Pursuant to A.R.S.§25-503(O) a child is emancipated:

1. On the date of the Child's marriage
2. On the child's eighteenth birthday
3. When the child is adopted
4. When the child dies
5. On the termination of the support obligation if support is extended beyond the age of majority pursuant to §25-501, subsection A or §25-320, subsections E and F.

Additional Reference:

An order stopping an income withholding order is appropriate when all children emancipate pursuant to A.R.S. §25-501A which states "If a child reaches the age of majority while the child is attending high school or a certified high school equivalency program, support shall continue to be provided while the child is actually attending high school or equivalency program but only until the child reaches nineteen years of age unless the court enters an order pursuant to section §25:320 subsection E."

Pursuant to A.R.S.§12-2451 and effective August 12, 2005, a minor who is at least 16 years of age, a resident of this state, self-sufficient, acknowledges an understanding of the obligations of an emancipated minor, and is not a dependent of the state may file a petition for an Emancipation Order. If the Order is granted the parental rights of the parents of that emancipated minor are terminated, including the obligation to pay child support.