Your employee claims that he has debilitating migraines. After he provided medical certification of his condition from his physician, you approved his request for intermittent FMLA leave to miss work whenever the condition occurs. You notice, however, that his migraines occur primarily before or after scheduled holidays or on Mondays and Fridays. You suspect that the employee may be abusing his FMLA leave. What, if anything, can you do?

First, you want to make sure the medical certification received from a doctor is legitimate. Contact the healthcare provider and verify that the doctor actually signed the certification form.

If the certification is genuine but you question its validity — some doctors will issue a certification based solely on a patient’s statements — you could also require the employee to obtain a second medical certification, if you are willing to pay for the cost of the examination.

But what should you do if you believe that the employee suffers from migraines, but that they are simply not occurring as often as the employee claims? Employers may initiate an internal investigation of the employee’s activities, including conducting witness interviews. Employers may also want to consider external surveillance if the employer believes the facts supporting abuse can be corroborated. For example, if your migraine sufferer is posting on social media when he is presumably suffering from a migraine, you would be justified in questioning whether he really was suffering from a migraine since migraine sufferers typically avoid light of any kind.

The most effective means of preventing abuse, however, is to have policies in place which curb the appeal of abusing FMLA leave, such as requiring employees use all paid-time-off before taking FMLA leave and uniformly enforcing notice of leave requirements.