The opinion points out that an employer is entitled to know whether an employee’s absence or request for sick leave is due to legitimate medical reasons.

That means that an employer may ask an employee to justify the use of sick leave by providing a doctor’s note or other explanation as long as it has a policy of doing so for all employees, or where special circumstances justify more searching or detailed requests of certain employees.

The EEOC identified three situations in which an employer may require more documentation from one employee than from others:

When the employer receives information which causes it to have a reasonable belief that the employee has a medical condition that may make him or her unable to perform essential job functions or pose as direct threat.

To substantiate that the employee has a disability if the employee requests a reasonable accommodation and the disability or need for leave is not known or obvious.

When the employee requests longer periods of leave or is suspected of abusing sick leave (for example, and employer can have one set of procedures for employees who want to take one or two days of leave, but a different set of procedures for employees who are out sick for a week or more).

The opinion letter also advises employers that they may terminate employees who refuse to provide the requested information.

While this opinion addresses employer rights under the Americans with Disabilities Act, it does not separately identify issues under other various protected leave statutes.

Therefore, before you make your documentation request, do a separate analysis to make sure that you have the right to have that information in the case of employees taking leave under one of the many laws which allows them to take protected time off work.