The paper shows the realization by Polish citizens the Community Law of the right for free movement of persons within the territory of the European Union (EU) and the European Economy Area (EEA) and its effects on the national health care system in Poland. The introduction to the subject of coordination of benefits in kind contains the short analysis of its main principles i.e.: equal treatment, one legislation applicative, retaining the acquired law and the law while acquisition as well as the cooperation of social security institutions of the member states. The article also reviews current problems concerning the realization of coordination of benefits in kind, the data concerning the number of documents certifying the right for benefits in kind issued for Polish citizens for a short term stay, a long term stay or a residence in other member state. There are also reviewed the financial effects of the coordination of benefits in kind for Poland.