If you have already filed and your tax return has been accepted by the IRS, then you will need to file an amended return (form 1040X) to add the 1098-T information that wasn't included on your original return. Note that amended returns must be printed and mailed, as they cannot be e-filed.
If your tax return has not been accepted yet, wait until to learn whether it is accepted or rejected before creating an amended return. If your return gets rejected, you will be able to make the changes and then re-submit it for e-file.
Below are steps to create and file an amended tax return in TurboTax:
https://ttlc.intuit.com/replies/7276605
I didn’t find anything re the ACA when filling the return out. What do I do now?
After you receive your refund -approximately three weeks after your return is accepted, you can amend your tax return, by filing Form 1040X. To do this, you will log back into TurboTax and select the option "I need to amend my tax return."
You can find more detailed instructions on that process here: How to amend a tax return in TurboTax.
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