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.
Debt secured by a principal residence or second home to the extent of the excess of fair market value over acquisition debt. An interest deduction is generally allowed for home equity debt up to $100,000 ($50,000 if married filing separately).