What you should know about nondeductible IRAs
Contribution limits
Nondeductible IRAs are subject to the same annual contribution limit as other IRAs. However, your contributions to a nondeductible IRA are made with after-tax dollars, while your contributions to a traditional IRA or 401(k) can be deducted in the year they’re made.
Withdrawing contributions
You can withdraw money contributed to a nondeductible IRA in retirement without paying taxes on it, though. Otherwise, you’d be taxed twice on those contributions. However, to let the IRS know that you’ve contributed with after-tax dollars, you must report your nondeductible IRA contributions each year using IRS Form 8606. This form is essential to ensure you aren’t taxed on the contributed money a second time when it’s withdrawn in retirement.