It would appear that you did not report it at all on your 2013 tax return. What you need to do is file a 2013 8606 form for a non-deductible 2013 contribution (it is too late to amend 2013 for a deduction).
Download the 2013 8606 and enter the 2013 contribution on line 1, any previous (before 2013) non-deductible basis from a previous 8606 line 14 on line 2. Add 1 & 2 on line 3 and 14.
(There is $50 penalty for failing to file the 8606 when required, but the IRS usually waives the penalty.)
2013 8606 - https://www.irs.gov/pub/irs-prior/f8606--2013.pdf
2013 instructions - https://www.irs.gov/pub/irs-prior/i8606--2013.pdf
Where to mail: https://www.irs.gov/uac/where-to-file-paper-tax-returns-with-or-without-a-payment
Keep the 8606 copy for when you take a distribution - you will need the line 14 value.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
