Child support does not always end after a child reaches the age of majority (18). In Illinois, child support traditionally ends upon a child's graduation from high school or 18th birthday, whichever occurs later. Adult children have the right to continued support for education or if they suffer from a physical or mental disability. Termination, otherwise known as emancipation, generally occurs when the adult child completes his/her education, marries, is living an independent life, or enlists in the military.