In January 2005, ACS (International) officially opened to the public. A completely private school, it took students from both Singapore and other countries. Its students take the International General Certificate of Secondary Education in their fourth year, then go on to take a two-year International Baccalaureate diploma from 2007 onwards. Before that, they take the International A-Levels. ACS(I) was officially authorised by the International Baccalaureate Organisation to offer the IB Diploma Programme in January 2006. and is recognised as an IB World School.