The "cost" or "basis" MAY be reported on the 1099-R in box 9b "Total employee contributions". However, the cost or basis is required to be kept by the taxpayer.
Your retirement plan administrator may know what the basis is of your retirement plan, so you should call them. If you get this number, write it down and keep it in your tax records, because if your plan is passed to another retirement plan administrator, this information may or may not be passed along to the new administrator.
Also look at prior tax returns, because the same amount for basis would be entered every year.
Note that of you enter zero for the cost or basis, then 100% of the distribution would be taxable.
For more information on New Jersey retirement plan taxation, please see http://www.state.nj.us/treasury/taxation/njit6.shtml .
***Background on Basis***
"Basis" in a retirement plan is also called "cost" or "contribution". In a word, it is the amount of after-tax dollars that the taxpayer contributed to the retirement plan over the years while he/she was employed.
When the taxpayer retires, then the pension or annuity from the retirement plan begins. As the payments are made to you, each payment consists of a little bit of that "basis" and a lot of the money that the company is contributing.
You don't owe tax on the "basis" that is paid to you each period, because the "basis" is after-tax dollars that you contributed - and you don't get taxed twice on the same money.
The employer's contribution is, of course, taxable. This means, for example, that if a taxpayer received $12,000 in pension payments, that perhaps only $11,600 might be taxable if $400 of the payments were the return of the "basis"..
