You live in Iowa but you work in nebraska and they don't take enough out for your Iowa income tax what do you do?

You have to take the money out and save it - the company does not have to do so for you...

Most cos are prepared to withhold for more than one state, especially adjoining ones. Talk to your payroll dept about having what you need done...otherwise, as said previously, it is your responsibility to handle the tax impplications of what you decide, like where you live.