Can an employer be required to modify, adjust, or make other reasonable accommodations in the way a test is given to an applicant or employee with a disability?

Yes. Accommodations may be needed to assure that tests or examinations measure the actual skills, aptitudes, or other factors the test purports to measure rather than reflect limitations caused by the disability. Tests should be given to people who have sensory, speaking, or manual impairments in a format that does not require the use of the impaired skill, unless it is a job-related skill that the test is designed to measure.

For additional information, take a look at the following resource:

FAQ: Does the ADA require that an applicant or employee with a disability be qualified for the position?