Unlike the CD/download versions of TurboTax, it appears that the online version of TurboTax has a bit of a deficiency in that it does not automatically recognize the code D entry as indicating that you made contributions to a qualified retirement plan. You must answer Yes when asked if you contributed to a qualified retirement plan.
No, do not enter the code D amount again in the Retirement Savings Contributions Credit section, TurboTax already factors it in once you answer Yes to the first question and answer the other questions.
