An IME or IMO is an exam by a doctor you choose who has some understanding of what the VA wants to see in a report. I got them for a mental health condition in Tampa because I did know a couple of shrinks and lawyers who directed me and helped me. Without them I would have been screwed. The VA decided very early on that I was a personality disorder with slight mental health issues and they just would not change their minds until one of their own dorks said I was bipolar and that meant automatic 30%. I worked with that and when I was fired due to my disability I went for TDIU. I was seeing non-VA shrinks who were pretty smart and they wrote reports for me that concluded that I was unemployable due to SC conditions. The TBI vs PTSD thing is a real problem for the VA and they would rather sweep it under the rug. My understanding is that TBI and PTSD are totally different and should get separate ratings.