Objectives: To analyze trends and patterns of the distribution of benefit incidence and out-of-pocket (OOP) payments for health care of individuals in relation to the distribution of household living standards prior to and after implementation of the policy on universal coverage (UC) in Thailand. Methods: Secondary data analyses of five nationally representative household surveys in Thailand, the 2000, 2002 and 2004 Household Socio-economic Surveys, and the 2001 and 2004 Health and Welfare Surveys, in pre-universal coverage period (2000-2001) and post-universal coverage period (2002-2004). Financial and benefit incidence of the entire population prior to and after universal coverage was analyzed. Results: After the implementation of the UC policy, the benefit incidence of public spending on health was more pro-poor, especially at the district health system which included health centers and district hospitals. In 2004, the concentration indexes of benefit incidence of ambulatory care was -0.3326, -0.2921, and -0.1496 for health centre, district hospitals, and provincial hospitals, respectively. Progressivity in benefit incidence of hospitalization at provincial hospitals was weaker, and its concentration index was -0.1104 and -0.1221 in 2001 and 2004, respectively. The incidence of catastrophic health expenditure (defined as OOP payments for health care more than 10% of total household consumption expenditure) reduced from 5.4% in 2000 to 3.3% and 2.8% in 2002 and 2004, respectively. Reduction in catastrophic incidence is a result of the policy on universal coverage which provides a comprehensive health insurance coverage for ambulatory services, hospital admissions, and other high cost care with a very small nominal fee. Three major policy interventions contributing to the pro-poor nature of health care systems in Thailand were: 1) the extension of health insurance coverage to the formal and informal sectors; 2) the extensive of geographical coverage of health service infrastructure; and 3) the mandatory rural services by all medical, nursing, pharmacists, and dental graduates. The current tax-funded UC scheme further fosters the pro-poor health care finance in Thailand