No. Poor job performance may be unrelated to an employee’s intellectual disability and should generally be dealt with according to an employer’s existing quality performance policy. According to the EEOC, medical information can only be sought when an employer has a reasonable belief, based on objective evidence, that a medical condition may be the cause of the employee’s performance problems. Joey’s supervisor can ask why his performance has declined and may explore ways to improve his performance but may not ask Joey questions about his intellectual disability unless there is objective evidence that Joey’s poor performance is related to his disability.

Source: EEOC fact sheet: “Questions and Answers about Persons with Intellectual Disabilities in the Workplace and the Americans with Disabilities Act.”