The FMLA allows you to ask your employee for a certification, a written statement from his doctor giving certain details of his illness, including the expected duration, the diagnosis and the treatment plan.

If you are dissatisfied, you can request a second certification from a doctor of your choice. The doctor cannot be regularly employed by you, however, and you will have to pay for this second opinion. If the first and second opinions conflict, you can get a third and final certification; this third opinion will be binding on both you and your employee.