What Do Categorical, Preliminary, Transitional and Advanced Years in Residency Mean?

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 a resident (the “intern year”). There are three internship possibilities: transitional year (TY), preliminary year (prelim), or categorical. For the non-categorical applicants, the TY/prelim year is followed by advanced years in residency.

Part of the Texas Medical Center – the world’s largest medical complex


Trainees complete their intern year and residency at the same institution. Consequently, applicants don’t have to secure an intern year separately from their residency. Instead, their program offers the full training necessary to acquire board certification in that particular discipline. Popular residencies with many categorical programs include internal medicine, psychiatry, pediatrics, emergency medicine, family medicine, anesthesiology, and OB/GYN.

So what’s the advantage of categorical programs? All your training is at one institution. You don’t have to worry about finishing an intern year and then having to move somewhere totally different for your residency. The application is also way easier (especially if you’re couples matching).


Advanced residencies can be thought of as the “actual” residency in non-categorical programs after completing a compatible intern year (either prelim or TY). Applicants apply for both their intern year and advanced residency simultaneously but separately. As a result, the application fees and interview trail costs can be compounded compared to categorical applicants. Additionally, because some of the more competitive applicants (from derm, radiology, etc.) also require a TY/prelim, the highly-coveted intern years tend to be extremely competitive.

So what happens if one doesn’t match an advanced program? They might at least match an intern year and then attempt to improve their application to reapply in the following year’s residency match. A stellar intern might improve their chances to match at the same institution for an advanced residency spot. Or so logic says. 😉

Popular advanced residencies include diagnostic radiology, radiology oncology, anesthesiology, dermatology, ophthalmology, and urology. But, again, remember that you have to complete a separate intern year (and apply separately).


Transitional programs can be thought of as a sampling of many disciplines. Trainees rotate through medical and surgical rotations, including oncology, pulmonology, anesthesiology, dermatology, radiology, rheumatology, neurology, infectious diseases, obstetrics/gynecology, and ophthalmology. Transitional years are for specialties where a thorough understanding of basic pathophysiology and procedures is needed.


In comparison, prelim programs are either in internal medicine or surgery and saturated with rotations in those fields. Medicine prelims spend most of their year on general medicine wards, medicine electives, or the MICU/CCU. Surgical prelims rotate through various surgical subspecialties – general, vascular, plastic, pediatric, trauma, colorectal, etc. So naturally, surgical prelim years are slated for those entering surgical fields like urology.


Some programs offer both categorical spots as well as advanced spots for the same specialty. For example, at the time of this writing, I’m a categorical resident in anesthesiology at Baylor College of Medicine (BCM). I’m doing my intern year and my three years of anesthesiology within the same hospital system; however, there are several “advanced” spots reserved for applicants who did their intern TY/prelim elsewhere and will matriculate to BCM for three years of anesthesia residency. In other words, BCM has both advanced and categorical positions for anesthesiology. Several other residencies follow a similar application structure. Some programs only offer advanced spots (thereby forcing you to find an intern year elsewhere). Some are only categorical. I strongly recommend using FREIDA to research program structures!

Please let me know if you have questions in the comments section below! 🙂

Related Articles


  1. Hello, so I wish to go into EM ultimately, but for EM, you’d need the SLOEs which I don’t have access to, as an IMG, and those carry quite the weight, as letters of recommendations do for other specialties. So my chances of getting into EM are slim to none, really. I then thought to apply for a TY or a prelim year and then try to get into EM the next year after my Intern year. In this case, will I be applying to an advanced program for EM, for the next year, if there’s a thing like that, or I’d have to apply for a categorical year and just start again. Also, would you advice for a TY or a prelim year.

    Thanks so much!

    • Hey Daph! Admittedly, the IMG process isn’t something I’m familiar with at all, but it sounds reasonable to try to land a TY/prelim year first and then go from there. After all, that’s your first step. Sometimes, programs where you do your TY/prelim year might be more interested in you as an “internal” candidate for whatever residency you ultimately choose to do, but it’s possible you might have to apply for an advanced program in EM.

      As far as tips, check out my podcast.

  2. Hello Rishi, I am planning to apply for prelim position along with categorical position in internal medicine, just to be safe.
    Can i apply in prelim and categorical position in internal medicine in same hospital? Will they know that i applied for both prelim and categorical position? and will that affect my chance of getting position in that hospital?

