Couldn't tell you exact facts and figures, but the trend in medicine has swung back to subspeciality care after the primary care emphasis of the early 90's. This is dependent on the nature of the residency program you enter, but most well regarded academic programs aim to get all their residents into fellowships. That's just the focus of medicine right now. So while there might be a composite percentage of which internists don't specialize, you have to interpret the stat carefully. The fraction of internists entering GI and cards is consistent every year since the number of fellowship spots don't change much nationally- they're very competitive and very limited. I believe 750 national spots of cards and I'm not sure for GI.
