If you offer health insurance to your employees, most of your full time employees are eligible for an FSA. Business owners usually are not eligible. Employees who have HSAs can also have a Dependent Care FSA, but not a Medical FSA.
All eligible employees can enroll in an Medical FSA, but those who'd like to set up a Dependent Care FSA must satisfy some additional requirements, especially if they plan to use the FSA to care for an aging parent or a new baby.
For more information on FSA eligibility, click here.