 In respect to foster care, aging out is the process of a youth transitioning from the formal control of the foster care system towards independent living.It is used to describe anytime a foster youth leaves the varying factors of foster care, including home, school and financial systems.The United States Citizenship and Immigration Services defines an "aging out" case as, "a situation referring to a person's petition to become a permanent legal resident as a child, and in the time that passes during the processing of the application, the child turns 18 and ages out.