You're wrong about that, too.
http://www.opm.gov/s...al_procedural.asp
Social Security Deductions
Employees subject to the FERS or CSRS Offset systems are subject to Federal Insurance Contributions Act (FICA) deductions from their pay. (CSRS employees are not subject to FICA deductions.) Therefore, in any case involving a FERS or CSRS Offset employee, FICA deductions (which are offset against the total employee retirement deduction) must also be withheld.
http://www.opm.gov/r...re/fers/index.asp
Congress created the Federal Employees Retirement System (FERS) in 1986, and it became effective on January 1, 1987. Since that time, new Federal civilian employees who have retirement coverage are covered by FERS.
FERS is a retirement plan that provides benefits from three different sources: a Basic Benefit Plan, Social Security, and the Thrift Savings Plan (TSP). Two of the three parts of FERS (Social Security and the TSP) can go with you to your next job if you leave the Federal Government before retirement. The Basic Benefit and Social Security parts of FERS require you to pay your share each pay period. Your agency withholds the cost of the Basic Benefit and Social Security from your pay as payroll deductions. Your agency pays its part too. Then, after you retire, you receive annuity payments each month for the rest of your life.
HTH.
Cheers,
Scott.