Q. My agency committed an error by moving me from CSRS to FERS. After 18 months and senatorial support, it was finally resolved; the agency satisfied the debt; and I retired Dec. 29. I have since received W2-Cs for past three years. I am looking at a decrease of approximately $17,000 in Social Security taxes withheld for those three years. Those monies were pulled back and put into my CSRS account. If the Internal Revenue Service determines that there is now a tax liability after filing my amended returns, can I make an appeal to the Office of Personnel Management (under the provisions of Federal Erroneous Retirement Coverage Correction Act) to reimburse me for that liability?