Q. I have been retired disability FERS because of injuries from Iraq war since 2009. About 14 months ago I applied to SSDI and was approved. At that time the SSA told me my SSDI should not effect my FERS retirement. I want to know for sure. A. What you were told by SSA was wrong. Your FERS annuity will be affected. Go to http://www.opm.gov/retirement-services/publications-forms/csrsfers-handbook/c061.pdf and scroll to Section 61B2.1-3 to learn how the reduction will be made.