A federal tax cut for some Iowans could cost them money at the state level. Right now, Iowans can deduct what they paid to the federal government on their state income tax return. State officials said late last week because of federal deductibility, Iowans would contribute 16-million additional dollars to the state's coffers by June 30th. That number would rise to more than $100 million in each of the next two fiscal years.