If you apply for any of the specialties above (plus others like Anesthesiology), you have to apply separately for your intern year program (except for some programs in your given specialty which have an intern year linked to that given hospital). In other words, the majority of people applying to Rads/Derm/RadOnc/etc will end up with two match results listed on their piece of paper in the envelope on match day: Intern Year and Advanced Program (the specialty you chose).
That said, you have two choices for this intern year. Actually, you sort of have three.
1. Academic Prelim Medicine - this is a classic "Medicine intern year" and you will work alongside all the Internal Medicine interns (people who applied to and matched for a 3 year internal medicine residency), and sometimes even being scutted out more than them because the higher-ups know you're only there for one year, and if you're going on to those other competitive specialties you must've done well in med school and are pretty competent (cheap labor). I would list these as a last resort, if at all. The only benefit they have is if you happen not to match into your specialty, at least you're spending a solid year working hard in an academic program and you can either try to weasel yourself into the Internal Medicine residency or at least gain a little cred among specialty program directors when you re-apply for your specialty the following year.
2. Community Prelim Medicine - these programs are found at smaller hospitals that may or may not be "affiliated" with academic institutions/medical schools. They often contain less desirable internal medicine residencies (and you will often find a good number of FMGs there) but they usually have some good teaching and more importantly are usually focused on being more efficient than huge academic centers, so you hopefully don't get stuck rounding from 8am until 5pm deliberating about the 18th most likely cause that the patient's Magnesium dropped from 2.0 to 1.9. Can be hit or miss, but it's still a medicine year and you'll still end up with a ton of medicine months, ICU/CCU month(s), etc. Few electives (maybe a month, more if you're lucky).
3. Transitional Year - Many of these are really nice deals. But be careful, because some "Transitional Year" programs still kinda suck and are as bad as or worse than prelim medicine years. They're usually at small hospitals too, and often in places that aren't particularly high on the list of desirable places to live (often found away from big city areas). But they give you a much more diverse (and laid back) intern year than a year of medicine. You often get anywhere from 3-6 months of electives, maybe a month or two of ED, may or may not have ICU, and only a couple (2-4, often) months of floor medicine (the difficult months). The intensity of the floor medicine months also varies from program to program. Ultimately, these places are very competitive because of how "chill" they usually are, and how much lower stress they are.
