All federal employees who have completed at least 12 months of federal service.

The following employees are not covered:

• Public Health Service (PHS) Commissioned Corps Officers
• Employees with intermittent appointments
• Employees with temporary appointments of less than 12 months
• Individuals not appointed by the government, such as:
  • Intramural Research Training Award Fellows
  • Guest Researchers
  • Visiting Fellows
  • Special Volunteers