I have a traditional IRA from a previous employer. I now make non-deductible contributions each year which I track. From my understanding, reporting these contributions on Form 8606 prevents double-tax on withdrawal in the future. However, you get a tax break (IRA deduction line 19) if you make these contributions deductible. So which is more beneficial? Yeah, you avoid a double tax but you get a tax break now.
I am just discovering form 8606, and have failed to file it 2018-2020. I already got the tax break for the deductible contributions I made for these years. If I decide to change this as non-deductible contributions via Form 8606 (as they were actually post-tax when I contributed), do I need to amend each year's tax return since I was overpaid (IRA deduction line 19)?
Thanks
