Since the code 8 From 1099-R shows a taxable amount in box 2a, report under Less Common Income only the difference between the amount in box 2a of the code 8 Form 1099-R and the excess contribution that this loss-adjusted amount represents. This will result in an addition to the amount on Form 1040 line 1 of exactly the amount of the excess. Nothing else regarding any of this should add to income. The result will be equivalent to what line 1 would have had had the excess elective deferral never been made and had instead appeared in box 1 of your W-2.
