If you used the desktop version of TTX 2017 to file your return and/or to amend your 2017 return, and you used the desktop version of TTX 2018 to complete your 2018 return, the only possible way to "update" the stuff imported from the 2017 return is to delete the .tax2018 file in the documents/turbotax directory and start over from scratch. That's the only way possible to import the corrected data from your 2017 tax file.
If you are attempting to e-file your 2018 return and the program is asking for your 2017 AGI, try three numbres.
First, use the AGI off line 37 of your *ORIGINALLY* filed form 1040 or line 4 of the 1040-EZ. That same amount is also on the 1040-X line 1, column A.
If that doesn't work then use the AGI on the 1040-X line 1 column C.
If that doesn't work then when asked for the AGI, enter a zero.
If tha doesn't work, then you have no other choice but to print, sign and mail it to the IRS.
