Unexpected outcome when trying to amend my 2016 tax return

[yoli]

I have a new, corrected W-2 for 2016 and I'm attempting to amend my 2016 tax return I filed using TT Premier 2016. The new return is, in essence, more favorable to my with regards to taxes as it reflects the amount I paid as my 401K contribution, so I expect I'd be getting a refund as a result, but TT only allows me to enter the new W-2 information and it does not compare it to the old W-2 information, nor takes into account the taxes that I've already paid. As a result, instead of getting a refund, it tells me that I own a significant amount of money. TT also suggested that it'd automatically re-calculate and print any forms that need to be corrected as a result of the change, but that doesn't seem to be the case either. Surely I must be doing something wrong - could you help me figure out what?

Thank you!

[macuser_22]

Exactly what changed on the W-2?     Box 12 amounts for a 401(k) should have no effect on the tax at all unless the employer also reduced the amount of box 1 taxable income.

(Before amending be sure to save a copy of the original .tax2016 file so you can go back to the original - always work on a copy.)

[dmertz]

In TurboTax you need to replace the original W-2 with the corrected W-2.  You can do that by modifying the original W-2.  If you enter the corrected W-2 separately you must delete the original W-2.