I believe all federal employees hired after 1984 are under the Federal Employees Retirement System (FERS.) Those hired prior to 1984 had the option of staying under the Civil Service Retirement System (CSRS), or switching to FERS. Most stayed with CSRS.
(Yes I am a federal employee, and no, I don't make anything close to $149,000 per year.)
Ditto. And ditto.