If you move to another state, you may be able to change the state where the custody case is being heard.  However, cases generally remain in the court where they began, especially if a lot of time has already been devoted to the case.  It may also depend on whether or not the other parent agrees or disagrees with the transfer.  This is a complicated issue, so it may be best to contact a lawyer if this applies to you.  See our MA Finding a Lawyer page to find a lawyer or legal services organization near you.