Make sure that you inform him of the change before you've submitted a payment for the item you want to make changes to. You can only change the shipping method and cost on invoices that have not been paid and that are for listings that ended within the past 30 days.
1 Nebraska Department of Health and Human Services System. 301 Centennial Mall South. Lincoln, NE 68509.  The phone number to call the Nebraska Medicaid office is 855-632-7633 or in state call 402-471-3121.
You may contact Iowa Medicaid Member Services by phone or email. The phone number is 1-800-338-8366 or 515-256-4606 (when calling locally in the Des Moines area), Monday through Friday, 8 a.m. to 5 p.m.