dr.z said:
Exactly. I assume most doctors who apply gets in. You are not fully licensed physician just by graduating from medical school.
Well, you can be licensed after graduating medical school - that's what the board exams are for. In the old days, many physicians did not complete residency programs and went into practice straight out of school - that's what was termed General Practice, something which basically doesn't exist anymore.
Residencies are for board certification, which is essentially required for anything you want to do.
To answer the original question broadly, since it's such a broad question, programs range from 3 years (FP/IM etc) to a total of upwards of 7 years if you want to do a surgical subspecialty, and everything in between. Do all doctors get in? All doctors who pass the boards and fulfill basic requirements get into
some residency - if nothing else, a non-competitive family practice program. Plastic surgery, dermatology, things like this are extremely competitive - you need top board scores, letters of rec., clinical grades etc to get one of the very few spots. FP, Peds, IM, Psych - I would say at this point that if you pass everything you could get a spot
somewhere - maybe not your top choice.