Retirement tax questions

Thanks for your help. Another question Turbotax asks is whether I made any after-tax contributions. On the W-2, there is an amount in 12b marked with the code BB (Designated Roth contributions under a section 403[B] plan). Should I list that as an after-tax contribution? Turbotax says that if I enter an amount for this question, it will be like a correction to box 5 on the 1099-R.