As a pre-med that plans to specialize in an IM subspeciality(Critical Care Medicine) and all of this talk about COMLEX vs USMLE, I have a question. As someone that aspres to become an osteopathic physician, is it worthwhile to take both exams since this subspeciality is not “traditional” for D.O’s to specialize in?(Not many AOA approved residency programs either-I think maybe 3-5 if I’m not mistaken 
-and I’m looking to attend a CCM fellowship program anyway after the 3 yr IM residency). Thanks for the input!!!
Kim,
If you're trying to match into an IM program, I would not bother taking the USMLE. DOs enter ACGME IM programs in droves!
And, when applying to ACGME fellowships, once you've completed an ACGME residency and in manner to be sufficiently competitive for a fellowship position, the issue of COMLEX vs USMLE is a moot point. That is straight from the mouths of the DO peds cardiologists & DO PICU docs I have corresponded with on this very issue.
You do realize that at this point in time, you cannot mix AOA & ACGME training for residency & fellowships and meet either the AOA's or ACGME's subspecialty Board requirements.
The AOA does have lots of IM & some CCM fellowships. I am unsure of the #s though.
Dave,
Where would I find out info about AOA sponsored CCM fellowships? Thanks!!! 
Kim,
Here is the link for the AOA Opportunities page:
AOA Post Doctoral Training Catalog
And, this is the link to the AOA’s main page:
American Osteopathic Association
Follow these and peruse their info. It is not as advanced or helpful as the AMA’s FREIDA site…maybe it’ll grow up one day?