After you file

Probably not.  But they will eventually send you a letter asking for it.  So you will need to amend.  You first need to wait until the IRS Accepts or Rejects your original  return.  If they reject it for some reason you can just fix it and resend it.  

If it was Accepted,  you need to wait for your return to be fully processed and you get the first refund or your tax due payment has cleared.   Then you can mail in an amended return.  Do NOT change anything yet on your return until you start the amended return.   If you have changed it then take out the changes and put it back to the way it was when you originally filed.  

 

How to Amend a 2016 Online return,

https://ttlc.intuit.com/questions/2952222-how-do-i-amend-the-2016-taxes-i-filed-with-turbotax-online 


You will still get your original refund or need to pay the first tax due. Then the amended return will only be for the difference you get back or need to pay back.  The Amended return will take up to 16 weeks to process and they only mail checks for refunds.