Thanks, DaveF1006, for your help. I think my question should have been better phrased. This FERS supplement (distinct from the FERS annuity), also sometimes referred to as a Social Security Supplement, is a special provision designed to help public service officers forced to retire at 57 reach the minimum age to receive social security (typically age 62).
As such, it's not an annuity to which the retiree has contributed.
I've determined the supplement is fully taxable and will enter the 1099-R numbers exactly as they appear on the 1099-R (as you advised) with no reduction in the taxable amount. Thank you for your help!
