but if you were a Federal Employee prior to 1987, you worked when the CSRS system was in affect.

Here's a link. http://www.opm.gov/retire/pre/csrs/index.asp

Several options discussed, which include FERS also.

I'd try to call and speak with someone.

I am perhaps overly pessimistic about the customer service .....! Thanks for the link elleng.

Have had excellent experience w govt customer service, even IRS!!!

Its their JOB!

Social Security retirement which is a kettle of fish of a different color. Much will depend on when you worked for the IRS. If before 1987, you were in the CSRS system. Since you withdrew your contributions I'm guessing this is the case. There is, under some circumstances, a provision to re-deposit your contributions and get a federal pension. I don't know if you would qualify or not. But, if you were to draw a fed non covered pension, you might very well lower your Social Security benefits. Look up the rules for the CSRS pension system about redeposits.

Here is a link to his Q&A section at their forum FederalSoup. Just post a message and he usually responds within a very few days.

FedSoup

The Office of Personnel Management is probably the place that can BEST answer your question. My experience is that they do answer calls but I don't know the qualifications of the people that answer. If you can't get an answer through the personnel office assigned to your agency then try OPM. Their web site is:
OPM