Imagine that you and your spouse have a child, and for many years your family lives happily. But then something changes one day, and you and your spouse feel more stressed out and get into more arguments with one another. As the months pass, your marriage disintegrates, and you and your spouse decide that it is time to get a divorce.
Obviously, this is a trying time, but thankfully you and your spouse don't contest custody of your child, leading to joint custody that benefits everyone involved. A few years pass and everything under this arrangement is working out just fine.
But then your spouse informs you that he or she is getting a new job that will take her out of the state. What do the two of you do? How does custody work now that the two of you will be living in different states?
Interstate custody is indeed complicated, but that doesn't mean it is an insurmountable hurdle. There are laws that apply to almost every state in order to ensure a fair and balanced child custody system in case of interstate disputes. The state that makes the determination on the dispute is usually the child's home state, though there are certain circumstances where that may change (for example, if abuse or the child's safety is involved).
It is also important to realize that in addition to child custody arrangements being able to change, child support agreements can also be altered in light of a move or new life circumstances.
Source: FindLaw, "Interstate Custody Arrangements," Accessed July 30, 2015