The Americans with Disabilities Act (“ADA”) makes it unlawful for an employer to either require its employees to undergo medical examinations or make disability-related inquiries that cannot be justified as “job related and consistent with business necessity.” The statute, however, expressly provides that testing an employee for illegal drug use is not a “medical examination” that must be justified under this standard. But what about an employer, who, because of safety concerns, requires employees to be tested for substances for which the employee has a valid prescription? Does such a test constitute a medical examination or a disability-related inquiry? In Bates v. Dura Automotive Systems, Inc. , the United States Court of Appeals for the Sixth Circuit the Court concluded that whether testing for prescription drugs constitutes a medical examination or a disability-related inquiry for ADA purposes depends on the specific facts of the case at hand and, ultimately, may be an issue for a jury to resolve. It is clear that this is an area where employers must tread carefully.