The Ten Schools Admissions Organization is a group of private preparatory schools in the United States. Wikipedia

The Ten Schools Admissions Organization was established in 1966 and comprises Choate Rosemary Hall, Deerfield Academy, The Hill School, Hotchkiss School, Lawrenceville School, Loomis Chaffee School, Phillips Academy Andover, Phillips Exeter Academy, St. Paul's School, and Taft School. Wikipedia