medical Education FAQ, by eric@wilkinson.com (Eric P. Wilkinson, M.D.)with numerous contributions by others.
An alternative to the transitional year for some is the "preliminary
year." Preliminary years come in two flavors, internal medicine and
surgery. Each of these preliminary years somewhat resembles the
rotating internships of old, but with a focus on either internal
medicine or surgery. Those programs that require a year of
post-graduate education before beginning residency may accept either
a transitional year or a preliminary year. Obviously, surgical
residencies will require that you do a preliminary surgery year
while some other specialties will prefer a preliminary medicine
year.
The other reason that a new M.D. would go into a preliminary year or
transitional year would be because he didn't match into the
specialty of his choice. The hopeful applicant then takes a
preliminary or transitional year in the hopes of improving his
chances and qualifications for the next year's residency match.
The term "categorical" is used largely to distinguish between the
interns who are doing a preiminary year and those who are already
accepted into the residency program. For instance, a general
surgery program may have 6 interns every year, but two of them may
doing surgery as a preliminary year. Those positions that are
already accepted into the whole surgical residency program are
called "categorical."
 
Continue to: