You were just given a link to get help with the letter from the IRS. And....no one knows at this point if TT made a mistake or if it was user error. ( Usually it is user error.) If TurboTax's calculations were not accurate there is an accuracy guarantee. TT never pays your extra tax owed, but if TT's mistake led to penalties they will pay them.
https://turbotax.intuit.com/corp/guarantees/
You can also call customer support.
To call TurboTax customer support
https://ttlc.intuit.com/questions/1899263-what-is-the-turbotax-phone-number
They are available from 5 a.m. to 5 p.m. Pacific time Monday-Friday
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
