The IRS has said (https://www.irs.gov/tax-professionals/aca-information-center-for-tax-professionals) that it will not accept electronically filed returns for processing during the 2018 filing season (2017 returns) if the taxpayer fails to comply with the individual mandate. This means doing any of the following:
The IRS did not do this for 2016 returns. However, as it reviews 2016 returns that have been filed, it may send letters to taxpayers who did not indicate they had coverage, were exempt, or paid the penalty.
A capital loss that is not deductible because it exceeds the annual $3,000 capital loss ceiling. A carryover loss may be deducted from capital gains of later years plus up to $3,000 of ordinary income.