Paid IRS after Audit. How does that impact my return for 2020?

[Ilan M Aliphas]

Hello,

I asked this question to my CPA and the answer didn't make sense to me.  Last year I got audited for my 2015 CA state tax return.  That year I did my taxes on Turbotax and fell for a misleading Turbotax trap. I had to pay a large amount of taxes in 2020 for this 2015 mistake – let's round it to $10k just for argument sake.  

Can I deduct those $10k on my 2020 Federal Tax return?  Is there any caveat like for example it depends on my total 2020 income?

Thanks in advance!!

Ilan