To find out if 2018 needs to be amended, I recommend first verifying what was filed by going to the IRS link to Get Transcripts. This will verify what they have for your record of account.
Next, if you do have to amend, you will need to follow the directions in this link for amending 2018 tax returns. Keep in mind that you need the rules for 2018. The steps to do this will be:
- clicking amend my return
- downloading the 2018 program
- adjusting the dividends
- printing the return as prepared by TurboTax for you
- mailing the paper return (I suggest by certified mail) to both the federal and state
The returns should be processed in approximately 16 weeks.
