A. The ADA permits an employer to refuse to hire an individual if she poses a direct threat to the health or safety of herself or others. A direct threat means a significant risk of substantial harm. The determination that there is a direct threat must be based on objective, factual evidence regarding an individual's present ability to perform essential functions of a job. An employer cannot refuse to hire you because of a slightly increased risk or because of fears that there might be a significant risk sometime in the future. The employer must also consider whether a risk can be eliminated or reduced to an acceptable level with a reasonable accommodation.
The Federal Communications Commission (FCC) enforces regulations covering telecommunication services. Title IV of the ADA covers telephone and television access for people with hearing and speech disabilities. It requires telephone and Internet companies to provide a nationwide system of telecommunications relay services that allow people with hearing and speech disabilities to communicate over the telephone.

The U.S. Department of Transportation enforces regulations governing transit, which includes ensuring that recipients of federal aid and state and local entities responsible for roadways and pedestrian facilities do not discriminate on the basis of disability in highway transportation programs or activities. The department also issues guidance to transit agencies on how to comply with the ADA to ensure that public transit vehicles and facilities are accessible.
Once you have been hired and started work, your employer cannot require that you take a medical examination or ask questions about your disability unless they are related to your job and necessary for the conduct of your employer's business. Your employer may conduct voluntary medical examinations that are part of an employee health program, and may provide medical information required by State workers' compensation laws to the agencies that administer such laws.