When couples with children under the age of majority separate or file for divorce, one of their top priorities is often to address custody arrangements. The parties can seek either joint or full custody arrangements, depending upon what their desires and needs are. The family courts hope that couples can come to an agreement regarding custody on their own, but in the event that they are unable to, they have the power to step in. Courts have an obligation to award custody arrangements which provide the greatest benefit to the children involved. Custody agreements remain in force until the children reach the age of majority, which is generally 18 in most states. Some custody arrangements remain unchanged; others require modifications when circumstances change between one or both parents.