Prohibited discrimination may include, among other things, firing or refusing to hire someone based on a real or perceived disability, segregation, and harassment based on a disability. Covered entities are also required to provide reasonable accommodations to job applicants and employees with disabilities. A reasonable accommodation is a change in the way things are typically done that the person needs because of a disability, and can include, among other things, special equipment that allows the person to perform the job, scheduling changes, and changes to the way work assignments are chosen or communicated. An employer is not required to provide an accommodation that would involve undue hardship (significant difficulty or expense), and the individual who receives the accommodation must still perform the essential functions of the job and meet the normal performance requirements. An employee or applicant who currently engages in the illegal use of drugs is not considered qualified when a covered entity takes adverse action based on such use.