Q: I am employed by the Defense Department under the Civil Service Retirement System. My service computation date is Dec. 17, 1977, and I will turn 62 on Nov. 16. Prior to entering civil service, I earned enough quarters to qualify for Social Security. I have not selected a retirement date, but I am considering Dec. 31 of this year or January 2011 to receive a payout from the National Security Personnel System. If I retire Dec. 31, I will be reimbursed for all of my annual leave, but after that reimbursement I would be limited to the maximum amount…