May sick leave/vacation leave/comp time run concurrently with FMLA leave?

Yes as to sick leave and vacation leave; no as to comp time. Generally, an employer may require an employee to use accrued sick or vacation leave while the employee is on FMLA leave for his or her own or a family member’s serious health condition. This is true even where the employee does not want to use accrued leave for this purpose. Where the employer does not require the use of accrued leave, the employee may choose to substitute accrued paid sick or vacation leave for unpaid FMLA leave for a serious health condition. See 29 C.F.R. § 85.207(c).

For the birth or adoption of a child, an employer may require an employee to use accrued vacation or personal leave while the employee is on FMLA leave. It may not require an employee to use sick leave for this purpose. Again, if the employer does not require the use of accrued leave, the employee may choose to substitute accrued paid vacation or personal leave for unpaid FMLA leave for the birth or adoption of a child. See 29 C.F.R. § 85.207(b).

Compensatory time off accrued in accordance with the Fair Labor Standards Act may not run at the same time as unpaid FMLA leave under any circumstances. If an employee wishes to use accrued comp time to cover a period that would otherwise qualify for FMLA leave, the employer may not count such time off against the employee’s FMLA entitlement. See 29 C.F.R. § 85.207(i).