I contributed $3k to a traditional IRA in March 2017 for tax year 2016. I reported $2080 - the deductible amount, and didn't report the nondeductible $920. What options?

[johnrr12]

I contributed $3000 to a traditional IRA in March 2017. I reported only $2080, the maximum deductible amount on my 2016 taxes. I did not report the non-deductible portion - $920. What are my options?

[dmertz · Accepted solution]

You must file Form 8606 to report the nondeductible traditional IRA contribution.

You can cause TurboTax to prepare the Form 8606 by using TurboTax to amend your 2016 tax return and telling TurboTax that you contributed $3,000 rather than $2,080.  If entering the full $3,000 changes the amount that TurboTax reports as your IRA deduction, you'll need to file the Form 8606 along with Form 1040X.  If the amount of your IRA deduction does not change, you can file the Form 8606 by itself (signing directly on Form 8606), although including Form 1040X gives you a place to provide explanation and to demonstrate that this change does not change your tax liability.