State tax filing

Contributions for a 529 Plan do not go anywhere on the Federal Return.  

 If you are not the "participant" in the Iowa 529 plan, you may not deduct your contributions to that plan.

"Only contributions to these two Iowa 529 plans qualify for a deduction on the Iowa return; however, a rollover from another state's 529 plan to one of the Iowa plans qualifies toward the deduction for Iowa income tax."

This may help for 2018. 

If you or your spouse participate in the College Savings Iowa 529 Plan (Iowa Educational Savings Plan Trust) or the Iowa Advisor 529 Plan, each may deduct an amount contributed not to exceed $3,188 per beneficiary. These are Iowa Section 529 Plans.

You must be the "participant" in the Iowa 529 plan in order to deduct your contributions. If you are not the "participant" in the Iowa 529 plan, you may not deduct your contributions to that plan."

Source:  https://tax.iowa.gov/expanded-instructions/other-adjustments-2   subparagraph (g)