New Member

IRA distribution on prior year nondeductible contribution

I made nondeductible contribution 10 years ago and converted all to ROTH IRA in 2020.  In 1099-R I received shows entire amount as Gross Distribution & Taxable amount and both box was checked.   I don't have to pay tax twice on my  nondeductible contribution.   Can I override box 2a?  I tried that, but it didn't make any difference on tax.  How to report this?