Professor Hsiao was born in Beijing, China and as a teenager emigrated to the United States, where his father was an economic advisor to the Kuomintang (KMT) delegation to the United Nations. He grew up in Forest Hills, Queens of New York City, and attended New York public schools. Following graduation from college, Professor Hsiao began his career as an actuary for Connecticut General Life Insurance Co. in Hartford CT, which was a predecessor company to CIGNA. Following this corporate stint, Professor Hsiao moved to Washington DC and was employed as an actuary to the Social Security Administration in 1968. When the Chief Actuary of the SSA resigned, Professor Hsiao was appointed the acting Chief Actuary in 1970.

During this time, the Social Security Administration was roiled by efforts by the United States Congress to reform the social security system and maintain its solvency. Professor Hsiao headed up two blue-ribbon panels and testified several times before Congress regarding the actuarial viability of the system under the funding mechanisms in place. Eventually, in 1977, the Congress passed and President Jimmy Carter signed into law one of the most comprehensive legislative efforts to bolster the Social security system.

Following this government service, Professor Hsiao commenced studies at the Harvard University Institute of Government, which later became the John F. Kennedy School of Government. He then entered the Ph.D program in the Department of Economics at Harvard University. His doctoral thesis was advised by Martin Feldstein, who later was Chair of the Council of Economic Advisors under President Ronald Reagan. Professor Hsiao was appointed to the faculty of the Harvard School of Public Health as an Assistant Professor in 1979. He became a full professor in 1986. He was appointed to the K.T. Li chaired professorship in 1992, named for the Taiwanese policy-maker Kwoh-Ting Li.

Among his many contributions to the fields of health care economics, policy, and social insurance was a landmark study called the Resource-Based Relative Value Study or RBRVS which examined the United States system of reimbursing physicians for medical services. RBRVS led to a series of articles published in the New England Journal of Medicine, one of the first times the prestigious journal had devoted an entire issue to articles on one subject. RBRVS led to a revolutionary reordering of physician reimbursement payments under Medicare Part B which was passed by Congress and signed into law in 1989.

Later, Professor Hsiao conducted studies of the social insurance and medical payment systems of a vast array of foreign countries and regions, including Singapore, Cyprus, Taiwan ( Republic of China), Canada, South Africa, the People's Republic of China, and Hong Kong ( SAR of People's Republic of China). He is considered one of the world's foremost experts on health care economics and financing and regularly advises U.S. government agencies, foreign governments and non-governmental organizations such as the World Bank, UNICEF, and the World Health Organization."

Professor Hsiao's recent studies include a demonstration project of a micro-health insurance plan in rural provinces in China. The program was highlighted in the Wall Street Journal. He is also working on designing three possible systems of universal care in Vermont.

• Program in Health Care Financing Website

• William Hsiao Harvard Website

• Wall Street Journal Article featuring rural health project