I have made a non-deductible IRA contribution this year. I do not qualify to make a deductible contribution. As I understand it, when I withdraw the funds, hopefully in retirement, I will only pay tax on the accumulated growth, not the original investment. But how will I,
20/30/40 years from now, be able to prove that this was a nondeductible IRA, and therefore has a tax basis? I have other IRAs which were deductible that I made many years ago, and I expect to pay taxes on all my withdrawals from those, since they have no tax basis.
========================================= MODERATOR'S COMMENT: When you file your tax return include Form 8606 containing the amount of the nondeductible contribution. If you forget you can file just the 8606 later, but it's best to have it part of the tax return.
Keep a copy of your last filed 8606.