Cedar Rapids Gazette: State revenue experts now project Iowans will see their individual federal income taxes decrease by nearly $1.8 billion in the 2018 tax year. But the federal changes could mean Iowans will pay an extra $373 million over three years in higher state income taxes due to Iowa’s federal deductibility law. Because Iowa allows taxpayers to fully deduct their federal taxes on their state income tax returns, revenue experts calculated the state will collect an extra $33 million in state income taxes this current budget year that ends June 30. That increase will be $148 million in fiscal 2019 and $192 million in fiscal 2020 when the federal changes are fully implemented.