In order to become a Justice on the Supreme Court of the United States, an individual must be nominated by the President of the United States and approved by the Senate, with at least half of that body approving in the affirmative. Generally, a justice's qualifications are judged by the President and, most visibly, by a Senate hearing. There is no definitive qualification of age or experience that is a standard to be met; instead is a much more subjective process taken by the Senate, occasionally resulting in a sometimes controversial defeat of Presidential nominees.
The following list consists of past Supreme Court Justices since 1789 placed in the order in which they took the judicial oath of office.
... age of 18, 3.5% from 18 to 24, 22.3% from 25 to 44, 28.7% from 45 to 64, and 28.1% who are 65 years of age or older. The median age is 50 years. For every 100 females ...