Will there still be a penalty for not having insurance after President Trump signed the executive order to do away with it?

[Opus 17]

So far the executive order is only symbolic.  Nothing has actually changed yet, and no one knows what those changes will be.  And tax changes are rarely retroactive, so it is doubtful anything will be changed for 2016 taxes.  If it is, we won't know for a long time, and if something does change, you would be able to file an amended return.

(The order directs executive branch agencies to ease the burdens of the ACA to the "fullest extent allowed by law."  So it seems to be aimed at changing those rules that were put in place by executive order that extended or went beyond the written law.  So far the written law hasn't actually changed.)

[DoninGA]

Sorry, it does not work that way.  The ACA is a law that has to be either repealed or changed by Congress.  Then the President has to sign the legislation to make it law.