29 C.F.R. § 825.308

(a) 30-day rule. An employer may request recertification no more often than every 30 days and only in connection with an absence by the employee, unless paragraphs (b) or (c) of this section apply.

(b) More than 30 days. If the medical certification indicates that the minimum duration of the condition is more than 30 days, an employer must wait until that minimum duration expires before requesting a recertification, unless paragraph (c) of this section applies. For example, if the medical certification states that an employee will be unable to work, whether continuously or on an intermittent basis, for 40 days, the employer must wait 40 days before requesting a recertification. In all cases, an employer may request a recertification of a medical condition every six months in connection with an absence by the employee. Accordingly, even if the medical certification indicates that the employee will need intermittent or reduced schedule leave for a period in excess of six months (e.g., for a lifetime condition), the employer would be permitted to request recertification every six months in connection with an absence.

(c) Less than 30 days. An employer may request recertification in less than 30 days if:

(1) The employee requests an extension of leave;

(2) Circumstances described by the previous certification have changed significantly (e.g., the duration or frequency of the absence, the nature or severity of the illness, complications). For example, if a medical certification stated that an employee would need leave for one to two days when the employee suffered a migraine headache and the employee's absences for his or her last two migraines lasted four days each, then the increased duration of absence might constitute a significant change in circumstances allowing the employer to request a recertification in less than 30 days. Likewise, if an employee had a pattern of using unscheduled FMLA leave for migraines in conjunction with his or her scheduled days off, then the timing of the absences also might constitute a significant change in circumstances sufficient for an employer to request a recertification more frequently than every 30 days; or

(3) The employer receives information that casts doubt upon the employee's stated reason for the absence or the continuing validity of the certification. For example, if an employee is on FMLA leave for four weeks due to the employee's knee surgery, including recuperation, and the employee plays in company softball league games during the employee's third week of FMLA leave, such information might be sufficient to cast doubt upon the continuing validity of the certification allowing the employer to request a recertification in less than 30 days.

(d) Timing. The employee must provide the requested recertification to the employer within the time frame requested by the employer (which must allow at least 15 calendar days after the employer's request), unless it is not practicable under the particular circumstances to do so despite the employee's diligent, good faith efforts.

(e) Content. The employer may ask for the same information when obtaining recertification as that permitted for the original certification as set forth in § 825.306. The employee has the same obligations to participate and cooperate (including providing a complete and sufficient certification or adequate authorization to the health care provider) in the recertification process as in the initial certification process. See § 825.305(d). As part of the information allowed to be obtained on recertification for leave taken because of a serious health condition, the employer may provide the health care provider with a record of the employee's absence pattern and ask the health care provider if the serious health condition and need for leave is consistent with such a pattern.

(f) Any recertification requested by the employer shall be at the employee's expense unless the employer provides otherwise. No second or third opinion on recertification may be required.