As an employer, you may be tempted to ask your employees what prescription medications they use and whether their prescription drugs could affect their ability to perform their job. After all, you want to identify any potential safety and performance issues before they arise.

Be aware, however, that employers may ask about prescription medicine only in limited circumstances. The Americans with Disabilities Act (ADA) restricts employers from asking medical questions of applicants and employees. Asking about prescription medications clearly falls into the category of medical-related questions.

Under the ADA, an employer may ask a current employee about prescription medicine only when it’s job-related and consistent with business necessity. That means you may not ask all employees to disclose any medications they take. Instead, you need to determine the job positions for which prescription-related questions would be job-related and consistent with business necessity. Typically, those will be safety-sensitive positions, such as drivers, police officers, and heavy equipment operators. Employees in jobs that don’t face a significant job-related safety risk associated with the side effects of prescription medications should not be asked about their use of those drugs.

Remember that the ADA doesn’t permit employers to ask medical questions of job applicants. Only after a job offer has been extended to a candidate may you inquire about medical information or require the individual to undergo an examination. In addition, be certain to keep all medical information confidential and in files separate from your regular personnel files.