When leave is taken for the employee’s own serious health condition or that of a family member, the employer may require that the employee provide certification from a health care provider containing the following information:
- Name, address, telephone and fax number of the health care provider and type of medical practice or specialty;
- Approximate date of onset of the serious health condition and its probable duration;
- Statement of medical facts to support the need for leave (may include information such as symptoms, diagnosis, hospitalization, prescribed medication, referrals for evaluation or treatment, or other regimen of treatment);
- If the employee is the patient, information sufficient to establish that the employee cannot perform the essential functions of the employee’s job, as well as the nature of any work restrictions, and the likely duration of the incapacity;
- If the patient is a covered family member with a serious health condition, information sufficient to establish that the family member is in need of care and an estimate of the frequency and duration of the leave required to provide the care;
- If intermittent or reduced leave is requested for planned medical treatment, information sufficient to establish the medical necessity for the intermittent or reduced leave and an estimate of the dates and duration of treatment and any period of recovery;
- If intermittent or reduced leave is requested for the employee’s serious health condition that may result in unforeseeable episodes of incapacity, information sufficient to establish the medical necessity for the intermittent or reduced leave and an estimate of the frequency and duration of the episodes of incapacity; and
- If intermittent or reduced leave is requested to care for a covered family member with a serious health condition, a statement that the leave is medically necessary to care for the family member and an estimate of the frequency and duration of the required leave.
“Health care provider” includes any of the following: doctors of medicine or osteopathy authorized to practice medicine or surgery in the state; podiatrists, dentists, clinical psychologists, optometrists, chiropractors, nurse practitioners, nurse-midwives, clinical social workers and physician assistants properly authorized to practice and perform within the scope of their practice; Christian Science Practitioners listed with the First Church of Christ, Scientist, in Boston (in such case a second or third opinion may be obtained from someone other than a Christian Science Practitioner); any health care provider from whom the employer’s group health plan’s benefits manager will accept certification of the existence of a serious health condition to substantiate a claim for benefits; and a health care provider practicing in a foreign country in accordance with the laws of that country and within the scope of that practice as defined by that country’s law.
The DOL has developed two forms for this purpose: Form WH-380E is for the employee’s own serious health condition, and Form WH-380F is for leave to care for a covered family member with a serious health condition. The use of these forms is optional, but highly recommended.
 29 C.F.R. § 825.306.