Reasonable accommodation at work?

The ADA explains that your employer must give you reasonable accommodations unless that would pose an undoable hardship. Most accommodations are obvious and are cheap or free to implement. You don't have to accept the first accommodation your employer offers, if it doesn't work for you. But sometimes you and your employer can't seem to find a good accommodation. What can you do then? 

It will help to look at the accommodations you have already tried, to see why they would not work. Brainstorming potential accommodations with an outside resource, such as JAN, Vocational Rehabilitation, or a job coach may turn up additional possibilities. Maybe it’s time to do a trial accommodation with one of their suggestions. 

Another option if you can’t be accommodated in your present job, a possible solution would be reassignment to a vacant job, or the creation of an entirely new job.