If you did not include your infant as a dependent on your tax return, and you have filed your tax return, you'll need
to wait for your tax return to either be rejected or accepted, if it is rejected you can add your dependent, correct any other
errors on the return and resubmit it. If it is accepted, you will need to amend your return to include the
dependent. You cannot e-file an amended return as this cannot be
filed electronically. The form is only filed on paper, so it will need to
be printed and filed by mail. If there is an additional refund owed based on the added dependent, then once you print and mail your return the IRS will mail the additional refund to you by paper check.
Please see the following TurboTax FAQ for instructions on how to amend your 2016 tax
return in TurboTax.
https://ttlc.intuit.com/replies/3288565
