I once knew a guy who was severely spastic, bound to a motorised wheelchair, could barely move or talk, but inside his head he was really smart and good with computers. Despite his complete disability, he was able to land a programming job with a company willing to accommodate for his disability, and he did very good work there.
Then the department where he worked was disbanded and everybody was laid off. All his coworkers got unemployment benefits, but he couldn't, because he was disabled. So he had to get disability instead. So he applied, and was told that this wasn't a new disability, so he had to apply for something for inborn disabilities, which was a slightly different agency. So he did, and was told that that was only for people who have never been able to work, and since he had had a job, it didn't apply to him.
Personally I think everybody who manages to work and make money despite their disability, should just be able to keep everything without losing their disability pay. We should be rewarding them, but instead we're punishing them.