What age can a child decide which parent they want to live with in the state of IOWA

Actually the children don't decide, however, the judge will listen to all parties concerned (mother, father, children) and make a decision based on the best interest of the child.

At NO age can a child decide who they want to live with. In all states the decision is made by a Family Court judge based on what they feel is the best interests of the child.

The judge will listen to what the child wants. But the judge will make the ulitmate decision.

In any case, a petition has to be filed by one of the parents to modify the custody agreement.