Phua Kai Hong holds a joint appointment with the School of Medicine at NUS. He has worked previously as medical care administrator in the New York State Department of Health's Office of Health Systems Management, and the Ministry of Health, Singapore. He has served on various editorial boards of international journals, and on numerous national health policy and advisory committees in Singapore. He is also frequently consulted in health economics and financing by many governments within the region, public and international bodies, including the Asian Development Bank, Red Cross, WHO and World Bank.

He has published widely on policy issues of population ageing, health care management and comparative health systems, especially in the emerging economies of Asia. He is currently Chairman of the Executive Board, Asia-Pacific Health Economics Network and Vice-Chairman, Singapore Red Cross.