The article deals with the role played by health insurance companies within the health care systems in OECD countries, mainly in Germany, UK, the Netherlands and USA. It is based on theoretical classification of health care and the schemes and financing of universal and facultative parts and it derives the potential for health insurance companies for each of them. The article comprises also the typology of facultative private health insurance and the discussion about the benefits of facultative products in individual configuration variants of health care as well as the reasoning of the importance of a universal, solidary financed health care and three basic financing models. The article also discusses the potential synergies between the universal and facultative parts of the systems and the options arising for the Czech health care system.