Q: How long does an employee have to work for the employer before they are eligible for FMLA leave? A: The employee must have been employed by the employer for at least 12 months (does not need to. be consecutive) AND have worked for at least 1,250 hours in the immediately preceding 12 months. Q: If I have to miss work due to National Guard or Reserve duty, will this affect my eligibility for FMLA.