In child custody disputes in which the parents and children have significant contacts with more than one state—such as having homes in multiple states and spending significant amounts of time in multiple states—there may be a question of which state’s courts have jurisdiction over the child custody dispute (the authority to hear and decide the dispute). The Uniform Child Custody Jurisdiction Enforcement Act (UCCJEA) is a law adopted by most states (all but Massachusetts) that determines which state’s courts have jurisdiction to hear and decide a child custody dispute in such a situation.

Massachusetts is the only state that has not adopted the Uniform Child Custody Jurisdiction and Enforcement Act (UCCJEA), which provides a uniform legal framework for determining the appropriate jurisdiction for child custody disputes involving multiple states. Instead, Massachusetts uses its own set of laws and principles to determine jurisdiction in such cases. Generally, Massachusetts courts will assert jurisdiction over a child custody case if the state is considered the child's 'home state,' meaning the child has lived in Massachusetts with a parent for at least six consecutive months immediately prior to the commencement of the custody proceeding (or since birth for children younger than six months). Additionally, Massachusetts courts may claim jurisdiction if the child and at least one parent have significant connections with the state and there is substantial evidence concerning the child's care, protection, training, and personal relationships within Massachusetts. If another state has already made a custody determination, Massachusetts courts typically will recognize and enforce that determination unless doing so would violate the state's fundamental principles related to the protection of human rights and fundamental freedoms.