Mr Koh is presently the Chairman of the Housing & Development Board. He is also Chairman of the Singapore Deposit Insurance Corporation Limited. He sits on the Boards of Singapore Airlines Limited, CapitaLand Limited, UOL Group Ltd and Hotel Plaza Limited, companies listed on the SGX-ST. He is a director of Singapore Cooperation Enterprise and CapitaLand Hope Foundation. He was Deputy Chairman of the National Kidney Foundation from 2005 to 2007.

From 1997 to 2005, Mr Koh served as Chief Executive Officer of the Inland Revenue Authority of Singapore. In that capacity, he was both Commissioner of Inland Revenue and Commissioner of Charities.

Prior to these appointments, Mr Koh was the Permanent Secretary of National Development, (the then) Ministry of Community Development, and Ministry of Education. Mr Koh has substantial experience in public administration having served in the Ministries of Finance, National Development, Community Development, Education and the Prime Minister’s Office. He was awarded the Public Administration Medal (Gold) in 1983 and the Meritorious Service Medal in 2002.

He graduated with a Bachelor of Arts (Honours) in Philosophy, Political Science, Economics from Oxford University, UK. He also holds a Master of Arts from Oxford University, UK, and a Master in Public Administration from Harvard University, USA.