Transitional is what they call a TRI (traditional rotating internship) — it’s just one year , and then yes those applicants have to reapply for another program in any speciality. They probably didn’t match into a full residency, or they applied to a transitional program because they weren’t sure what they wanted and want to use that year later to match into something else more competitive. Most residencies in most specialities will give you some (if not all) credit towards residency requirements for doing a transitional program, but not all (like anesthesia would count a transitional program as year 1 towards their 4 year requirement, but neurosurgery or emergency medicine might not).
Preliminary year can usually be in medicine, surgery, peds, sometimes even other specialities. Prelim year is needed for specialities like radiology, Derm, neuro anesthesia, etc. The first year (intern year) can be a “preliminary” year in either medicine, or surgery, or even pediatrics at one hospital, and then the specialty residency can start in another hospital. People who apply to a speciality like anesthesia for example, apply for a preliminary year in medicine or peds or surgery at many programs, but they also apply for anesthesia separately (so it’s like you double apply). You can match prelim year and not match anesthesia, or you can match anesthesia and not the prelim year, with the goal being is you have to match both at the same time to get a “full match.” If you match anesthesia (years 2-4), but no prelim year, you can’t really start your anesthesia program if you don’t do a prelim year first, so you may lose that anesthesia spot.
If you match just the prelim year, that’s great, because you have somewhere to go right away in July. It can count towards a primary care residency in medicine or a subspecialty like anesthesia. But if you only match prelim and not the subspecialty, it means you still have to apply for your speciality again during prelim year, and then you would just start the speciality like anesthesia that following July, so you wouldn’t really lose time, it just would suck to apply for residency, while you’re doing residency, because you’re so busy.
Some speciality programs will accept a “transitional” or TRI year instead of a prelim year to count as the intern year. They are pretty much equivalent except that a transitional year has many random rotations in different fields like surgery, medicine, peds, family medicine, ob, etc. In the DO world, a “TRI” used to exist but now after the merger all the old programs that were called TRI’s have become transitional programs (what it’s known as in the MD world). The goal of the TRI or transitional year is to expose you to different rotations and make you more well-rounded. For example a friend of mine who matched into Ophthalmology, did a transitional year at a community hospital because it was easier, closer to home, and she got to do peds and OB and some outpatient specialty clinic. She could have ranked a competitive work-horse difficult preliminary medicine program but she didn’t want to work crazy hours that first year lol, so instead ranked an easier transitional program, to be her intern year. Either way, ACGME accepts it and so did her Ophthalmology program, which she would start the following year.
The match list is confusing I know, so basically medicine preliminary is where people matched to their medicine preliminary year first (intern year or PGY-1) in one hospital, and then they will start they PGY-2 in another hospital program like Derm, rads, etc.
Most people, to make things easier, will hope to match into and apply however for “categorical” programs. For example, you can apply to anesthesia and do all four years in one hospital program (do your medicine or surgery or peds year in the same hospital as your anesthesia program). For categorical programs, you just match into “anesthesia” and it’s assumed you are doing your preliminary intern year in medicine or surgery or whatever, in that same hospital.
As for medicine primary, I am not 100% sure but I think what it is, is that there are some specific internal medicine programs that focus only on primary care and outpatient (like NYU has internal medicine primary care tracks), so, that is what the Medicine primary is (most likely).
hope that helps!
Some more info for you
General info:
For those looking to match into a U.S. residency, there's some lingo that should be understood about the first year of post-graduate training as
rk.md
And prelim vs transitional:
And an excellent article about TRI:
Once required of all osteopathic medical graduates, the rotating internship has become largely a last resort—but not entirely.
thedo.osteopathic.org
