Just want to clarify something Amy stated. If you fail the written boards, you do not "sit out" a year. You continue at whatever job you had and retake the exam the next year. The problem that many have is that they work more hours at their private practice job initially than they may have during the end of their residency. The further away you are from residency, the harder the exam is to pass (more money, more responsibility, more family commitments, more $ for more vacations, away from the educational environment, out of the study mode and difficult to get back into it, etc) so the miserable pass rate for retakers is understandable (below 50% of retakers pass-moral of the story, prepare and pass on first try).
So, while you don't sit out a year, your future may be in peril. Most groups have board certification as part of the requirement to become partner. So, not making it could cost you a couple hundred thousand, PER YEAR!! Not to mention the heartache that goes along with not passing it year after year. Pretty soon you realize that your kids are grown up and you missed it, and you're STILL not board certified. This scenario is not too uncommon.
Meanwhile, family med board certification pass rates have traditionally been in the high 90's.
So, finishing a residency in Family Med usually means you have the info to become board certified. Finishing anesthesiology...not necessarily. And we haven't even discussed the oral boards yet!
Trouble with standardized exams can be a real problem, and I believe that, more often than not, it is a warning sign for people that may struggle with the certification exam(of course, everyone knows someone who struggled with the USMLE but was an outstanding resident and killed the certification exam, but they are more the exception than the rule).
If I were the hubby, I would pursue a different residency. He, unfortunately, picked the field of anesthesiology at the height of its popularity(had he graduated in the late 90's and had a pulse, he could have gotten a spot). If he sits out a year, it will make it even more of an uphill climb for academic and financial reasons(you will be broke and hungry and nobody wants a candidate who has not been in clinical medicine for a couple of years, especially with the USMLE black marks)
It is my opinion that the ship has sailed for now on anesthesiology and waiting until next year will not make things better. It seems harsh, but I learned pretty early on that I didn't get to be an orthopod or dermatologist (not that I wanted to be). Maybe in a few years, things may be different for him.