I know that it says that in TurboTax, but it's wrong. You cannot use the amount from the portal. If you enter anything other than the amount in your own 6419 letter your tax return will be pulled for manual processing. Given the current state of the IRS backlog, that means that processing of your return will be delayed for many months. If you are getting a refund, you refund will be delayed. And when they finally process your tax return, you will get a notice from the IRS telling you that your tax return is wrong because you didn't enter the correct amount from your 6419 letter.
