Please see this answer from rjs. Ignore the dates.
To prepare the statement to waive the carryback period for a net operating loss, using TurboTax Home & Business, do the following after you have entered your business income and expenses to produce the net operating loss.
- Click the Personal tab.
- Click Deductions & Credits.
- Click "I'll choose what I work on" or "Jump to a full list."
- On the screen "Your 2015 Deductions & Credits," scroll all the way down to the bottom and click the button that says "Done with Deductions."
- The next screen says "Let's Check Your Deductions and Credits." Click Continue.
- You may get some other screens at this point. Proceed through the interview until you get to the screen described in the next step.
- The next screen says "Let's Check Your NOL." It says that you may have a net operating loss, and asks "Do you have an NOL for 2015?" Select Yes and click Continue.
- The next screen asks "What would you like to do with your NOL?" and gives you three choices. Select "Carry the NOL forward to next year." Click Continue.
- The next screen tells you that the NOL election form will be included in your return. Click Continue. TurboTax prepares the necessary statement and includes it in your return. You do not have to enter any information for the statement.
Note that the statement to waive the carryback period must be included with a return that is filed on time