I sense/ understand your frustration..IF the IRS correctly assess you ( otherwise you need to prove to the IRS that you are correct, with documentation) then your filed return needed correction -- perhaps you overlooked something. TurboTax is a piece of software that helps you prepare and file your return. It guarantees the mathematical accuracy based on your input. For sure sometimes and in very complicated cases, it can make mistake by not asking the right question and/or not understanding a nuanced reply -- but those are very rare. Perhaps , and especially if you disagree with the IRS, you need to visit your local tax professional for advice -- $30,000 is a lot of money
