Social Security and CSRS
The Social Security calculator download mentioned below turns out to be highly accurate. There was only a $2/month difference between it's calculation and my actual benefit received.
This is just some information for those CSRS retirees who might become eligible for Social Security benefits due to other work or employment.
The Social Security web site has information and an online benefits calculator that handles this situation. You will need the information from your annual Social Security Statement in order to use the calculator.
The web site explaining the Windfall Elimination Provision (WEP) and the Government Pension Offset (GPO) is: http://www.ssa.gov/gpo-wep/
There are links to the calculator on that page. There is also a more accurate calculator you can download to your computer. Both give you the opportunity to create different Social Security retirement age scenarios so you can determine the differences in benefits for early vs. regular retirement ages.
The nice thing is that you do not have to decipher and understand all the in's and out's of these two restrictions in order to use the calculator. You just enter the requested information and it gives you the answers.