Since TurboTax returns are considered to be self-prepared, you will need to calculate the amount of your Net Operating Loss. A negative AGI does not necessarily result in a Net Operating Loss Carryback/Carryover.
To access an NOL worksheet, please click on "How To Figure an NOL Carryover". Under "NOL Carryover From 2016 to 2017" you can click on Table 1 to access the worksheet.
To carry the loss forward, an election to forego the carryback should have been made with your 2016 return. Unless you filed your extended 2016 return in October 2017, you cannot amend your 2016 return to include the election.
"If you filed your original return on time but did not file the statement with it, you can make this choice on an amended return filed within 6 months of the due date of the return"
and
"If you do not file this statement on time, you cannot waive the carryback period."
This information can be found here. Click on "Waiving the Carryback Period" located two lines above "How to Claim an NOL Deduction" in the column on the left.
If you filed your extended 2016 return in October 2017, follow the instructions below to amend your return.
https://ttlc.intuit.com/replies/5567856
When you are ready to add the election to forego the carryback on your amended return, follow these instructions:
Type "nol elections, current year" in the search box in the upper right corner. This will give you a "Jump to" link.
In Forms mode, look for "IRC 172(b)(3)" to see the election.
If you did not file your extended 2016 return in October 2017, you will need to
carryback
your NOL.
Since TurboTax doesn't support Form 1045, you will need to prepare the Form 1045 to carryback the loss. Click here for the Form 1045 and click on Instructions for the how-to of preparing Form 1045.
