College admissions in the United States refers to the process of applying for entrance to institutions of higher education for undergraduate study at one of the nation's 2,675 schools. Generally, the college search begins in the student's junior year of high school with most activity taking place during the senior year, although students at top high schools often begin the process during their sophomore year or earlier. In addition, there are considerable numbers of students who transfer from one college to another, as well as adults older than high school age who apply to college.