Ok...just for S&G's, here's a scenerio for ya'll. Let's say, for some unfortunate reason that you happened to fail the USMLE or COMLEX. I take it that you are able to retest at some point? I would hope so.
I cannot speak for the COMLEX but you are able to retake the USMLE if you fail it (NOT just if you are unhappy with your score). I believe there is a required period (2-3 months as I recall) before you can retest.
Yes you are able to retake COMLEX. In fact some schools put added pressure on you, and either won't let you continue your rotations or won't let you graduate until you pass either COMLEX I or II respectively.
As my wise and respected friend Billie pointed out, the Med Schools do put pressure on you to pass the COMLEX (or USMLE). In addition, even if the Med School will allow you graduate, many internships and residency programs will not allow you to begin unless both Step I and Step II of COMLEX (or USMLE) are completed. Yes, there really is no end to exams.
At UHS it is required to pass COMLEX I before starting the third year. It is also required that we pass COMLEX II to graduate. If you fail, you can retest, but UHS only allows 3 tries before you are dismissed (at least that is what the handbook says...I don't know if they would really dismiss you or not.)
DMU also requires that you pass COMLEX part I before you are allowed to start your rotations. I know that here (DMU) the second years take it the first week of June. If anyone fails, they can retake it in august. 97% pass rate last year