Sometimes they'll refer to MS1 as "freshman" year. But it usually doesn't matter, since MS1s and MS2s aren't signing any progress notes or patient charts.
An MS0 is what I was yesterday. Today I started med school :-/
But I have no problem with the term. Like others have stated here, I think its a useful term to distinguish on this board who is starting medical school next fall versus premeds who are still applying/haven't applied yet.
When I got to scrub in surgery with my research preceptor between 1st and 2nd year, I was called a "Baby Medical Student" by the scrub tech. I had been calling myself an "M one-two."
Well, not to be both anal and an ass, but only 15 (or so) of the EM residency programs use the PGY2-4 format (with a mandatory preliminary/transitional intern year). About as many use a PGY1-4 format, and the majority use a PGY1-3 format. In those cases E1=EM1=PGY1. 😳