Hello,
When I read IRS Publication 536 for years 2017, 2018 & 2019, I have a better understanding.
"Waive the Carryback" was mandatory for NOL year 2017 & before because for NOL Year 2017, IRS pub 536 says:
"Generally, if you have an NOL for a tax year ending in 2017, you must carry back the entire amount of the NOL to the 2 tax years before the NOL year (the carryback period), and then carry forward any remaining NOL for up to 20 years after the NOL year (the carryforward period). You can, however, choose not to carry back an NOL and only carry it forward. See Waiving the Carryback Period, later. You cannot deduct any part of the NOL remaining after the 20-year carryforward period. NOL year. This is the year in which the NOL occurred."
But starting NOL year 2018, taxpayers were not even allowed to carryback except in certain situations like Farming Loss as the rule was abolished for NOL year 2018 because for NOL Year 2018, IRS pub 536 says:
"Generally, if you have an NOL for a tax year ending in 2018, you must carry the loss forward to future years. You may carry the losses forward indefinitely. NOL year. This is the year in which the NOL occurred. Exception to the No Carryback Rule Farming losses, defined next, qualify for a 2-year carryback period. Only the farming loss part of an NOL can be carried back 2 years."
The CARES act June 30, 2020 deadline for NOL year 2018 was introduced because carryback was disallowed for NOL year 2018 as explained above.