  3. I’ve seen a few Anesthesia Programs on Frieda that DO NOT REQUIRE a preliminary year, DO NOT OFFER preliminary year, but do OFFER ADVANCED…does this mean that they will accept students into their advance program who have been accepted elsewhere for prelim, and also offer catagorical positions? I’m assuming that they must if they do not require a preliminary year correct?

  4. Hi Dr. Kumar,

    Thank you for your help on this topic.

    Quick question, for *Anesthesiology residency* in specific, should I apply to prelim in IM only?
    (since surgery prelim is too specific for surgical subspecialties like Uro). Or should I email each individual program offering advanced positions in Anesthesia to tell me if they’d prefer my prelim to be in IM or Surgery?

    • If I had to pick, yes, I’d go for internal medicine preliminary years because I feel like you’d get the most relevant rotations to a career in anesthesiology.

  5. Hi DR.

    I have a couple of Q.
    1.can I apply to advance directly before prelim or transitional?
    1a. if this possible does it mean I got matched in a year from now and I have a spot ready once I get my internship?
    2.if I applied to advance and prelim or transitional at the same time, is it possible I match in both so I start an internship now and advance the next year directly?

    • Hey Asal!

      I don’t think it makes sense to apply to an advanced BEFORE an intern year (prelim/transitional) since you won’t be able to start it until you complete the PGY-1 year somewhere. The answer to question 2 is yes.

  6. Hello,

    I wanted to know if a prelim or transitional year could count toward an advanced program like preventive medicine?


  7. Hello! I know this is an old post but you seem to be answering comments still which is amazing, so thank you! I was wondering about how the transition from a preliminary year to a categorical residency works in Surgery. If you do a 1 or 2 year Surgery prelim and are lucky enough to get accepted into a categorical Surgery position do you start at PGY-1 of the categorical residency following your preliminary year? Or would you start at PGY-2 or 3 depending on if you had done a 1 or 2 year preliminary program?

    • Hey Josh! Although I can’t speak from personal experience, I’m pretty sure that you would essentially start at a PGY-2 level. Best to just ask the program(s) directly for confirmation!

  8. Hi Dr. Kumar,

    I’m a US IMG from a school in Pakistan, currently looking at applying next year for the match. What would you recommend doing to make my CV strong for Anesthesiology specifically?

    Also, am I correct in understanding that I must match into Anesthesia, I must first do either:
    i) Prelim match into medicine or surgery (Could be at ANY Hospital) then apply for a “Advanced” PGY-2 match into a different/same program for Anesthesia
    ii) Categorical Match into Anesthesia
    iii) Transitional year THEN PGY-2 Match?
    Thank you in advance for the help

    • I have no experience with IMG applications, but there’s nothing special about making a CV strong – have excellent test scores, do well on your rotations, have strong recommendation letters, etc.

      And yes, unless the system has changed since I applied, you are correct regarding the options you listed. 🙂

  9. what is the pros and cons of transitional year and prelim year over categorical?
    Why do people dont prefer? Is it because you have to study “extra years”?

    • It’s not a matter of studying extra years since they’re all one year. Not all programs have categorical residencies, so you’re stuck getting a preliminary/transitional year (PGY-1) somewhere and then matching separately to the advanced residency (PGY-2 and beyond) of your choosing. As far as difference between a transitional and preliminary year… it just depends on what the program you’re looking at has to offer in terms of rotations, compensation, benefits, etc.

  10. Hi Rishi.. i know this is a late post but i couldnt find in detail anywhere else about the these programs. I am an intenational MD ob/gyn looking to get into a residency/fellowship here. If i were to consider getting into a transitional year/ preliminary internship what should i apply for, medicine or surgery? thank you for your time.

    • Whatever you want – by virtue of your ob/gyn training, I’d imagine a surgical year is more in-tune with what you have and will be doing in the future.

  11. Hello!

    I realize that this is an old post, but I am currently working on my applications for residency. I want to do Surgery, and I am slightly confused about the option to apply to both Prelim and Categorical Surgery at the same hospital. What I want is categorical, but I want to also be considered for prelim in case the program doesn’t want to offer me the full position. Is this advisable? Or should I just apply to categorical only and prelim only? Thanks for your time.

    • Hello David! Applying to both categorical and prelim programs at the same program is fairly common. You’ll ultimately rank the categorical and prelim programs separately… as if you were applying to two DIFFERENT institutions. Best of luck!

