I’m not sure why I am not able to add my contribution to my 401k under the retirement savings plan credit. My voluntary contributions to my 401k shows up in box 12 on my W2, but I received a mess

[dmertz]

Enter items shown in box 12 of your W-2 only in box 12 of TurboTax's W-2 form, nowhere else in TurboTax.  If you entered it elsewhere, go back and delete that other entry.  If you qualify for the Retirement Savings Contributions Credit, TurboTax will automatically pick up the contribution entry you made in box 12.