From IRS Pub 970, pg. 50:
Eligible postsecondary school. An eligible postsecondary school is generally any accredited public, nonprofit, or proprietary (privately owned profit-making) college, university, vocational school, or other postsecondary educational institution. Also, the institution must be eligible to participate in a student aid program administered by the U.S. Department of Education. Virtually all accredited postsecondary institutions meet this definition. The educational institution should be able to tell you if it’s an eligible educational institution.