If TurboTax over forecasts my refund is the difference covered by the guarantee?

[xmasbaby0]

No.

TurboTax provides do-it-yourself tax software.  TurboTax guarantees the calculations done by its software.   The information entered into that software is data entered by you, the user.   TurboTax cannot and does not check that information against any outside sources, so TT cannot know if you entered your information completely or correctly.   It is up to you to enter all of your information correctly and completely, and to check your tax return before you file it.  If you forget to enter some income, or enter it incorrectly, enter it in the wrong place, etc. then you may end up owing additional tax to the IRS and/or state.  TurboTax does not pay the additional tax you owe.   If TurboTax’s calculations were incorrect, and you owe penalties and/or interest, then TT will pay the penalties and interest.  The tax due is always owed by you, and must be paid by you.

If you need to enter a claim for the accuracy guarantee:

https://ttlc.intuit.com/turbotax-support/en-us/help-article/intuit-account-billing/submit-claim-turb...

[danas200]

Additional information, my My state of Oregon told me TurboTax software made a mistake by drawing information from the wrong data source.  That's why my refund was reduced.  The software drew information from the federal return rather than the state return and so my refund was doubled.  

[danas200]

The state of Oregon acknowledges the mistake TurboTax software made by drawing information from the federal return rather than the state return. It was not my data input that made the mistake

[danas200]

It was not I who entered in the data incorrectly it was the software reaching out to the wrong location to get the data to give the answer to my return.  

[taxlady28]

Submit a claim and it will be investigated.  If the fault is the software, then you will be reimbursed for any penalty or interest that was incurred.   You are still responsible for taxes owed.

https://ttlc.intuit.com/turbotax-support/en-us/help-article/intuit-account-billing/submit-claim-turb...

[Mike9241]

@danas200 doesn't matter. if your refund was reduced, had Turbotax made the correct calculation you would have gotten what Turbotax should have shown.  The only part the Turbotax accuracy guarantee covers is penalties and interest. Since your refund was reduced and you did not end up owing, there should have been no penalties or interest. Therefore, any claim you file against Turbotax will likely be rejected.