PPACA's individual mandate, which took effect in 2014, requires individuals who don't qualify for one of the many exceptions to obtain acceptable health insurance coverage for themselves and their family members or face a penalty ("tax").
Beginning in 2015, individuals filing a tax return (Form 1040) for the previous tax year were required to indicate which members of their family (including themselves) had health insurance coverage for the year. Based on this information, the IRS assessed a tax for each nonexempt family member who did not have coverage. The IRS put systems in place for 2016 where individual tax returns that did not provide this health insurance coverage information would be labeled as "silent returns" and automatically rejected.
In a private meeting with tax preparation software companies on Feb. 3, 2017, however, the IRS indicated, effective Feb. 6, 2017, it would not automatically reject silent returns for 2016. Instead, silent returns would still be accepted and processed by the IRS.
Obviously, this change in processing returns does not eliminate the ACA's individual mandate penalty. The change in policy does mean, however, that returns will not automatically be rejected. Completely removing the individual mandate penalty (or reducing the penalty amount to $0) would require action by Congress. This change in processing individual returns, however, is clearly a move toward considerably less strict enforcement of the individual mandate.
When pressed as to whether the change meant that the IRS would not follow up and inquire about the filer's silence on health insurance status, the IRS clarified that it did, in fact, reserve the right to follow up on the subject. This, however, was a legally necessary response. Because if the IRS directly stated the that information was optional and that the IRS would not follow up on any silent forms, it would be a direct abdication of the IRS' responsibility (as part of the executive branch) under Article II of the U.S. Constitution to execute and enforce the laws created by Congress.