I have a 401K to enter but the system wont let me. My adjusted income is less than 63K so it should let me enter the 401k.

[IreneS]

You mean contributions to your 401K?  Are you self-employed?

[IreneS]

How much were you trying to enter?

[dmertz]

The $63,000 figure potentially applies to the deductibility of traditional IRA contributions, not in any way to 401(k) contributions.

[IreneS]

If you are talking about a self-employed retirement plan, please follow these steps:

1. Click on Business > Continue > I'll choose what I work on
   
2. In the Less Common Business Situations section, click the Start/Update box next to Self-employed Retirement.
   
3. On the screen, Self-Employed Retirement Plans, click Yes
   
4. On the Individual and Roth 401k plans screen, enter your amount in Elective deferrals.
5. If you want to calculate the maximum contribution, leave the contribution box blank and mark the Maximize Contribution to Individual 401k box.  TurboTax will calculate the maximum and you can come back and enter the amount by clicking the Review Contributions box on the Retirement Contributions screen.
   

[NOTE:  I enter a self-employed income of $63,000 and TurboTax calculated and accepted a contribution of $18,500.

If you're still having difficulty, please respond to this thread with additional details.

If you are an employee:

Contributions to your 401(k) are entered on your W-2.   The amount is shown in Box 12 with code  D.  It is the reason is box 1 is lower than box 3.