An employer is only required to accommodate a "known" disability of a qualified applicant or employee. The requirement generally will be triggered by a request from an individual with a disability, who frequently will be able to suggest an appropriate accommodation. Accommodations must be made on an individual basis, because the nature and extent of a disabling condition and the requirements of a job will vary in each case. If the individual does not request an accommodation, the employer is not obligated to provide one except where an individual's known disability impairs his/her ability to know of, or effectively communicate a need for, an accommodation that is obvious to the employer. If a person with a disability requests, but cannot suggest, an appropriate accommodation, the employer and the individual should work together to identify one. There are also many public and private resources that can provide assistance without cost.
For additional information, take a look at the following resources:
Fact Sheet: Reasonable Accommodations in the Workplace