  12. hi sir, thank you so much for your post. I am an IMG aspiring to become a cardio surgeon or neurosurgeon, I heard its like 5 years surgery and then 2 years of fellowship, does that mean I should concentrate only in surgery for now and get LOR and do research mainly from surgery and not cardio surgery so that my chances for surgery residency are increased? could you also outline the specialities am qualified to apply if I do surgery prelims and TY? and also outline the process to get neurosurgery?

    • Traditionally, neurosurgery is its own seven year residency whereas cardiothoracic surgery is five years of general surgery followed by three years of cardiothoracic surgery fellowship. I’d say do research in whatever (with the goal of being published in reputable journals) and find people who will write you strong LORs. Surgery prelims go on to various fields including urology, anesthesiology, radiology, and of course general surgery.

      • thank you, I came across a post recently saying that cardio surgery is declining and I should try for interventional cardiology as they intervene before referring to cardio surgeons and clear most of the cases. is that true? what is your opinion, sir?

        • Although interventional procedures are gaining popularity due to their minimally invasive techniques, people have said cardiothoracic surgery is a dying field for decades, and it hasn’t gone anywhere! CT surgeons do incredible work and will always be needed for complex cardiac surgery, intrathoracic non-cardiac (ie, lung resections), and even trauma. I’d say do whatever makes you happy. There will be work for everyone. 🙂

    • Hi Rishi!
      I really appreciate you are answering questions here. I have a question. If a candidate matches into prelim year, completes his intern year and now has to apply in match again. Would he go into advanced position or categorical position?
      1) If he goes into categorical position, would he start PGY 1 or PGY 2??
      2) If he goes into advanced position, would he start straightaway or would he wait for a year?? Since the other matched candidates would still take a year to complete their intern year!!

      Hope you understand the question

      • Hey Ali! I think I understand your question, but let me know if I missed something. If you’ve had the hypothetical situation of matching into a preliminary year but not into an advanced spot, then you’ll complete your preliminary year and apply again for advanced positions while you’re a PGY-1. If you match, then you’ll wait a year and start as a PGY-2. For example, if you’re an intern July 2020 – July 2021, you’ll apply sometime in fall-winter 2020, interview, and then match in March 2021, but your advanced training (PGY-2) won’t begin till July 2022 unless a program had some spot open up for whatever reason. Generally, these spots aren’t posted in public, so you’ll learn about them by word of mouth and talking to your program director.

        If you reapply for a categorical spot after completing your preliminary year, I think it depends on how much a program is willing to use your preliminary year as credit. It’s possible that you might have to repeat this year as part of the categorical program, but again, needs to be discussed with the program director(s). In this case, your preliminary year is really only helping you get strong recommendations for a more stellar application the next time you apply.

        Hope this helps!

  13. Hey, it is a very helpful and awesome work you are doing.

    I have few queries:
    1. Will it be easy to get into the preliminary internal medicine program than to enter in the categorical? Is there a lot of rush or not?
    2. Do we get paid in the preliminary program? If, yes approx. how much?
    3. You said you need to apply for the advanced as well as preliminary program at the same time. So,

    a. If I am selected for the preliminary internal medicine program and categorical internal medicine program then can I leave the preliminary and directly enter into categorical?

    b. If I am selected for the both the prelims and the categorical and I choose to do the prelims, then do the entry for the categorical will be saved for me in the next year that is after completing the preliminary can I directly enter in the categorical program which selected me at the first time?

    c. If I do the preliminary internal medicine then can I apply again for the categorical after I complete it? And whether my chances of getting into categorical internal medicine program is increased and I can get into good residency program at the reapplying in match(reapplying is possible??) after doing my preliminary internal medicine program?

    I will be grateful to you. Thanking you in advance.

    • Hey Aditya,

      If you’re looking to do internal medicine, there’s no such thing as an “advanced spot.” Internal medicine programs everywhere are categorical. If you’re doing a speciality like dermatology, diagnostic radiology, radiation oncology, PM&R, neurology, psychiatry, anesthesiology, or urology, THEN you have the option of doing a prelim year at one program and then an advanced residency in that speciality elsewhere.

      You’ll get paid throughout residency (increases a little bit each year). At our program, first year residents start around $53,000 per year.

      Hope this helps! 🙂

      • Thanks Rishi, you are so helpful and frankly speaking I appreciate your working status and then also sparing time and doing this kind of stuff..bless you..

