If you have filed your 2015 tax return and it has been accepted by
the IRS, you will need to file an amended return to correct the 1099-B and 1099-DIV information. TurboTax will guide you
through correctly entering your new data and printing Form 1040X. You may also
have to amend your state income tax return if you have a state income tax.
Please note that amended tax returns must
be filed by mail.
For more information, please see TurboTax
Guide - Amending Your Income Tax Return.