How many times can I attempt the USMLE?
In theory you can attempt it multiple times, but USMLE rules mandate that you should finish all three parts within a seven year span of time.
If I fail, can I retake the USMLE ?
Yes, if you fail, you can retake the USMLE. But if you pass with a low score, you are stuck with it forever and you cannot retake the exam.
What is a passing score on the USMLE ?
On the three point scale, a passing score is 188. On the two point scale a passing score is 75
What kind of score do I need to get a good residency position?
You should aim for something in the vicinity of 240 if you want to make sure you get a good offer. Anything over 220 can still fly. Below 200 life will be really difficult for you.
USMLE :
Gateway to an American Medical Career