There are two types of FSAs, dependent care accounts and health care accounts.
All employees with qualified dependents may elect to enroll in a dependent care FSA, including most temporary employees. Annuitants are not eligible.
Employees whose appointment conveys eligibility for Federal Employees Health Benefits program coverage generally may elect to enroll in a health care FSA. This includes those temporary, seasonal and intermittent employees who are eligible for the FEHB if they are expected to work at 130 hours per month for at least 90 days (total, not annually).
Note: The U.S. Postal Service has a separate health care program for non-career employees; it also operates an FSA program that is separate from the FSAFeds program applying to other agencies, although their features are similar.
Participation, or lack of it, in the premium conversion program—through which FEHB premiums can be paid with pretax money—does not affect eligibility for FSAs. Nor does participation or lack of it in any other voluntary government benefit program.