1) Allergy and Immunology
2) GI (there are fewer spots per applicants than cards)
5) Pulm/Critical Care
As for interventional cards, it is a separate one-year fellowship after you have completed the general cards fellowship. You will have to apply for it at the end of your cards fellowship. It is surprisingly not so competitive.
You Bump! You don't apply/go into to the interventional cardio or noninterventional one out of residency. Do you apply to the INTERVENTIONAL GI, TRANSPLANT (liver, pancreas, SI), MOTOLITY, ETC. during your residency? Everyone knows that GI is far more competitive than cardio. GI is often called the most lucrative and well-paid subspeciality with good life style in medicine.
I didn't include every specialty of IM. I put in what virtually everyone would consider the 3 most competitive (Cards, GI, A/I) as well as a couple that are also considered pretty competitive. If you think nephrology is the most competitive field, you must be taking more than just placebos
I would have to say it is almost a three way tie between AI/GI/Cards (in that order) AI first simply because the few number of spots. GI because everyone is starting to realize the greatness of endoscopy.
Yeah, Heme is a bit more competitive than Pulm & C.C., but not that much more.
Honestly I don't know where A&I fits in to this. It used to be very competitive several years ago but I'm not sure the market for A&I is what it used to be before the selective Histamine blockers were available.