Maybe this is not news to most people, but for whatever reason when I read about the Trump administration's changes to the tax code I was under the impression the penalty for not complying with the ACA individual mandate was no longer in effect starting 1/1/18. That's incorrect, it's actually 1/1/2019.
The ACA individual mandate is that part of the Obamacare legislation that says if you opt-out of having any kind of health insurance and don't qualify for any exceptions for not having it (like you prove you can't afford it, etc) then you have to pay a monthly tax penalty. That's due when you file your taxes.
And the penalty can really add up. And it was an unpleasant surprise when I realized since I didn't have health insurance in 2018 I would still be on the hook for the penalty. It actually goes away for 2019 filing.
This is besides the point of my feelings if this change is a good thing or not. I am still torn on that. But for any of us that for any number of reasons decided they can forgo health insurance for a full year, this is important to know as tax filing is upon us.