Fers Vs Csrs Retirement Understanding the differences between FERS (Federal Employees Retirement System) and CSRS (Civil Service Retirement System) is critical for federal employees planning their retirement. CSRS, a legacy system, offers a defined benefit pension and excludes Social Security benefits, whereas FERS combines a smaller pension with Social Security and the Thrift Savings... https://www.federalpensionadvisors.com/post/csrs-vs-fers