Are you looking at short term or long term disability. Short term (if you have insurance for it at work) is generally very easy to get. Often they have a short waiting period about a week or so. Most policies will provide coverage for around 6 months.
If you are talking about social security, things do get a bit more difficult. I don't recall exactly, but when I was on, there was a 6 month period that had to pass before you could apply (had to be off work for 6 months), then, with your doctors blessing and some magical paperwork, you have to hope they approve you. I heard its often hard for cf'ers to get disability right away, but in my case I was approved immediately. It took a few months to get approved, and then they backpaid from when I applied. It can be a tough year though, as one has to live on very limited income, and for some period-no income at all.
They generally look at what your capabilities are, if you are able to work etc. Much comes down to your physician and how he or she feels. They will have a direct effect on the perception of your personal case. I had a super physician (who actually initiated all the paperwork for me--I was only 21, a bit dumb on the subject) who truly felt I couldn't work at the time. I was about 20% lung function at the time. I am now at about 35%, give or take, and my current doc says that is about the threashold for disability.
