I had an error on my 2016 return and had to pay additional fed and state tax and penalties in 2018. How do I report this in turbotax for 2018?

[re2boys · Accepted solution]

You don't.  Penalties and interest is never a tax deduction.  The principle additional federal tax  paid is also not reportable at all.

However any additional state taxes (again, not penalties or interest) paid in 2018 is deductible on your 2018 federal itemized deductions.