Uniform Child Custody Jurisdiction and Enforcement Act
Since 1997, the federal Uniform Child Custody Jurisdiction and Enforcement Act (UCCJEA) has dictated that a parent cannot file for custody unless his child has lived in the state for the last six months. The only state that has not adopted the UCCJEA is Massachusetts. If you file for divorce in any of the other 49 states, the court will not have jurisdiction to decide custody if your children have not lived there for six months before you file. The UCCJEA discourages parents from relocating pre-divorce to a state that might be more inclined to grant them full custody.
Parental Kidnapping Prevention Act
The UCCJEA governs interstate custody matters before a parent has filed for divorce, whereas another federal law, the Parental Kidnapping Prevention Act (PKPA), takes over after litigation has begun. Under the terms of the PKPA, if one state already has jurisdiction over the children – and this is the case as soon as a parent files for divorce – no other state has the right to intercede. The second state must give full faith and credit to the first state's jurisdiction. It can enforce another court's existing order but not modify it. This is true even for temporary custody orders. For example, if you file for divorce and the court gives you temporary custody while your divorce is pending and your spouse takes your child and runs to another state, the court in the neighboring state is obligated to cooperate in sending your child home to you.
Parental Relocation Laws
If your spouse is the custodial parent of your child, she can petition the court either during or after your divorce for permission to relocate with your child to another jurisdiction. If the court grants permission, the terms of your original decree or custody order change to accommodate the move, but your home state typically retains jurisdiction over your children. State laws differ considerably with regard to whether permission to move will be granted – no federal law governs this issue. Some states place the burden of proof on the custodial parent to establish that such a move is in the child's best interests. Others place the burden of proof on the non-custodial parent to prove that it is not. Some states are willing to change physical custody to the parent remaining behind so the children don't have to move too. Most jurisdictions have rules in place requiring notice to the non-custodial parent during a certain window of time before the move, and the non-custodial parent can then petition the court for an order to stop it.
The rules of the PKPA and UCCJEA change in the face of domestic violence issues. Both acts include provisions for a new state to take jurisdiction and make orders if either the parent or child is in danger in the state where they've lived for the past six months and they've fled for safety reasons. Another state might also be able to take jurisdiction if neither parent nor the child continues to live in the home state, but this is unlikely if your divorce is ongoing.