In this strange world, believe it or not, but many people under the age of 18 want to get emancipated from their parents. Emancipation is basically a legal procedure where a child can declare him or herself legally responsible for themselves; in an emancipated state, the parents are no longer responsible (financially or otherwise) for their children. In any state, once a child turns 18, he or she becomes emancipated, i.e. an adult. Also, should a person under the age of 18 join the armed forces or gets married (with parental consent), the minor also becomes emancipated.
Still, in a handful of states, a minor can become emancipated simply by declaring him or herself so, and in other states, the minor must petition a court to gain emancipation status. Yet other states allow parents to give children emancipation status.
Once a minor becomes emancipated, he or she has to make his or her own medical decisions, can be sued, and has the right to buy or sell property and otherwise enter into contracts. An emancipated minor must also take care of his or her financial affairs. However, emancipation status does not relieve the minor of having to attend school, and in most cases, and emancipated minor must still get permission for his or her parents to marry.
Again, the law varies by state, and this is not a forum for going into the particulars of each state’s emancipation laws. You can check here for a list of the laws that apply to each state.