Your retirement plan contributions that you made through payroll deduction should show on your W-2, with a Code D in Box 12. TurboTax will pick up this amount when you enter your W-2, so there is no need to enter it again.
The IRA deduction is an entry you would make if you contributed to an IRA outside of your employer.
Here's more info:
**Mark the post that answers your question by clicking on "Mark as Best Answer"