Waiving the Carryback Period
You can choose not to carry back your NOL. If you make this choice, then you can use your NOL only in the 20-year carryforward period. (This choice means you also choose not to carry back any alternative tax NOL.)
To make this choice, attach a statement to your original return filed by the due date (including extensions) for the NOL year. This statement must show that you are choosing to waive the carryback period under section 172(b)(3).
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 (excluding extensions). Attach a statement to your amended return, and write “Filed pursuant to section 301.9100-2” at the top of the statement.
Once you choose to waive the carryback period, it generally is irrevocable. If you choose to waive the carryback period for more than one NOL, you must make a separate choice and attach a separate statement for each NOL year.
