For a NJ return, how do I subtract the portion of a 403B distribution that represents after-tax (for NJ, not for Federal purposes) contributions?

The 1099-R does not indicate the amount, although I placed the correct taxable amount in the last Turbotax field labelled Taxable State amount.  The NJ form however is not picking that up and continues to use the Federal amount of the distribution (which was pre-tax_ and on which taxes are owed on the full amount.