Dr Lee is currently the Dy Group Chief Executive Officer (Regional Health Service) Singhealth and concurrently the CEO of Changi General Hospital. Prior to these appointments he was the Deputy Director of Medical Services for Health Services and Healthcare Performance in the Ministry of Health (MOH) Singapore where he led the strategic development and improvement of healthcare services. He is an Adjunct Professor with the Singapore University of Technology and Design and Adjunct Associate Professor in the Saw Swee Hock School of Public Health.
He is a member of several international committees and and chaired the subcommittee on Universal Coverage of the Medishield Life Review Committee. Dr Lee co-edited Singapore's Health Care System: What 50 Years Have Achieved (published 2015) and also contributed the chapter on Strategies for Health Services in the 6th edition of the Oxford Textbook of Public Health (2015).