Health care systems worldwide are experiencing similar pressures such as rising cost, aging populations, and increased burden of disease. While policy makers in all countries face these challenges, their responses must consider local pressures, particularly the implicit social contract between the state, medicine, and insurers. We argue that public attitudes provide a window into the social context in which policy decisions are embedded. Using data from the International Social Survey Programme (ISSP), we compare public attitudes toward government involvement in health care in 21 countries, testing the associations between various national-level variables (e.g., health care expenditures, aging of population, health care traditions) and public opinions. Specifically, we posit four national-level hypotheses ("health care traditions," "expenditure crisis," "demographic crisis," "changing disease profile crisis"), one individual-level hypothesis ("individual vulnerability"), and two cross-level hypotheses ("cultural socialization" and "health care need"). Our findings indicate that public attitudes cluster around the historical organization of health care, but also relate to current economic and demographic realities. Individuals in countries adopting the "National Health Service Model" (the state directly provides health care but complete state control is absent) or the "Centralized Model" (the state directly provides health care and has much control) are more supportive of government involvement in health care than those in the "Insurance Model" (the state is limited to maintenance of the system) countries. However, citizens in countries currently spending more on health care and having a greater burden of chronic illness are less supportive. Our results cast doubt on arguments that increased cost will result in a questioning of the contract between the state and citizens in the social provision of health care. We end by discussing implications for recent work in political sociology that highlights the importance of public attitudes. (Contains 6 tables, 2 figures and 11 notes.)