        Actually I had failed step1 and also I am IMG, so my chances of getting selected in the first try is quite low and definitely not in the good center .. So I was thinking to entering in the preliminary year once (also it is good as compare to sit the whole year ideal) and make my overall credits, including USCE strong….

        Also, plz tell, Will it be easy to get into the preliminary internal medicine program than to enter in the categorical? Is there a lot of rush or not?

        And the following:
        a. If I am selected for the preliminary internal medicine program and categorical internal medicine program then can I leave the preliminary and directly enter into categorical?

        b. If I am selected for the both the prelims and the categorical and I choose to do the prelims, then do the entry for the categorical will be saved for me in the next year that is after completing the preliminary can I directly enter in the categorical program which selected me at the first time?

        c. If I do the preliminary internal medicine then can I apply again for the categorical after I complete it? And whether my chances of getting into categorical internal medicine program is increased and I can get into good residency program at the reapplying in match(reapplying is possible??) after doing my preliminary internal medicine program?

  14. Hi, I want to apply to anesthesia residency, I have applied to some categorical positions! However i read your post, and have a confusion in my mind.
    -If I also apply through the non categorical route, ie, apply for a prelim year in IM, should I apply for advanced anesthesia programs right now!
    – And if I match into an advanced program now, does that mean that I am already matching into the pg year after my prelim year is over
    -one more confusion, if i match into advanced program but no prelim yr, then what are the choices or options!

    • Great questions, Kim! If you’re applying for separate prelim years, then yeah, you should apply for advanced anesthesia spots (otherwise what are you planning on doing once your intern prelim year is finished?) You’ll match to a prelim program *and* an advanced program separately, so you know where you’ll be for intern year and your anesthesia years on Match Day.

      If you match into an advanced program but no prelim year, then you will likely enter the “scramble” for an open prelim year. It’s better to apply broadly now, so you have a better chance of matching somewhere you like.

      • Many thanks for clearing my confusion! And that too so quickly!
        One more question, in the ERAS application, while applying for categorical anesthesia positions, I should also opt for advanced positions, but are these advanced positions for the anesthesia 1st residency yr starting july 2016.
        You said -separate prelim yrs!
        Unless i match into a categorical position in anesthesia, I shall have to apply for prelim yr in IM or Surgery! please correct me, if I am wrong!

        • The advanced positions you apply for are binding contracts beginning with your PGY-2 year. And you’re correct – matching into a categorical program in anesthesia means you’ll do your entire residency (intern year and anesthesia residency) in the same place. Otherwise, you need to match into a prelim year (PGY-1 year in either medicine or surgery) and separate advanced anesthesia program (PGY-2 through PGY-4). Hope this helps! =D

          • Hey Kim!

            I’d say that your decision to pursue a surgery or medicine prelim depends on your residency choice. For example, if you’re doing radiology, medicine is probably going to help more.

            Now comparing transitional years to prelim years… I honestly don’t know the data for IMGs (as far as which one has higher match rates). Maybe have an equal number of each to meet your maximum of 45?

            I would definitely modify your personal statement slightly just to make it more applicable to the position you’re applying for. You don’t need to change much, but at least avoid skewing your personal statement in a completely different direction from your prelim/transitional year.

          • Hi Rishi!
            How r u doing! I was a lil worried! Next week is Match week. And I have something to ask you! I might have to apply to preliminary programs or transitional year programs during SOAP, and I want to know, that being an IMG, and with a maximum of 45 applications, what kind of programs may help more- preliminary or transitional!
            -If preliminary, then medicine or surgery?
            – And do personal statements be modified according to or surgery prelim yr, or transitional year!
            I shall be grateful if you reply soon!

  15. Thank you for the post. I’m interested in either surgery or anesthesiology. Do I have to apply to the residencies and transitional at the same time? Thanks

    • I definitely would apply to both your transitional and advanced residencies together. This way you know on Match Day whether or not you have a job after intern year. =D

    • Hi! I think it’s amazing that you are still answering questions so I would like if you can solve my query.
      So if I get matched in a prelim/ transitional program and an advanced one in the same year(let’s say 2020 match) , does this mean that the advanced year will begin next year?

      • Yeah, you should have two separate match results (the prelim/transitional program and the advanced program). The idea would be that you finish your intern year (prelim/transitional program) and then will begin your advanced program.

  16. So, if a program only offers advanced spots, do you apply for those now or after you finish intern year?


Please enter your comment!
Please enter your name here

Try EchoTools - my free, iOS ultrasonography reference application!

Latest Articles