Hi I'm under the traditional and roth IRA contribution section. Is this where I put my 401K contributions?

[dmbaker1111]

Hi I'm under the traditional and roth IRA contribution section. Is this where I put my 401K contributions? Or is it already factored into my 401K?

[rainydaze]

Your 401k contributions have already been accounted for on your W-2.  Do not enter your 401k contributions in the IRA section, as it will cause errors.  

[turnthecorner]

I see that my 401(k) is on my W-2. How does that account for it as tax deductible? Other deductions appear on their respective 1099* tax forms and we still have to record them in our tax returns. 

[turnthecorner]

My bad. Re-read your post. The 401(k) contribution is in its own W-2 AND reflected in in Box 1 income. My bad. 

[JamesG1]

Box 1 of your W-2 will be lower than the amounts in boxes 3 and 5 by the amount of your pre-tax 401K contributions in box 12 code D.

So you recognize that the 401K contributions are pre-tax when you enter the box 1 number into your tax return.

(It is always possible that your individual W-2 has other codes or issues that affect these numbers.)

See also here.