FMLA doesn’t require employers to pay employees for their time off, although, many employers require that the employee use all sick, vacation, PTO, or other paid time off types as part of the 12 weeks they take for FMLA.  For example if you have 2 weeks vacation and you request FMLA for a medical condition, the first 2 weeks you are on FMLA will be paid as vacation, then the remaining 10 weeks of FMLA will be unpaid.  Check with your employer for their policy regarding paid time off and FMLA.