OBJECTIVES: The potential role of private health care providers and privatization has been under heavy discussion in many countries. In the Hungarian health care, there was a clearly supporting health policy regarding the increasing role of private health care providers. The aim of the study is to analyze the market share of for-profit private sector from the public health insurance expenditures on medical services. METHODS: Data were derived from the nationwide administrative dataset of the National Health Insurance Fund Administration (OEP), the only health care financing agency in Hungary, covering the period 2006-2009. The analysis includes the medical provisions (primary care, health visitors, dental care, out- and inpatient care, home care, kidney dialysis, CT-MRI). We calculated the health insurance reimbursement according to the following categories of health care providers’ ownership status: local authorities, central government, for-profit companies and non-profit providers. RESULTS: In 2006 only 15.8 % (112.8 billion Hungarian Forint, HUF) of total expenditure for medical services went to for-profit private providers, 53.9 % to local authorities, 24.7 % to central government and 5.6 % to non-profit sector. For 2009, the market share of private for-profit health care providers increased to 30.9 % (222.3 billion HUF), the local authorities had 43.8 %, the central government 22.7 % and the non-profit sector 2.5 % market share. We found the largest increase of private for-profit health care providers in acute (from 0.8 % in 2006 to 14.3 in 2009) and chronic care (from 1.1 % in 2006 to 20.6 % in 2009). CONCLUSIONS: In line with the health policy objectives between 2006-2009, we found a significant increase of private for-profit companies from health insurance financing: they doubled their market share from 15.8 % (2006) to 30.9 % (2009). This increase was attributed to the “functional” privatization of acute and chronic care hospitals.