The Association of Christian Schools International (ACSI) is the largest Protestant educational organization in the world. Since 1978, ACSI has advanced excellence in Christian schools by enhancing the professional and personal development of Christian educators and providing support functions for Christian schools. Those functions include a host of services, including teacher and administrator certification, school accreditation, legal/legislative help, and textbook publishing. ACSI member schools serve more than 5.5 million students worldwide. Along with a headquarters facility, ACSI has 25 offices in North America and around the globe. Nearly 24,000 schools from over 100 countries are members. The primary financial support for ACSI is from 3,300 US-based schools. ACSI is a 501(c)(3) religious nonprofit organization.