Received CP11 balance due notice for 2025 IRS taxes. How do I determine the specific details of my mistake?

[Bsch4477]

Review the “What we changed on your return” section of your notice. For more information about the errors on your return, call us at the number shown in the “Where to find more information”.

[Mike9241]

can't be for 2025 taxes because that return won't be filed until 2026. it it actually says 2025 txes it's likely a scam

FROM THE IRS

Read your notice carefully to see what was changed on your return and how those changes affected the amount you owe.

If you agree with the changes we made
Pay the amount owed by the date shown on your notice to avoid additional penalties and interest.
Make arrangements to pay over time if you can't pay the full amount right now.
Correct the copy of your tax return that you kept for your records, but do not send it to us. (if this is for your 2024 return, and you do this it is unknown how this will affect your e-filing for the 2025 tax return because the prior year AGI may no longer be what was on the return that was filed. you should be able to use the amended return approach without issue but don't file it unless there are new changes) 
If you disagree with the changes we made contact us at the number shown in “What to do if you disagree with our changes” by the date shown on your notice to have the changes reversed.

[xmasbaby0]

https://www.irs.gov/individuals/understanding-your-cp11-notice

Read the notice very carefully---it should tell you what the IRS changed.    The notice should also include a phone number that you can call to ask questions or to discuss the notice if you disagree with the change.

TurboTax does not get any information from the IRS after you file your tax return, so no one at TT knows what the IRS changed.